Transmission control module location

It is on the right inner fender its right up on top, with three rectangular plugs. It is just a few inches forward of the right hood hinge.

What kind of problem are you trying to solve?

Check out the diagrams (Below). Cheers

The first thing to try to do is determine exactly what is taking place when it drops into limp mode. Most commonly that is during an up-shift to a higher gear. When the clutch plates are worn to the end of their life, excessive slippage takes place, and the computer detects that before final full lock-up occurs. You can work around that by accelerating a little harder than normal, then letting up on the accelerator pedal for a few seconds to let the next higher clutch pack lock up solidly under no load. Once firmly engaged, then accelerate the same way to the next gear. That is not fixing anything. It is just helping you get by for another few thousand miles, but the real solution is to rebuild the transmission.

If it ever goes into limp mode right away, before you even start moving, it is almost always due to a sensor or wiring/connector terminal problem. The computer detected that defect when no clutch pack is engaged yet.

There are two things you can do first, but it involves a mechanic with a scanner that can access the transmission computer. Definitely do not unplug the computer or disconnect the battery. Either of those will lose power to the computer which will erase its valuable stored data. The first thing your mechanic must do is to read and record the diagnostic fault codes. Those will give us an idea of where to start the diagnosis. The next is to read the "Clutch Volume Index, (CVI). That is a set of four numbers corresponding to the volume of fluid it takes to apply each of the four clutch packs. An experienced transmission specialist can tell by those how much life is left in the transmission. You may want to visit a transmission specialty shop for this. Reading all this data only takes a few minutes, but you need someone who knows how to interpret it.

I have a 1993 Dynasty, twin to your model, and I have a Chrysler DRB3 scanner for all of my vehicles, so I know how to retrieve the data, but not how to interpret the CVI numbers.

The purpose of limp mode is to keep it in second gear specifically so you can drive slowly to a repair shop without needing a tow truck. It will never come out of limp mode on its own while you are driving. The only way to do that is to turn the ignition switch off, then restart the engine. If it is coming out of limp mode while you are driving, that would point to an intermittent bad connection causing power to be lost to the Transmission Computer. That is where knowing the diagnostic fault code numbers is helpful. Without that information, there is no way to know which circuit or system needs to be diagnosed.

If you think that is it without diagnosing anything first, get a used one from a salvage yard. It will plug right in with no need for any kind of programming to your car. Go by the application, not the part number. There were many revisions to these computers, and each time one was sent in for repair, it got all the updates and a new part number.

Did it fix the problem?

Yes, on the first post (above) in the diagrams below click to enlarge it.

I finally figured out the problem. If you look at that diagram way up at the beginning, it is wrong. It is a mirror image of the correct module location. It shows the receiver/drier for the AC system right in front of the module, but that is on the passenger side, just like where I said the module lives. It is right in front of the passenger side hood hinge, bolted to the inner fender.

Be aware there is a relearn period after power is lost for this computer. It has to learn the volume in CC's of fluid it takes to apply each of the four clutch packs. That is the "clutch volume index", CVI I mentioned earlier. By knowing that, when a clutch pack has badly-worn plates, it takes more fluid to apply that clutch, and that takes more time. It will update and modify its shift schedules to engage third gear, for example, then wait a fuzz longer than normal before releasing second gear. That longer overlap results in a nice clean, solid shift like when it was new, right up to the time it cannot update any further, then the slippage occurs and it goes to limp mode. The disadvantage to this is you do not get to feel that slippage as "engine runaway" like we had years ago before these computer controls. We used to get a good two or three years of mushy shifts as a warning that a transmission rebuild was in our future. Not any more.

We were always told at the Chrysler schools that the shifts could be real sloppy or soft, or harsh like those of an older muscle car, for the first two miles or about a dozen up-shift cycles, but in actual practice, it was rare to observe anything unusual at all. This does not apply only to replacing the computer. It applies to any Chrysler model with a Transmission Computer when the battery is disconnected to replace it or for any other routine service. We were always told that if the work we performed did not require a test drive, we were to do one anyway to do that relearn for customer satisfaction. That directive went away over the years because it just was not necessary. My reason for mentioning this is I am worried you have worn clutch packs and the new computer is not going to solve anything. I hope I am wrong, and if I am, I do not want you to be concerned if the shifting does not feel right, right away. If it no longer goes into limp mode, drive the car a few miles before evaluating the shift quality.

Besides all the different part numbers these computers can have, some have finned heat sinks on the side and some do not. My 1993 Dynasty did not have the heat sink, and when I mentioned one of the ten common "irritants" about shift quality, I learned there was updated software that could be installed, but only those computers with the heat sink could be "flashed" with that new software. I got a new computer with the heat sink, under warranty, then I put the new software in it at the dealership I worked for. Unfortunately it did not change anything, but compared to some cars I have driven, mine has nothing to whine and snivel about.