In-Depth Testing Reveals Obscure Ground Problem

By Chris Adams, Diagnostician

author1Chris Adams started with Certified Transmission in 1986 as an R&R technician, and currently works as our Diagnostic Trainer. His current duties involve training and advising our retail diagnosticians, as well as assisting in the research and development of our remanufactured products. He also holds ASE Master and L1 certifications.




Sometimes despite your best efforts you can still manage to shoot yourself in the foot. The following account is a prime example of this; while this happened on one specific vehicle, it could happen on any number of vehicles where the cause is the same, but could have different end results.

One of our shop locations had a 2011 Jeep Patriot that came in on the back of a tow truck. The customer stated that it started making noise and then quit moving. This one was an easy checkout; the vehicle didn’t move in any direction, had metallic-looking fluid, a horrendous bearing noise, and had a P0777 (secondary pressure control solenoid stuck on) code stored. Even though this one was pretty much a slam dunk in the way of diagnosis, we still needed to go through our complete evaluation procedure.

The Jeep is equipped with the 2.4L engine backed up by a JF011E CVT transaxle (the Nissan version is the RE0F10A). Since we started remanufacturing the CVT applications these transmissions have been selling really well. The Service Advisor contacted the customer and let them know the results of our evaluation, and how much the completed job would cost. The customer agreed to the repairs and the remanufactured unit was installed. After a R&R is completed, the job then gets handed off to me. One of the things we do in our evaluation is check to make sure the software calibration is current, and this one was not. There were updates to both the ECM and the TCM.

Each of our locations have a subscription to the Tech Authority website that we use for service information and programming, and we use the FCA J2534 software and a Snap-On pass-thru pro +4 to complete the required reprogramming for these applications. The next thing that needs to be done on these units (can be done before or after programming) is to initialize the CVT transmission with a capable scan tool, and in this case we use the Snap-On Zeus workstation. After the transmission is installed the TCM will set a P167A (calibration mismatch) DTC. This procedure only takes a couple minutes from start to finish, and then you can either clear the DTC or after a couple ignition cycles the code will go away on its own.

Now we were ready for the road test. It didn’t take long to notice that we still had a problem as the vehicle had a really bad rolling surge. I immediately returned to the shop so I could check the fluid level, hoping that maybe we didn’t get the fluid level to full, but this was not the case; the fluid was at the correct level. I took the scan tool and set up a custom data list of all the PIDS I thought I needed to look at, and went for another road test. This time I had an associate drive the vehicle so I could watch the scan data, and the vehicle was still exhibiting the rolling surge. Watching the scan data, I could not see anything that was causing it. I could see the results of the surge, and I could see what I thought was causing the CVT to surge, but I just could not comprehend why.

I could see that the PL solenoid monitored current and output current were going right along with the engine RPM and the primary pulley RPM, but was this the cause of the surge, or a result? I still did not see anything that would cause this, so I scrapped the custom data list and just brought up the entire PID list for the TCM instead. While the data updates at a slower rate when you are looking at so much data simultaneously, I had to do something different.
This time I conducted the road test without the aid of an associate and recorded a movie as the issue was happening. I reviewed the data when I got back to the shop. This time I could see a potential cause; the “unswitched battery voltage” was erratic and varying in output at right around .4 volts. (figure 1)


Figure 1

Next, I needed to see why this is happening and if this is the cause of the surge. Another part of our evaluation includes a battery and charging system test, and we use a Midtronics ESP-1000 analyzer which has been proven to work very well and even does a pretty accurate ripple test. I re-ran the test and everything passed (figure 2). Not wanting to leave anything to chance, I hooked up the scope and looked at AC voltage, and even with that the ripple was at an acceptable level. The thing that did catch my attention was that the zero point seemed to be in somewhat of a wave. At this point I was checking voltage drop on the ground side. When I removed the air intake tube so I could get to the main battery ground cable on the starter bolt, I saw this: (figure 3)


Figure 2


Figure 3

The technician attached the main battery ground up to the throttle body bracket that is mounted with rubber bushings on each side, rather than to the starter bolt right next to it. We moved the cable over to its proper location and the voltage drop looked good everywhere I had checked, so now it was time for another road test.

I could immediately tell that the problem was fixed, so I took another recording so I could use this case as a training tool with our technicians. (figure 4)


Figure 4

The PL solenoid current was smooth as was the engine and primary pulley speed. There were still some unswitched battery voltage irregularities but they were not affecting the operation of the transmission. I am suspecting that there might have still been some issue with the alternator function, but I have not had another one of the same vehicle that I could compare it to. I think we have all had our tails kicked by a bad ground, but this one had so much of a mechanical feeling effect of the operation of the unit that it really surprised me.

My initial reaction to this when I was driving it was that I was going to condemn the remanufactured unit, as I think it would have been a fairly easy call to make. As the manufacturers are adding more complexity to the electronic controls inside the transmission in the way of more solenoids and even pumps for the stop/start systems, the electrical current required to run the transmission keeps increasing. This in turn will require the entire electrical system to be in perfect working order to keep everything working as it was designed.

Careful Inspection Uncovers Other Shop’s Mistake

By John Griffin, Diagnostician

John has been with Certified Transmission since 1990 and is an ASE Certified Master Technician. John is married and has two sons. His hobbies include helping his son’s work on their Sport Compact, Figure 8 and Demolition Derby Cars.

I had a 2006 Ford Ranger towed into our shop with the complaint of the transmission slipping in both forward and reverse ranges. The truck was a 4 wheel drive and equipped with the 4.0 engine and a 5R55E transmission. This was a fleet vehicle with 201k miles on the odometer. Upon initial road test and analysis, the transmission did indeed slip in both directions. I observed dark and burnt fluid which signaled internal damage requiring replacement of the transmission.

After receiving authorization from the customer, the transmission was removed from the vehicle. Our shop policy includes instructions and a checklist of associated items to check anytime we remove a transmission. One thing that I started doing several years ago was to remove the flex plate for two reasons: 1. inspect the rear main engine oil seal, and 2. inspect the flex plate. When I clean off the surface that mates up to the crankshaft, often times there are signs of stress that will lead to a broken flex plate before it actually occurs. This example was not from this vehicle, but illustrates the point. (Figure 1) Our subject vehicle’s flex plate looked good, so the transmission cooler was flushed with a Hot Flush machine and I was ready to install our remanufactured unit into the vehicle. I always use high temp grease on the converter pilot and the dowel pins when installing a transmission.

Figure 1

The truck had passed the electrical system analysis, so the PCM was updated with the latest calibration using a J2534 device and the FJDS software. Having completed these tasks, I was ready to road test the vehicle. Our normal road test consists of both in-town and highway driving, and everything was working as expected. The truck passed all of our final checks for proper installation. This vehicle was ready to deliver to the customer to be put back in service.

Fast-forward about five weeks and 2,000 miles. I received a call from our customer explaining that the truck now had a grinding noise that sounded like it was coming from the bellhousing. I submitted a tow to get the truck back to our shop ASAP to find out what had happened.

When the vehicle arrived at the shop, when attempting to start the truck it emitted a very unpleasant grinding noise. We pushed it into the shop for further inspection. All the bolts were tight, and everything looked like it was supposed to. I then removed the starter for further inspection. When attempting to turn over the engine using a pry bar on the teeth of the flex plate I could see that the flex plate was broken and the transmission would have to be removed for inspection.

After the transmission and flex plate were removed I saw that the entire center was broken out. The converter nuts and flex plate bolts were all tight, nothing was pinched in the bellhousing, the dowel pins and the holes in the case were in good shape, so this lead me to suspect some type of alignment issue. I removed the torque converter and sent it to our converter shop to have it checked.

The converter passed inspection, but a remanufactured converter was sent to replace it just to be sure. With no root cause for the breakage yet identified, I had to determine what may have broken the flex plate in such a short amount of time. I ordered a new flex plate and crankshaft spacer due to damage from the broken flex plate. The backing plate between the engine and transmission was inspected for signs of distortion. I broke out the dial indicator to check crankshaft endplay and runout.

The crankshaft endplay spec is between .002-.0126″ and was within that spec, as was the runout. (Figure 2) Still left without any direct cause identified, I was thinking that maybe the flywheel was just stressed from the 200k miles of service, but I had to be sure. I brought out the straight edge and checked the face of the transmission which mates to the engine. Again, everything checked out good. Next I checked the rear of the engine block which mates to the transmission. As the straight edge was moving down the rear of the engine to the oil pan it stopped; the engine oil pan seemed to be projecting out past the engine block mating surface!
(Figures 3 & 4)

Figure 2


Figure 3


Figure 4

This was a problem since the transmission also mates to the engine oil pan, but couldn’t explain why is it hadn’t broken the flex plate prior to the transmission replacement. A phone call to the customer explaining what I found shed some light on the situation. The customer explained to us that a short time after I installed our transmission it went to another repair shop for engine work. The engine had been removed and one of the repairs involved the engine oil pan being removed. At this point I received authorization to remove the oil pan and inspect.

I had found upon removing the oil pan that the oil pan bolts had enough wiggle room in the bolt holes to shift the pan past the mating surface of the block. I installed a new pan gasket with a straight edge at the back of the block to make sure the oil pan was flush. I installed the new adapter and flex plate and proceeded to install the transmission. Once the installation was completed and double checked, the truck was road tested several times and brought back in to check for noises and leaks. The truck was returned to our customer in good working order. It has been five months since the repairs were done on this truck, and no further flex plate problems have arisen. The truck is still in service and is seen occasionally driving by the shop.

Circuit Testing A Must

By Dana Deeke, Diagnostician

author9Dana joined with Certified Transmission in 1991. Dana has worked in all positions at the Lincoln location, starting as an R&R technician and is now our current diagnostician for our Lincoln, NE facility. He enjoys car racing and spending time with family and friends.




A customer brought in a 2010 Dodge Journey AWD with the high-output 3.5 V6 engine and the 62TE automatic transmission. With a little over 83,000 miles on the odometer, the complaint was for no upshifts and stuck in 3rd-gear failsafe mode. This concern had started out as an intermittent issue but now had become more regular.

The preliminary visual inspection was performed and a diagnostic tool was connected to scan for codes in the electronic systems. The fluid level was noted as being a little low and there was a slight transmission cooler line leak. The condition of the fluid was still red in color. The scan tool pulled several DTCs as follows: P0765 (underdrive solenoid circuit), P0750 (low/reverse solenoid circuit), P0562 (battery system voltage low), and P0755 (2-4 solenoid circuit). There were also some body control codes set: B21A1 (ECU reset) and B25AC (door module not calibrated). We try to make sure we always scan all systems when scanning for codes rather than just concentrating on the engine and transmission; it is a practice that has served us well over the years.

As you can see, not only were there codes relating to the transmission, there were body control codes also. Sometimes these other codes can be a great clue to a problem in another system. After recording the code data, they were cleared and the vehicle was road tested to check the operation. After a very short time the Journey went into failsafe mode again, but this time it had only set P0562. After doing a little research I found the set criteria and the possible causes for this code. (Figure 1)


Figure 1

As shown, there are multiple causes for this code. A common cause for this code is a gradually failing battery or alternator with voltage that falls below 10.0 volts for 15 seconds. One of the things we do as part of our routine checkout is a battery and charging system test. Today’s vehicles are very sensitive to battery voltage changes, especially low voltage, and excessive AC ripple. We have seen many issues caused by excessive alternator ripple, ranging everything from codes to erratic speedometer operation and erratic shifting.

We also checked the grounds for corrosion and that they were tight. Once in a while we can get wrapped up in finding a complicated electrical issue and overlook the simple things, like poor ground paths. In this case everything checked out so we moved on to the next step: a battery and charging system test.

For these tests we use a Midtronics battery and charging system tester. It showed that the battery was in good health and that the starting and charging systems were operating as they should, without any excessive ripple. Feeling pretty confident in the battery and charging system integrity, we continued our search. Since the diagnostic information indicated that the code will set if the PCM has commanded the TIPM to energize the transmission control output, and it did not see the expected voltage on the transmission control output sense circuit, we went to the TIPM (totally integrated power module) located under the hood on the driver’s side of the vehicle. (Figure 2)


Figure 2

We used the wiring diagram for the subject vehicle to determine which connector on the TIPM was the correct for testing. The back of the TIPM was accessed to make it easier for testing. (Figure 3)


Figure 3

We are focusing on circuit T16: the transmission control output circuit. This circuit branches off in three legs from the PCM. There is a connector C105 and C101 between the PCM and the TIPM. I wanted to verify that the TIPM was energizing the transmission control output. This happens on the Yellow/Orange wire from the transmission control relay in the TIPM. We used the snap on scope to monitor power and hopefully catch any quick dropouts in power. With key on engine running I was able to confirm that the TIPM was in fact sending out the signal on T16.

I left the scope connected at that location and added another channel to monitor voltage on T16 at the transmission solenoid. After doing several cycles of the key and starting the engine each time, we eventually lost voltage at the transmission solenoid. Since we had both channels going at the same time, we saw that power remained constant coming out of the TIPM. Channel 1 is the TIPM and channel 2 is the transmission solenoid pack. (Figure 4)


Figure 4

Having verified that the PCM was sending the command, and that the TIPM was receiving the command then sending the signal output, it was apparent that the signal was not reaching the transmission solenoid assembly. This led us to looking at the wiring and connectors that were left in the circuit. With the scope still attached at the previous points and the engine running we started moving wires while watching for any voltage changes. At this point the vehicle had come out of limp and of course we had power at both points that the scope was hooked to. After a few minutes of run time while wiggling wires, the vehicle again went to failsafe mode and set the P0562 code.

After working our way along the wire loom we arrived at a connector that when moved, we could duplicate the power loss repeatedly. . Connector C101 is found near the PCM on the top of the transmission. (Figure 5)


Figure 5

The connector was taken apart to check for damage or corrosion on the pins. The connector appeared to be sealed with no damage to the weather pack seal. No corrosion was found. However, the pin fit from male to female was not very tight. Once we isolated the area of the problem, a new wire connection was temporarily made to go around the loose pin at C101. The vehicle was tested multiple times and no more issues were noted. A complete system scan showed no codes present. It has been out on the road for several months now and after checking in with the owner it has worked without incident.

Since the time we had diagnosed and repaired this vehicle, we have had another come in that had the same code and symptoms. It was found to have the same connection problem at the same connector. If you have one of these vehicles come into your shop with this concern, make sure you verify the presence of voltage where it needs to be, and if there is a loss, where it is being lost. While these do have some common problems with TIPM failures as well as PCM issues, take the time to isolate the problem and you may just find a connector issue like I did. I am sure there are other Chrysler vehicles that may have a similar setup to this Journey, so it would certainly be worth your time to take a look.

Nissan CVT RE0F10A/JF011E Electronics

By Chris Adams, Diagnostic Trainer

Chris Adams started with Certified Transmission in 1986 as an R&R technician, and currently works as our Diagnostic Trainer. His current duties involve training and advising our retail diagnosticians, as well as assisting in the research and development of our remanufactured products. He is also holds ASE Master and L1 certifications 

As CVT transmissions are appearing in our shops with increasing frequency, there still seems to be a degree of hesitance for some shops to take on these jobs. Even if shops do not want to build these units in-house, there are reliable sources for remanufactured units out there that enable them to capture profit on R&R rather than sending a customer down the road to a competitor. Shops must be able to diagnose the correct operation of the unit, and in a nutshell, it is a relatively straightforward process. There are only four solenoids, and two of them are for TCC operation. There are two pressure sensors that are really easy to verify operation (at least after a gauge or pressure transducer is connected), and we will get into those details later in the article. Lastly, there is a stepper motor in place to control the variable ratios of the transmission. The stepper motor is what is new to us transmission guys, and while some stepper motors can get extremely complicated, the ones used in the Nissan/Chrysler applications are not.

The RE0F10A/JF011E transmission utilizes a two-phase unipolar stepper, each with two windings and a center tap for each phase. This type of arrangement allows the magnetic pole to be reversed without reversing the direction of current; the center tap is “common” and only requires a single transistor for each winding. The motor is driven in what is called a “full step drive” which means two phases are always on at one time, which results in a higher torque output than the other methods that will have finer control, or resolution. The stepper motor is very reliable by design and could be compared to a brushless DC motor. For our purposes, it is mainly the windings and the bearings that we have to worry about as they must operate within a hostile work environment. The following photos are the stepper motor partially taken apart:

There are a few ways to test a stepper motor on the bench. A simple resistance check is one of them, and since I have never seen the specs posted, we will cover that first. Refer to (figure 3). Measuring between each leg (phase) should produce a result of 15 Ω. If you connect a DMM between pins 1 and 2 you will get 15 Ω (figure 4), and connecting between 1 and 3 and you will see 30 Ω. Pins 2 and 5 are the grounds so it doesn’t really matter which side you start from; the second pin in from either side will be a ground. This is just a quick test to make sure you do not have an open or short, and I would always try to run the motor in and out for more of a “live” test (be sure to use some type of controller; do not just apply a direct 12v to these circuits as these windings use a very fine wire and can heat up quickly).

There are stepper motor controllers that can be purchased that are used only for running the motor in and out, but another option is to build your own if you really like to tinker with stuff. I am not going to go into all the specifics here but there are kits you can buy that utilize either Arduino or Raspberry Pi boards, and a simple web search will turn out tons of results including videos that will show you how to build it. For this application you need a six-wire unipolar stepper motor controller.

Now we’ll move on to some cool screenshots from the scope. The top section on each of these screen captures is the main view which has the entire recording in it, and the bottom section is the zoom view which will only show a focused section from the main view. This scope has math functions built-in that allows for measuring the results from any point, either between cursors for a Duty % or Hz reading, or at a specific point for a voltage reading. We are using ten channels, four for the solenoids, four for the stepper motor, and the last two are Pico pressure transducers connected to the primary and secondary pulley pressures. When Certified Transmission prepared for remanufacturing these units, we had to make a reliable, repeatable, dynometer test and that was the driving force for us to gather this information.

The following capture is a 0-70 mph run that was a total of 46 seconds, and you can see how the stepper motor is more active at the start and gradually slows down as the ratio stabilizes. The zoom window only contains two seconds of operation.


Figure 5

The next capture is close to the same recording time as above, but we used the manual shift option where you can see clearly defined ratio changes for each gear selected. The zoom window is only one second of the main window, so the completed ratio change from the theoretical 1-2 gear shift took just a little over .7 seconds to complete.


Figure 6

Displaying Park, Drive, Drive Stall, Neutral in this capture shows TCC on/off solenoid responding to the gear selector changes, and since the vehicle never moved there is no operation of the stepper motor control. This is where we obtained the pressure specs for the Pri/Sec Pulley pressure. At stall the PC solenoid is running at 15% +duty and the secondary PC solenoid is basically shut off. These readings result in 248psi at the primary pulley, and 410psi at the secondary pulley. At Idle the PC solenoid is running at 45%+ and secondary PC is at 36%+. Corresponding pressures are primary 138psi and secondary 197psi. All three of the PWM solenoids run at 800Hz.


Figure 7

A word about pressure testing: BE CAREFUL! Although some of the pressure taps on this unit can be tested with the same equipment that you have used for years, there are others that you can’t. I haven’t put this unit into failsafe mode to see what would happen, but just normal operation of the Ford CFT30 transmission (as an example) can run close to 900psi of pressure. If you own a Snap-On Verus or the newer Zeus scan tool, they offer a 0-5000psi transducer that is actually reasonably priced and you can look at the pressure on the scope and enables recording pressure events. Make sure you have hoses that can handle these high pressures as 800psi of hot CVT fluid is nothing to mess around with. We have always gone by the 200% rule, so all of our hoses used for CVT testing have a minimum 2000psi burst rating for safety.

These transmissions are getting common in the field. Adequate training, understanding, equipment, and software are the basic requirements for a modern shop to have in order to survive in the latest wave of technology. While these transmissions are certainly more complicated, working on them doesn’t have to be.

Improper Remote Start Installation Causes Transmission Concerns

By Daniel Skinner, Diagnostician

Daniel is a Diagnostician for Certified Transmission’s Blue Springs, MO shop. 





As we see numerous cars come into our shops on a daily basis, we often have a diagnosis already in mind based on the customer’s complaint, the type of vehicle we’re working on, road test experience, and symptoms. That’s the benefit of specialized repair. Sometimes the actual in-depth diagnosis proves us right, and sometimes proves us dead-wrong.

A critical part of an accurate diagnosis by the technician relies on the initial interaction between the customer and a skilled service advisor. A good advisor knows how to get details about the problem from the customer, including valuable information that the customer might otherwise feel is insignificant or unimportant. Sometimes these seemingly insignificant details are the clues that lead us to the solution. Sometimes even the best advisor still can’t get all of the details from the customer, or at least up front.

Such was the case with the 2004 Chevrolet Tahoe that found its way into our shop. The customer’s stated concern was that intermittently the vehicle barely moves while accelerating, high RPM at highway speeds, and a check engine light is on.

Upon performing an initial evaluation I found the vehicle to have these codes: P0740 (TCC solenoid circuit), P0785 (3-2 shift/timing solenoid problem), and P2791 (TCC PCS solenoid control circuit present (Figure 1)


Figure 1

Previous experience with this code set led me to believe there was a high probability that I had an ignition switch problem at hand. I was anticipating circuit 1020 from the ignition switch would have a low voltage condition when tested as this would be typical if the ignition switch was bad. A simple voltage test would confirm my hypothesis, and would result in an easy fix.

I immediately went to the “IGN 0” fuse to check voltage as I had done so many times before (Figure 2). Testing with the key on, I had 12.28 volts (Figure 3) and no codes reset. Thinking that a failing ignition switch circuit may only fail after being under load for a period of time, I drove the vehicle while monitoring voltage on circuit 1020. After test-driving the vehicle two different times for over an hour and totaling 60 miles, no codes had reset and circuit 1020 voltage never dropped below system voltage.


Figure 2


Figure 3

Now I’m scratching my head. This must be a VERY intermittent problem! After discussing my findings with my service advisor, we elect to call the customer back and find out just how frequently this problem is happening. To our surprise, the customer states that it happens almost EVERY DAY! He even experienced the problem on his way to the shop this morning. At the very end of the conversation with the customer, he stated, “It probably doesn’t have anything to do with [the problem] but I recently had a remote start put on the vehicle. (Figure 4)”


Figure 4

When asked, he stated that he uses the remote start nearly every morning before leaving for work. To the customer this may not have had anything to do with his transmission problem. For me trying to diagnose the problem, this was the smoking gun.

Having installed remote start systems myself in the past, I knew that a remote start module is used to power up several circuits coming from the ignition switch in order to enable the engine to start and run. Back to the “IGN 0” fuse I went. With the key off, obviously I had zero volts. When I activated the remote start function, the engine started and ran, but I still had zero volts at circuit 1020. Codes P0740, P0785, and P2791 finally set as well. Problem found!

A look under the dash revealed a maze of wires running every different direction from the ignition switch harness to the remote start module. After digging into the mess, I found the pink wire for circuit 1020 untouched. No wire had been spliced into circuit 1020 (from the remote start module) to provide power during remote start activation. Whoever installed the remote start system failed to connect a power source to circuit 1020. With the PCM powered up and seeing no voltage on circuit 1020 during remote start activation, the PCM then sets the three codes and puts the transmission into fail-safe mode. This explains the customer’s complaint of “pushing on the gas/barely moves and high RPM on the highway.” A pan inspection revealed nothing detrimental inside the transmission. We recommended servicing the transmission at this point and advised the customer to NOT to use the remote start system until he returned to the installer to have it correctly wired.

This is why we follow through and truly diagnose the problem regardless of speculation. Had I replaced the ignition switch based on GM’s known ignition switch failures and my previous experience with them, the customer would have been back within a day or two complaining of the same problem. Worse yet, he may have been unhappy with us and would be lost as a customer forever.

One of the most valuable tools in our industry is communication with the customer. Had my service advisor not been able to reveal the information regarding the remote start on this vehicle, we may still be trying to figure out why we cannot duplicate the problem. We always ask about any recent work done to the vehicle. We now have a line on our customer/vehicle information sheet that asks about any aftermarket anti-theft or remote start systems that might have been installed. Both of these help by opening up conversation with the customer that might assist us in diagnosing the problem more efficiently. Sometimes it is the small details that help us the most.

Our customer left happy that he did not need a transmission. He was happy that we took the extra time to correctly diagnose his problem, but the last thing he said before leaving our shop was, “Now that I think about it, the problem only happened when I used the remote start!” Insert face-palm here.

2011 Ford F150 Electrical Diagnosis

By Mike Greer, Diagnostician

author10Mike has been with Certified Transmission since 1996, and been in the industry since 1987. He is an ASE master Technician and has served as a Master Builder for the company in the past.  





A customer recently brought his 2011 Ford F150 into our facility after a general repair shop (not a specialized transmission shop) had just installed a used transmission. His truck was a 4WD vehicle equipped with a 5.0L engine and 6R80 transmission. When the customer picked up the truck from the previous shop he was told that the transmission was installed and everything was fine, but it still needed to be programmed (the shop didn’t have the equipment to perform this important step).

This is a fairly similar story that one of my colleagues wrote about a few months ago about a Jeep, but with a couple of added twists. We are seeing programming requests like this more often with the 6 and 8-speeds that are showing up at our stores as the 6-speed applications are aging, and with the higher mileage put on these vehicles, we seem to have more customers trying to get by with the cheapest options that are out there. Customers are turning to general repair shops with lower labor rates, and elect to install used parts from unknown origins or mileage instead of having a professional transmission tech repair, rebuild, or replace the transmission with high-quality components.

When this customer showed up at our facility and told the service advisor the whole story, we knew it was not going to be as simple as, “The shop that installed it said it needed to be flashed.” The customer stated that he went to the other shop with a complaint of a check engine light on, no power from a stop, and no shifting. Can you guess what symptoms were after the used unit was installed? You guessed it…a CEL light on, no power from a stop, and no shifting.

When I started the evaluation and scanned the vehicle for codes, it had P0657, P0770 and P0773 stored in memory <FIG 1>. I had no way of knowing whether or not these codes were set in the system prior to the used transmission installation, or generated after. We told the customer that we would need a couple of hours of diagnostic time to pinpoint the issue. Since the diagnostic time was an added cost over and above the PCM programming, the customer requested that we simply program it first. After we made it clear that he would be charged for the programming even if it did not fix the issue, he acknowledged this and I proceeded forward with the customer request.


I hooked up the Ford IDS scan tool and determined that there was a later calibration available. I proceeded to reprogram the module and it appeared to go through the steps normally, just like any other vehicle with this engine/transmission combo. Programming was successful, but when I went back to scan and clear codes I was shocked to see that now the PCM had 16 different codes stored and they appeared to be every possible solenoid electrical code that the system was capable of generating. What?! I went back to the programming screen and it displayed, “Later calibration available.” How could that be? I had just programmed it and had no errors! Reluctantly, I decided to run through the programming routine again. Unfortunately, I landed at the same result as before.

It would seem that I made the issue worse than when I began this adventure. Remember years ago when OBD2 was new and we were always told to fix the lowest numerical code first when there were multiple DTCs set? It just so happens that the lowest numerical code on this truck was one of the codes stored when it first showed up: P0657 (Actuator Supply Voltage ”A” Circuit Open), so let’s start there.

This next part would have been a little easier if I had printed off the correct connector view. While I knew that I needed C1381T, for some reason I printed off C1381E which was still a PCM connector and looked very similar to the “T” but the wire position of pin 50 was not in the same location. After a few minutes of trying to figure out why the wire color was not correct and why the PCM pin 50 seemed to be a ground rather than a B+ supply, I got the correct connector view and started over again.

I had B+ at pin 50 of the C1381T connector, but nothing down at the transmission connector pin 7. I performed a visual inspection which did not reveal anything out of the ordinary. Sometimes you see a missing wire harness retaining clip or it’s obvious that something had just been worked on, but I was a little surprised that the installation of this unit was actually very good; everything was put in its place just like OE, and I saw nothing that really raised suspicion. Since access to the wire loom was pretty tight I decided to remove the loom from the truck and work on it on the bench, and found this: Figure 2 & Figure 3 Below (in order).



The loom had rubbed through against the bellhousing just forward of the loom clip hole on the case. <FIG 4> shows where the loom was rubbing and wore through. After seeing where it was, I might have been able to repair it in the vehicle, but I still think it was a better repair off the vehicle. After the wire was repaired and the loom installed back into the truck, I was able to clear codes and none of them returned right away. I hooked up the IDS to check programming again, since the last programming session left me with “Later calibration available” displayed after programming. However, after repairing the loom, “No later calibration available” was displayed so I buttoned everything up and went for a road test. Hoping for the customer’s sake that everything was operational, the transmission worked well and no codes had returned. The customer stopped in a few days ago and wanted to thank us for repairing his truck correctly, and let us know everything had been working well.


The question remains as to whether the original transmission was actually in need of replacement. All too often the shop makes assumptions and drives up the cost of repairs due to misdiagnosis. With modern vehicles that are more technologically advanced than ever before, we must take the time to find the root cause of customers’ vehicle concerns. This involves helping the customer understand why they will need to pay a few hundred dollars to diagnose; it could save them thousands. The days of a $50 diagnostic charge are long gone.

Mini Cooper Transmission Shift Control Diagnosis

By Darrell Puls, Diagnostician

author33Darrell began his transmission repair career in 2000 as an installation technician at the age of 17. Following a 6-year career in the U.S. Navy, he resumed working in transmission repair and completed a bachelor’s degree in Organizational Leadership. He is an ASE Master Certified Technician + L1, currently working as a Diagnostician for Certified Transmission.



We’ve all had those days where you roll into the shop ready to start the day and see a car waiting for you there in the parking lot and think, “Well, that look like trouble.” When I came in to find a 2005 Mini Cooper waiting for me I felt my hopes for a peaceful morning wash away a just little bit.

The service adviser transcribed the customer’s complaint as “Stuck in manual mode”, and it was coming from a shop that didn’t want to work on it. After chiseling the Midwest winter ice off the vehicle I was able to go through my initial check-out. I found code P0705 stored in the PCM (Transmission Position Sensor (P R N D L) Malfunction). Park, reverse, and neutral all functioned the way I expected them to, but the drive indicator did not illuminate when selected. However, the manual mode indicator did illuminate when drive was selected, but without moving the shifter over into manual mode. I also noted on the road test that the CVT would not change ratio in drive but would change ratio as designed when switched to manual mode, and shifted manually. Everything else on the car seemed to check out fine.

Normally, having a hard code set and duplicating the customer’s concern right away ends in an easy evaluation, but that wasn’t the case this time around. Just as I would for a relevant code on any check-out, I looked up the code description and set criteria but found nothing even remotely helpful. I checked a few forums and a couple of subscribed information sources for any leads. My fears were confirmed. I was finding that, like many European cars, there really wasn’t much information out there for me. Identifix is usually a reliable source for decent wiring diagrams, and luckily, I happened to find one. (Figure 1)


Figure 1

After looking over the diagram I was able to get a basic idea of how the system works, and as it turned out, was pretty simple. Armed with a little more knowledge, I prepared for my diagnostic routine. First, I wanted to ensure signal voltage was getting to pins 3,4,5,6, and 9. Second, I wanted to verify pin 2 was a good ground. Feeling confident I could figure this situation out, I asked the service adviser to sell some diagnostic time.

With my time authorized and wiring diagram in hand, I set out to get to the bottom of the situation. I pulled the center console out of the vehicle and located the shifter harness. I then looked for the brown/blue wire at pin 3 of the range sensor, labeled as “Park +”. I was attempting to establish what the correct signals should look like, but guess what? None of the wire colors matched the diagram! This forced me to methodically work through the connector and write down what wires went where, and how the signals changed with range selection. I expected to see voltage on each wire when its corresponding range is not selected, then have the signal drop to 0v once selected. I had verified that pin 2 was a good ground by conducting a voltage drop test. I did find a couple things about the sensor’s normal operation that I wasn’t expecting.

First of all, the range sensor looks different than the conventional design I was used to. The shifter stick has a magnet on a spring which slides across the sensor. When shifting to manual mode the shifter is pushed to the right, and the magnet comes out of contact with the sensor. Figure 2 shows what should be drive. Figure 3 shows manual mode with the magnet relieved from the surface. If you have taken a close look at a 6R80 range sensor, it uses a magnet in a similar way minus pulling away to activate manual mode.


Figure 2



Figure 3

The second thing I was not expecting was the sensor voltages were very low by design. Open signal was only few tenths of a volt, right around 400mV. Voltage would drop to ground when the corresponding range position was selected, just as I expected.

Now that I had established a pattern of how the signals operated, I was able to pinpoint the cause. The anomaly I found was the manual mode signal wire never had any voltage no matter where the selector was. I put a little extra force on the shifter handle toward the sensor, and when the magnet was closer to the sensor, the signal for manual mode would come in and out intermittently. Simultaneously, scan data would indicate manual mode off (Figure 4). It seemed that the shifter bushings had just a tiny bit too much play in them, or perhaps the sensor’s sensitivity to the magnet wasn’t what it should be. With the sensor and the shifter being serviced and sold only as a complete assembly, I had our diagnosis in hand.


Figure 4

We contacted our local Mini dealer and procured a new O.E.M. shifter assembly. Should be easy from here on out, right? Nope, it’s a Mini. Things got a little weirder since the shifter assembly installs from the underside of the vehicle. Sigh. With the new shifter in place I conducted a quick version of my previous testing to verify the repair. The same change in signals was present through the drive ranges and the manual modes operated and canceled the way they were supposed to.

We delivered the repaired vehicle back to the owner and received some praise for fixing something another shop was unwilling to tackle. Not much information was available, but in the end not much was really required. Stepping out into a situation with little service information can present some major challenges when trying to diagnose a problem. Stopping and taking a moment to analyze what you’re really working with may show that it’s not so complicated after all. Sometimes we just have to figure it out.

Routine Diagnostics Discover Faulty PCM

By Dan Frazier, Diagnostician

frazier-danDan has been in the automotive industry for over thirty years and is an ASE Certified Master Technician. Dan has a college background in electronics engineering and specializes in diagnostics and computer controls for Certified Transmission.

We all have routines. We live, eat, sleep, play and work by them. They help us get things done faster and more efficiently. Sometimes they are the fabric that holds us together, sometimes not so much. Anyone that’s been around this profession for any amount of time probably knows that the next ticket in the queue has a good chance of being anything but a routine repair.

Such was the case with a 2005 Dodge Dakota that rolled in to our shop equipped with 4WD, 4.7L engine, and a 545RFE transmission. Trucks like these are our bread and butter being located on the border of a big city with lots of farming and commercial operations on the other side. The customer’s complaint was “It feels like it’s slipping once in a while.” We have a routine for our initial evaluation like everyone else: check fluid levels, scan for codes, test drive, and perform an undercar inspection. While checking fluid levels I noticed this: A new/reman PCM (figure 1). Possibly not that it is relevant at this point, but something to make note of.


Another of our routines starts at the counter when the service advisor is getting information from the customer. We ask a specific question: have you had any other work done on your vehicle in the last year? You may or may not be surprised at the answers you will get. Our front office staff is pretty good about prying information out of the customer, but a lot of times the information that the customer provides is grossly inaccurate and that can make a difference between having an accurate concern identified on the repair order or what I like to call a, “search warrant”. This customer had stated that he had not had any repairs done recently, so let’s move on with our initial inspection.

Fluid levels are good and the transmission fluid looks pretty fresh. Almost too fresh for 178K on the clock, and there are multiple codes stored in several modules. O2 heater B1S1 sensor, no closed loop operation, SKIM key code not stored, and on the transmission side we have a P0869 line pressure high, P0988 4C pressure switch rationality, and P0888, transmission relay always off. There were also codes stored in the airbag and ABS modules for lost communication with the PCM.

Moving on with the road test, things seemed pretty normal. The transmission shifted ok until a few minutes in. I usually record a data capture while test driving, but before I knew it the vehicle went into limp mode and the scanner had lost communication. At that time I still had communication between all the other modules except for the PCM. Cycling the key seemed to restore normal operation, so I decided to clear all the codes and start from scratch. It didn’t take long for the PCM to start acting up again. After a short test drive it went into limp mode and the P0888 (transmission relay always off) returned as a pending code. At that same time I also lost communication with the PCM on my scan tool and it also reset the lost communication codes for the CAN C bus in the ABS and airbag modules.

At this point I knew I needed some diagnostic time to figure out what was going on. After getting additional diagnostic time approved it was time to decide where I wanted to go with this. Did the loss of communication cause limp mode and the P0888, or did the egg come before the chicken?

If the PCM has a problem with communication I’m going to verify the basics: powers, grounds, data lines, and then make a determination based on what I find. If I find some new parts installed on a vehicle I always start with the installation of the parts involved. I accessed the new PCM and lo and behold, what did I find? (figure 2)


See that connector on the right that is not fully seated? Notice that the connector locks for the other connectors aren’t locked either. The loose connector on this configuration is C1; a pretty important connector on Chrysler systems. Guess what it supplies to the PCM? Data lines? Check. Most of the power and grounds? Check.

I seated the connector and heard that “click” that we all like to hear when we connect something and re-checked my work. No such luck, but I thought I’d get lucky and earn my hour or so of diagnostic time but now I have to get the brain cells out.

At this point I’m concerned about the functionality of the PCM. With the loss of communication resulting in limp mode, coupled with the loss of communication codes stored in the ABS and airbag modules tells me we needed to check the basic functions of the PCM. Looking at the schematic for the CAN C lines, the only modules on that circuit are the PCM, ABS, and airbag modules that communicate to the scanner via the TIPM. On a lot of vehicles, you can scope the CAN lines straight from the DLC pins 6 and 14, however on this common Chrysler setup pins 6 and 14 only communicate with the TIPM. The CAN signals from there are transmitted to the other modules on the CAN C network. (figure 3)

Figure 3

I decided that I needed to verify the CAN networks ability to transmit and receive messages as well as verifying the correct powers and grounds that will let the PCM function as designed. The easiest thing to do (I like easy) was to scope the CAN signals at a couple of modules to verify there is a signal present. I hooked up my lab scope to the CAN+ and CAN at the PCM and ABS modules to compare signals. (figure 4).


We can see that the CAN HI signal is being pulled from 3.5v to 2.5v, CAN LOW is pulled up from 1.5v to 2.5v. The top capture was taken at the PCM; the bottom capture was taken at the ABS module. The signals indicate that the CAN network is intact, and there are no discrepancies in the waveform. From there, I verified correct voltage supply to the PCM, and all grounds voltage dropped at less than 5mv, which is actually pretty good for a 13 yr old vehicle. These readings were all taken while the condition was occurring, leading me to believe that this PCM had internal issues.

A remanufactured PCM was ordered from a fairly reputable supplier that we’ve used in the past. After installing the new PCM, the engine had a definite misfire and set a P2313 – insufficient coil burn time on cyl #8. Yep, the new PCM had a bad coil driver for that cylinder. It ran fine with the original PCM, so we got another one on the way. I’m very hesitant to install used or reman PCMs (especially on Chrysler products) because I’ve seen way too many issues that have resulted in a new problem after the PCM is replaced.

After replacing the PCM once again, the engine ran like a champ, the transmission shifted great, and test drove a few times for about an hour total and no transmission codes had set. The O2 sensor code returned, but the customer is kind of a DIY guy and said he would take care of it himself.

Fortunately, this diagnosis was fairly easy. Being able to reproduce the issue along with an understanding of how the system works and a logical diagnostic path to follow helped a lot, not to mention that the components in question were easily accessible. This one is out the door and now it is time to move on to the next routine diagnosis.

Hidden Wiring Problems Cause Lights And Codes

By Troy Hopp, Diagnostician


Troy has been in the automotive repair industry his entire career and has been with Certified Transmission since February 2010. He has an Applied Science Degree in Automotive Technology from Western Iowa Tech and is an ASE Master Certified Technician.


About two months ago a customer brought in his 2006 Ford E350 Econoline van equipped with a 5.4L engine and a 4R75E transmission for an evaluation. His concern was that the check engine light was on and the transmission seemed to shift hard at times. We always begin our evaluation with a battery and charging system test with a Midtronics electrical system analyzer, and we scan all modules for codes using a Snap-On Verus Pro if we are not using an OE scan tool. After a quick visual inspection of the vehicle and checking the engine oil level, we will proceed with the road-test.

After scanning the PCM, I pulled two codes that were stored: P0740 (Torque Converter Clutch fault) and P0743 (Torque Converter Clutch System Electrical fault). The fluid level was correct, but it was dark red in color with a slightly varnished smell. My next step was to clear the codes and try to duplicate the customer’s concern. After driving the van about 5 minutes, the torque converter clutch started to shudder and I could see on the scan tool that the torque converter clutch was slipping. P0740 and P0743 both reset and the transmission began to shift hard because it went into limp in mode. At this point I was fairly confident that the problem was a slipping torque converter clutch, but to be absolutely sure I obtained the customer’s permission to perform a visual pan inspection. A quick removal of the pan revealed a large amount of metal and clutch debris confirming an internal transmission failure.

After explaining the course of repair to the customer and obtaining repair authorization, we replaced the defective transmission with our remanufactured unit. All of our transmission installations include hot-flushing the oil coolers to ensure complete debris removal from the entire system. We also reprogram the powertrain and/or transmission control modules to the latest calibration for optimal operation. While the transmission is removed we also thoroughly inspect the flex plate, rear main seal, engine mounts, transmission mounts, u-joints and/or CV joints to ensure everything is in good working order and replace them if needed, then complete the installation of our remanufactured transmission.

With the installation completed and all of the updates performed, it was time for a final road-test to make sure the customer’s concerns were all alleviated. The 25-minute road-test verified that the torque converter clutch no longer shuddered or slipped and the transmission shifted and operated perfectly. However, after getting the van back to the shop, a quick scan of the codes revealed that the P0740 code was had not returned, but the P0743 code had. It was now apparent that the van had two different issues at play.

I cleared the code once again and went for another road-test, but this time I had another technician with me to monitor the scan tool for PCM commands while I drove the vehicle. For the first several minutes everything was working just fine, but the converter clutch seemed to apply earlier than it had on the previous road-test, so I asked the tech if the TCC was commanded on. He stated that it was not, so it seemed we were getting our scope narrowed down to an electrical issue. A quick scan for codes showed that the P0743 had returned so then we returned to the shop.

At this point I was comfortable to assume that the P0743 code was most likely caused by an external wiring problem, or possibly by the PCM itself. Since the torque converter clutch was apparently being commanded on and off by the PCM properly, the PCM was not my first suspect. I felt it was safe to assume the PCM was ok based (in part) of the fact that we rarely have to replace a PCM in a Ford application, so I first decided to direct my attention to the wiring harness and connectors.

After a close visual inspection of the connectors at the transmission and at the PCM, I verified that they were clean and the terminals were tight and making good contact. When I back-probed the TCC solenoid control wire at the PCM with KOEO, I had full battery voltage and the circuit seemed to ohm out fine, but something had to be amiss that these tests did not reveal. I decided it was time to inspect the wiring harness, but of course no problems were found where the harness was easily accessible. Removal of the engine cover (dog house) was required for a complete inspection of the wiring harness.

Once the engine cover was removed it was revealed that the harness was lying against the EGR tube and had melted through the harness conduit and into the insulation on the torque converter clutch solenoid wire, thus causing it to ground out through the EGR tube and setting the P0743 code.

I cannot completely explain the intermittent nature of this issue or why it would just act up when it was hot, but can theorize that the EGR tube only made enough contact with the wire when there was some heat expansion of the pipe, or just from some movement while driving. (Figure 1)


Figure 1

I repaired the shorted wire, replaced the conduit where it was melted and properly secured the harness away from the EGR tube. Now it was time to reinstall the engine cover and take the van out for another final road-test. I drove the van for 30 minutes and the transmission shifted and operated ok, the check engine light stayed off, and no codes were reset. Now both of the codes were repaired, the customer picked up his van and was on his way.





Beware Of Component Variations For High-Performance Transmissions

By Allen Channel, Diagnostician

author32Allen grew up under the wings of his father. He worked in his father’s shop starting out washing parts and cleaning. He soon was working on cars, but more specifically, transmissions. He eventually took over the business and ran it for many years. He later went to work for a Chevrolet dealership performing most of the transmission repairs. He left his native state of Ohio and joined Certified Transmission in May, 2015. He is currently our diagnostician in our Blue Springs, MO location. 


In addition to the OEM-spec remanufactured transmissions we build, we also offer a series of heavy-duty transmissions available in three different stages. The subject of this article is in regard to the installation of our Road Ripper™ 3000 (stage 3 unit) in a 2005 Dodge 2500 Pickup equipped with a 5.9L diesel and a 618/48RE transmission. The vehicle had been in use for about a month when the customer returned with an issue that the transmission was stuck in gear and would not shift. We did not want any damage to occur by the customer driving the vehicle to our location, so we set up a tow to have the vehicle picked up.

During my initial evaluation, everything appeared to be normal. Prior to the road test I hooked up the scan tool so I could scan all the modules, and to my surprise there were no diagnostic trouble codes stored. at this point a road test was in order, and as I prepared the scan tool for monitoring I looked at the data menu and noticed the governor pressure was at 98.4 psi with the key on engine off (KOEO), and the transmission throttle valve actuator (TTVA) was at 99%.

This data appeared to indicate an issue with the electronic governor pressure system, so I installed a pressure gauge to the governor port and the indicated pressure was at 0 psi as opposed to the nearly 100psi that the scan tool showed. I test drove the truck and the governor pressure did not come off 0 psi regardless of speed (at least the speed I could get to when it is not shifting). Although the scanner shows 98.4 psi all the time and TTVA is always 99%, the transmission is in a default mode and the transmission won?t shift out of 1st gear. After a short test drive I rechecked for codes and none were found.

The reason there were no codes is because electronically the system was within correct parameters and I did not drive it far or long enough for it to set the P1762 governor pressure offset code. With this information we could conclude that the sensor was not giving us accurate information as originally suspected, but when I looked at the transmission temperature it was working correctly which told me the ground was intact for the sensor (Fig 1), since the pressure sensor and temperature sensor share a common ground. I checked the 5 volt reference at pin 2 (yellow & pink wire) and the voltage was correct. I then checked the sensor signal wire at pin 4 (yellow & brown) wire, and it read 4.75 volts which is very near reference voltage (Fig 2). The correct reading should be about 0.7 volts KOEO. The pressure sensor works similar to a throttle position sensor, except it uses fluid pressure to change its voltage output instead of a mechanical device.

Figure 1


Figure 2


At this time I determined we would need to check the components inside the pan. When I pulled the pan everything looked good and nothing abnormal was found. I did a visual inspection of the internal wiring and everything looked in order. We keep the sensors in stock at the store, so as a quick test, I plugged a new sensor in and the scanner immediately showed 0 psi for governor and the TTVA went to 0%. I plugged the old sensor back in and reading went back to 98.4 on governor and 99% TTVA. I was able to see a change for the better and then to verify the part I was replacing was definitely faulty.

I replaced the governor sensor, installed the pan and went for a road test. The governor pressure was now correct and transmission is shifting great again. Problem solved, or so I thought. Remember when I said earlier this is a Road Ripper™ 3000? Whenever there is a warranty issue, we submit a claim to our warranty department which reviews the concern and makes the recommendation for repair. Our warranty technician reviewed the repair and sent a message back stating since this is a Road Ripper™ 3000 unit, and therefore requires a special high-pressure sensor. The OE-style pressure sensor would work, but eventually the diaphragm will not survive with the higher pressures the Road Ripper™ 3000 is set up with.

We ordered a high pressure sensor from Rostra, and once the sensor arrived I realized how to tell a high-pressure sensor from a stock (OE) sensor. The stock sensor is all black, but the high-pressure version has a white cover on it (Figs 3&4).

Figure 3


Figure 4


Had we installed the OE-style sensor, the transmission would have worked for a while, but for how long is hard to tell. Thanks to our knowledgeable technical department, they were able to let us know about the discrepancy before we delivered the vehicle to the customer and had a potential governor issue down the road. This is another example of a system of checks and balances to ensure a positive customer experience, and when several people are involved there is a better chance something won’t be overlooked.

The repairs were completed, pressure testing and road testing were completed, and the vehicle was ready to be returned to the customer with the confidence that we had fixed it right, the first time.

The takeaway from this experience highlights the need to identify any special circumstances that may impact the overall quality of repair. While the diagnosis was routine and basic, overlooking the fact that this high-performance unit used a non-OEM spec part could have created a comeback situation down the road. An effective check-and-balance system saved the day on this one, and will again for a future day.