95 GC Transmission Issues

[Ros]

Originally Posted by hastreiter

I am having my transmission computer replaced this Friday. ktcakes have you had any problems?

Any luck?

[ktcakes]

I am still problem-free...

[hastreiter]

My Jeep is in the body shop. A kid in a pick up backed out of a parking spot and hit me. I will have to wait a couple of weeks to install the TCU

[scalde]

It is funny how we all have the same problem. I went to cottmans transmission with the same symptoms as all of you. they charged me 85 dollars to replace a relay that was not it. they told me that it was an electrical problem and to go in on the following day to service the transmission to further diagnose, thats another 65 dollars. well i never did go back. since i have a background in electronics i thought that i could give it a shot and i found the problem! the problem is in the TCM a small metal case by the left foot of the transmission. there is a relay inside that fails and makes it go into shutdown. The thing is that there is an eeprom that needs to be programed by a certified tech if indeed you need to replace it. well to avoid any further costs i bypassed the relay just by placing a simple jumper and guess what it works. well i have driving my vehicle for two weeks with out any problems. I need to replace the relay since that is not a permanent fix. i guess i saved about 300 dollars. email me if you have any questions and i will be more than glad to help.

[hastreiter]

Do you have to open the TCM to do the bypass. Please give us non-mechanical people some more detail on how to do this bypass and if the TCM is readily accessable. I can't find it.

Thank you so much!

[scalde]

yes the tcm needs to be opened. the tcm is under the dash board on the left upper part of the firewall. it has an orange conector. to remove tcm from firewall you need to remove 2 nuts acessible from the engine compartment under the hood. i will take pictures and send them to you if you request.

[legartner]

Originally Posted by ktcakes

I am still problem-free...

Hey Cakes, sorry to take so long to reply, wife's been ill. I finally got around to checking the TCM. I was lucky enough to find one at a local salvage yard, ($19.00), I installed it myself, (two bolts and plug the cable in), then started the engine. I've been problem-free for almost three weeks now. I didn't have to have the TCM re-programmed and didn't have any other problems. Of course I'm waiting with held-breath for something to happen, but if not, I got off real cheap. Just wanted you to know how it came out and to thank you for your assist.

(P.S.) I would advise everone to change the TCM first when experiencing the same probles).

[fowlerl]

Originally Posted by hastreiter

KTCakes
Any luck?

I have a 1995 Gc Limited Orvis. Love it . But it has the same problem with the od light comming on and off. This problems starts in the fall and carries through the whole winter here in Ottawa. The transmission will not downshift as you pull up to a stop. It feels like it is in third and stays there . It will downshift manually but then it will upshift irregularly until it warms up. Then it is fine. I was led to believe it was a manual transmission throw out bearing sticking if that makes sense because if you give it gas it will clunk into first. ???? I tend to let it warm up adequately and drive softly at first in the winter and wait for spring and it goes away. I think someone mentioned earlier that it might be some sensor that is cold and not sending proper signals. this does make some sense as the Od light is going on and off.I hope this helps. Hey I know your pain. I am just happy how well it runs otherwise and how reliable it has been. ---My problem is wind noise comming from blower area that if you turn the fan on goes awayor if you slow down.It is wind noise for sure. I think is some sort of door in the air intake sytem not closing . Any one have an Idea? sorry about the length of my letter. Thanks LF

[legartner]

The problem I had was pretty much warm & cold weather, not just cold. The OD light would come on and stay on and the trans would not downshift when slowed. After shutting down and re-starting the engine, it would clear the light and work OK. I was lucky, I found a cheap fix. For $19.00 at a salvage yard, I picked up a TCM (Transmission Control Module) and bolted it on myself. I have been problem-free since mid November, so I assume that the TCM was the fix.

Originally Posted by fowlerl

I have a 1995 Gc Limited Orvis. Love it . But it has the same problem with the od light comming on and off. This problems starts in the fall and carries through the whole winter here in Ottawa. The transmission will not downshift as you pull up to a stop. It feels like it is in third and stays there . It will downshift manually but then it will upshift irregularly until it warms up. Then it is fine. I was led to believe it was a manual transmission throw out bearing sticking if that makes sense because if you give it gas it will clunk into first. ???? I tend to let it warm up adequately and drive softly at first in the winter and wait for spring and it goes away. I think someone mentioned earlier that it might be some sensor that is cold and not sending proper signals. this does make some sense as the Od light is going on and off.I hope this helps. Hey I know your pain. I am just happy how well it runs otherwise and how reliable it has been. ---My problem is wind noise comming from blower area that if you turn the fan on goes awayor if you slow down.It is wind noise for sure. I think is some sort of door in the air intake sytem not closing . Any one have an Idea? sorry about the length of my letter. Thanks LF

[c5tech]

Does anyone know which points on the relay in the tcm you use to bypass it with a jumper. This is the last hing I can think to do before a teardown.

[ktcakes]

I am still having no problems at all... well, my windshield is cracked now, but so what?! ;-)

[rpady]

scalde, would you please let me know which pins to jumper and are the relays available at a electonics shop. Thanks, Rob

[rpady]

Well, I never heard from schalde so i soldered a jumper wire from pin 1 to pin 3 of the relay on the TCM circuit board and the transmission is working great. I'm going to order a new relay from a local electonics shop but it could take awhile because they have to build up a minimum dollar amount order. I'll let you know how that goes. Good luck to all.

[tinker1121]

I am having the same problem with my 1994 GC. Actually started last year and will either start out in what feels like second gear or when driving, the OD light flashes and car shifts irratically. No rhyme or reason as to when it will do it, i.e. weather, temperature, time of year etc. Car only has 84,000 miles on it. Been to three garages and Cottman and no one knows the problem.

I did the the Fault code test by turning the ignition on off-on off and then on and counting the blinking OD light.
Looks like Code 26 (blinks 2 times - pauses - then 6 times.)

Code 26 is "governor pressure sensor offset drift".

Would changing the TCM fix my problem and what would a reputable garage charge to do this?

Today a new problem and it squeeled VERY loud when putting it in reverse for a short trip to the post office and then a few seconds again when putting it in drive.

Help!!!

[rpady]

Your problem sounds different so I would not go out on a limb to say that the TCM will fix it. I never could get a fault code. You could try to put a jumper wire from pin 1 to 3 at the relay on the TCM circuit board and see if it makes a difference. As far as your squeal, is it your serpentine belt and is the A/C on when it does it? My daughters '95 GC does it when the a/c is on and especially in reverse. Well, good luck.