As a Warranty Administrator/Technical Advisor, I get to deal with all types of transmission and vehicle issues that come up in the field. While my current responsibilities have me working behind a desk, I have spent time in the industry diagnosing, R&R, and rebuilding transmissions. In my current position, I do not have the luxury of driving the vehicle to experience what the customer is reporting. However, there are benefits of not being in the shop to deal with distractions, noise, and having the time to research data in-depth. Sometimes when you are stuck on a problem it is best to remove yourself from the situation to do a little research and approach from a different angle. We have all heard the internet definition of insanity as, "doing the same thing over and over again, expecting different results." The following are anecdotes about some of those kinds of cases.
I had a warranty claim come in for a 2006 Lexus LS430 with a A761 transmission that was having trouble on a fresh installation; the complaint was a "different" 3-2-1 downshift. I say different because sometimes it was a bind, sometimes it was a direct 3-1, and sometimes a mushy 3-2-1. Eventually this would set code P0756 (SS ?B' performance). Already having a new OEM valve body on this transmission, I made the quick decision that we were going to replace the transmission to solve this issue.
Fast-forward about six months later and I receive another claim on fresh install for a different 2006 Lexus LS430 with a A761 with same symptoms, but this time no code was set. This customer was confused because the transmission he had replaced with ours was experiencing the same complaint. He was a rebuilder that was convinced that the valve body was the problem with his original transmission, but fluid being black he decided to replace with a reman unit and be done. Now he was stuck; he did not believe a valve body or transmission would fix his problem and needed assistance to figure out the root cause.
This is where getting away from the problem helps. With no codes it was hard for me to do much with the information provided, but luckily, we have a good claim system that has a wealth of historical data. I started going through all claims in last few years for the A761 transmission and noticed this was a common complaint some with the same code, but some with just shift complaint and no code. Looking into what fixed them, I saw that some were sent valve bodies and never heard from again, while others received replacement transmissions. I spotted one case that only six months' prior had had the same complaint, but never contacted us back after the transmission was replaced. I decided to call the shop to discuss what happened after the install, and guess what? The replacement unit had the same problem!
The shop wanted some time to get some notes together and call me back. The shop owner and the tech explained to me all the checks they had done and had concluded that the TCM was bad. Unfortunately, a new TCM was on backorder, at least four weeks out. After installing a new TCM several weeks later they contacted me to let me know that it fixed the vehicle. Armed with this new information, I passed it on to the second shop. Since he was already convinced it was not a transmission problem, he decided to try the TCM. The second shop did call me back and said the new TCM fixed it. The vehicle left with a happy customer.
Since this first fix I have confirmed a dozen more fixes on 2005-2007 Lexus LS430 with harsh/sloppy 3-2-1 shifts, and some will have a performance code P0756. Thanks to being able to step away from the problem, do a little research on past claims, make a few phone calls, and shops taking their own time to help me, this was a solid fix.
The next head scratcher again seems simple on the surface. We had a 2009 Dodge 2500 with a 68RFE show up with around 20K miles on our reman transmission. Initial testing pulled codes P0740 (TCC out of range) and P0876 (UD pressure switch rationality), and the fluid was burnt. Both are performance codes and an easy button; the transmission needed replaced. The replacement unit was installed, and on the final road test codes P0740 and P0876 returned.
Well...darn. This did not make much sense. We use a new OEM pump, new OEM valve body, and new OEM solenoid pack on these units, so it must be a bad torque converter, right? Going with that logic did not explain the P0876 very well, however. It was time to step away again and research through previous claims with these codes.
I found one that mirrored this case; it was a fresh installation, had been replaced for the same codes, and the customer stated the fluid was burnt. However, this claim was closed with one final note stating, "Fixed wiring". There were no details regarding the wiring repair, so I the shop that was involved with that vehicle. Just as with the first example, this shop was more than helpful and they took time out of their busy day to review the old notes and confirmed that they had fixed two broken wires under the brake booster to fix both codes.
Sure enough, after I directed the shop working on the current vehicle to inspect for broken wires under the brake booster, that is exactly what they found! Problem solved. My third and final example involves a 2006 Jeep with a 42RLE. The customer reported a bind-up on the 1-2 shift when cold, P0218 (High temperature operation activated) and P0714 (transmission temp sensor intermittent) were the codes. This vehicle had about 600 miles on a reman transmission. I expected to call the shop, ask for fluid condition, check loose connections, and if all good send a new MLPS/temp sensor, do a quick learn for the bind and move on with the rest of my day. Simple.
This shop was beat down, tired, worn out, and done with this Jeep. The whole back story behind the vehicle is that same codes kept coming back in spite of new temp sensors, new vehicle wiring harness, new cooler, replaced PCM with "used salvage yard" unit, and finally a new remanufactured transmission. The codes always returned. This shop had tried everything to fix this problem, and they were at the end of the line.
After receiving this information, I knew that a new temp sensor would be a waste of time. I see codes frequently enough that I know what most of them without having to look them up, but for some reason P0714 did not ring a bell. I did know it was temp sensor related so I started to research it. There were only eight easy steps in the diagnostic tree, which I found to be incorrect on an important detail; it leads you to replace the solenoid pack and not the temp sensor/MLPS. We run into this from time to time with aftermarket service information, but I am lucky enough to have multiple sources to research.
After going through all the "fixed-in-vehicle" reports we have compiled, along with ATRA, ATSG, and Mitchell, I finally stumbled on something related to the issue on Identifix. The #1 confirmed fix was the TCM. Really? Yes, everyone reported the same problem: binding 1-2 shift cold, with code P0714. Identifix has an easy check for bad PCM; two steps and a voltmeter are all you need to diagnose.
So, after a quite simple test the PCM was replaced with a new OEM unit and everyone was happy.
The message that I want to get across to anyone trying to figure out a nagging problem that will not go away, and most of all costing money, time, and resources, is just?stop. Stop doing the same thing over and over. In all the examples I shared, I thought the fix was going to be a simple one. A few short phone calls, some paperwork research, and done. I was not expecting to find defeated, angry, and frustrated techs on the other end of the phone. Luckily from behind my desk I am able to separate myself from the problem, do some research, and most of all, get some help from some of the people reading this magazine and help others get these problem vehicles out of the shop.