91 Voyager transmission Goes Into Limp Mode

On long trips (over 100 miles or so) the trans intermitently goes into limp mode (stuck in 2nd gear). When it does this, I have to stop,shut-off the ignition,start again, and then it goes through the gears. At the next stop light the process starts all over again. This does not happen on short trips around town. My transmission guy says that my transmission control module does not have cooling fins and he has never seen a plymouth module without cooling fins. He thinks that on long trips heat build-up is breaking down some components inside the module. He road-tested the trans and it was working good. The only thing that the code readout says is the trans is going into limp mode. He'll install a new module with cooling fins for $300. Has anyone else had this problem? I'd rather not get into the "Let's try this and see what happens routine."Thanks in advance,Ron

Reply to
ron
Loading thread data ...

There are pertty much 3 things that ou can have problems with:

1) The trans itself. These puppies break. And if you are on a non-rebuilt 1991, well chances are you are living on borrowed time.

2) The TCM. Again, if your TCM does not have fins, then it surely is very old. The newer one with fins can be "flashed" to the latest firmware for your van.

3) Wiring / Cable Harness. Corrosion on connectors, or even a bad wire after all these years.

If you are worried about the cost, then why not go to a wreker and see if you can get a TCM with fins from a similar van? Perhaps a 94 with the same engine as you have? You could pick that up for cheap, and give it a try.

Baring that, wiring problems can be a pain in the ass to find.

Do you have a trans oil booster cooler >On long trips (over 100 miles or so) the trans intermitently goes into

Reply to
NewMan

ron wrote: .............................................................. The only

Ron, There are no codes that say "I'm going into limp-in mode but don't know why" There are 44 codes and of these, 32 will cause limp-in mode. Each of these 32 gives a likely cause of a problem, and gives the technician a place to start his diagnosis. The Chrysler Powertrain Diagnostic Procedures manual gives a step by step troubleshooting procedure for each code. If you'd like a list of the codes I can send you one. If you can supply me with the actual code(s) that are stored I can also email you the diagnostic procedures.

Reply to
Steve

Steve wrote:> ron wrote:>

.............................................................. The only> > thing that the code readout says is the trans is going into limp mode.> > He'll install a new module with cooling fins for $300. Has anyone else> > had this problem? I'd rather not get into the "Let's try this and see> > what happens routine."Thanks in advance,Ron> >

Ron,> There are no codes that say "I'm going into limp-in mode but don't know > why" There are 44 codes and of these, 32 will cause limp-in mode. Each > of these 32 gives a likely cause of a problem, and gives the technician > a place to start his diagnosis. The Chrysler Powertrain Diagnostic > Procedures manual gives a step by step troubleshooting procedure for > each code. If you'd like a list of the codes I can send you one. If you > can supply me with the actual code(s) that are stored I can also email > you the diagnostic procedures.Steve,From what I hear, the old TCM's (with no cooling fins) don't give any information other than "I went into limp-in and I'm not going to tell you why".I'm going to try a new EATX Relay first before getting a new TCM. My transmission guy says there is nothing wrong with the trans that he can see. The trans was completely rebuilt at 135K (I'm surprised it lasted that long) and there is 25K on the rebuilt. The one good thing about this van is the 3.3L V-6 that has 160K and burns very little oil, leaks none, and runs strong. The only thing wrong with the 3.3L is trying to change the 3 plugs in the back.Thanks for the info,Ron

Reply to
ron

Steve wrote:> ron wrote:>

.............................................................. The only> > thing that the code readout says is the trans is going into limp mode.> > He'll install a new module with cooling fins for $300. Has anyone else> > had this problem? I'd rather not get into the "Let's try this and see> > what happens routine."Thanks in advance,Ron> >

Ron,> There are no codes that say "I'm going into limp-in mode but don't know > why" There are 44 codes and of these, 32 will cause limp-in mode. Each > of these 32 gives a likely cause of a problem, and gives the technician > a place to start his diagnosis. The Chrysler Powertrain Diagnostic > Procedures manual gives a step by step troubleshooting procedure for > each code. If you'd like a list of the codes I can send you one. If you > can supply me with the actual code(s) that are stored I can also email > you the diagnostic procedures.Steve,From what I hear, the old TCM's (with no cooling fins) don't give any information other than "I went into limp-in and I'm not going to tell you why".I'm going to try a new EATX Relay first before getting a new TCM. My transmission guy says there is nothing wrong with the trans that he can see. The trans was completely rebuilt at 135K (I'm surprised it lasted that long) and there is 25K on the rebuilt. The one good thing about this van is the 3.3L V-6 that has 160K and burns very little oil, leaks none, and runs strong. The only thing wrong with the 3.3L is trying to change the 3 plugs in the back.Thanks for the info,Ron

Reply to
ron

ron wrote: From what I hear, the old TCM's (with no cooling fins)

The only difference I know of between the TCM modules with and without fins is that the older finless modules can't be flashed, they require the chip to be changed to update it. I had a 1991 Gr. Voyager, and still have a 1992 Gr. Voyager. Both finless TCMs store codes quite well, as I've pulled codes from both.

Reply to
Steve

Reply to
jdoe

I have to burst your bubble and tell you this isn't true. Perhaps on the

1996 and later units they put that in, but the UPDATED 1995 and earlier TCM's will happily knock you down into limp mode, on the freeway, at 60Mph. I know this from experience. And despite the fun imagery, going into limp mode at 60Mph doesen't spit engine parts all over the place. Perhaps at 90, but can you even get a minivan to go 90? (other than the turbo ones)

Ted

Reply to
Ted Mittelstaedt

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.