Galant GSX AWD N/A 4g63 A/T limp mode

[slikvik]

I have tried searching and have had no luck fixing my problem. It is not the average limp mode problem. The car will run great then go into limp mode (stuck in 3rd gear) after driving around for 5-10min. But if I pull over and turn the car off then on again, it will run great for another 5-10 min before going into limp mode again. I can do this all day.

So far I have replaced the ECU and ISC. The last ISC had a bad coil which burnt the original ecu. Even with the bad ECU and ISC I still had this problem. I was really hoping that replacing the ECU and ISC would have solved my problem, but it didn't. I have checked the ECU and ISC just now to make sure that they did not get toast again, and they checked out fine.

Logically I checked the TCU out, but it was rebuilt in 2006 with all new caps, according to the writing on the cover. The caps and board look brand new, which lead me to believe that it's not my problem. I tried pulling codes but it's really hard to tell with my digital multimeter if I even have any. There is no check engine light either.

Has anyone ever experienced this? I have checked for loose connections, and nothing. I have also checked the 10amp fuse by the kick panel and its also fine.

Any help is greatly appreciated. If you have suggestions on what I should check next I would love to hear it. Thanks.

 

[Bud92gsx]

Have you tried swapping in a good tcu, to check and see if it is the tcu?

I mean it's not the usual limp mode problem, but it will would still piss me off..

 

[slikvik]

Have you tried swapping in a good tcu, to check and see if it is the tcu?

I mean it's not the usual limp mode problem, but it will would still piss me off..

Tell me about it. It's driving me nuts. But I have not tried a different TCU. I might have to buy one to see if it is the TCU.

 

[Bud92gsx]

Go to the junk yard see if you can't pull a tcu out of an auto 4g63 car..And try that..

 

[slikvik]

Go to the junk yard see if you can't pull a tcu out of an auto 4g63 car..And try that..

That's going to be my next move. I will begin the search for another TCU.

 

[Bud92gsx]

That's what I would do first is find another tcu and rule out a good or bad tcu first..

 

[transdude]

I have tried searching and have had no luck fixing my problem. It is not the average limp mode problem. The car will run great then go into limp mode (stuck in 3rd gear) after driving around for 5-10min. But if I pull over and turn the car off then on again, it will run great for another 5-10 min before going into limp mode again. I can do this all day.

So far I have replaced the ECU and ISC. The last ISC had a bad coil which burnt the original ecu. Even with the bad ECU and ISC I still had this problem. I was really hoping that replacing the ECU and ISC would have solved my problem, but it didn't. I have checked the ECU and ISC just now to make sure that they did not get toast again, and they checked out fine.

Logically I checked the TCU out, but it was rebuilt in 2006 with all new caps, according to the writing on the cover. The caps and board look brand new, which lead me to believe that it's not my problem. I tried pulling codes but it's really hard to tell with my digital multimeter if I even have any. There is no check engine light either.

Has anyone ever experienced this? I have checked for loose connections, and nothing. I have also checked the 10amp fuse by the kick panel and its also fine.

Any help is greatly appreciated. If you have suggestions on what I should check next I would love to hear it. Thanks.

This is absolutely insane. You're pulling your computer apart, etc but you didn't even get the code(s) yet.

If you can't get them out take it somewhere that can.

There is a proper diagnostic sequence in which things need to be done, it's not about guesswork and throwing parts at a problem.

TIP: If a mulitmeter is giving you a hard time reading the codes, go to Radio Shack and buy a 12V buzzer and try it that way. Probably under $5

-John
IPT Performance Transmissions
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[MY1GDSM]

Not sure how your not getting any codes but as John Said your going at this all backwards...

If your not sure your pulling the codes correctly read this it should help... TCU Codes

Also Just for reference See here if it is a TCU problem your not going to be able to throw in any TCU... It's also my understanding that the N/a A/t GSX's had a W4A32 trans not W4A33 like the Turbo Variants...

 

[Bud92gsx]

I did not realize tht the glant gsx 4g63 tranny ws different..I guess he my be going at the problem all wrong..Cause a wrong tcu will not help..Good thing you guys new that..

 

[slikvik]

UPDATE:

I pulled the TCU apart first because everywhere I looked people said that the 1g tcu's where notorious for leaking capacitors.

I got a second TCU which I know is good. I still have the same problem. So the next thing I did was pull the codes. I am getting the same two codes on both TCU's. So it's pretty obvious that the TCU can be ruled out for the problem.

The two codes I pulled where 51 and 86. According to the code pulling page:

Code (51)

* Check Connectors of Pulse Generators A and B and the generators themselves
* Rear Clutch Slipping

Code (86) See related codes (51,52,53,54)

My next question is, what are the resistance's supposed to be for the pulse generators?

I'm leaning towards the problem being the rear clutch slipping because the car won't go into limp mode unless I am at WOT for an extended period of time. If I stay out of WOT the car will not go into limp mode and will run fine.

 

[transdude]

UPDATE:

I pulled the TCU apart first because everywhere I looked people said that the 1g tcu's where notorious for leaking capacitors.

I got a second TCU which I know is good. I still have the same problem. So the next thing I did was pull the codes. I am getting the same two codes on both TCU's. So it's pretty obvious that the TCU can be ruled out for the problem.

The two codes I pulled where 51 and 86. According to the code pulling page:

Code (51)

* Check Connectors of Pulse Generators A and B and the generators themselves
* Rear Clutch Slipping

Code (86) See related codes (51,52,53,54)

My next question is, what are the resistance's supposed to be for the pulse generators?

I'm leaning towards the problem being the rear clutch slipping because the car won't go into limp mode unless I am at WOT for an extended period of time. If I stay out of WOT the car will not go into limp mode and will run fine.

You almost certainly have an internal transmission problem.

-John
IPT Performance Transmissions
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IPT Performance Trans Blog

 

[slikvik]

You almost certainly have an internal transmission problem.

-John
IPT Performance Transmissions
Facebook- IPT Performance Transmissions
IPT Transmissions YouTube Channel
IPT Performance Trans Blog

^That's what I was afraid of^

I had plans to turbo the galant and swap in a turbo trans anyways, but it looks like I can start looking for the components to do the swap earlier than expected.

I'm going to try one last thing though. I'm going to swap the trans filter and oil with oem counterparts.

Thanks for all the help guys.

 

[the_mork]

Not a bad idea generally, but probably a waste of money in this case. Fluid and filter together get expensive. It is time to change the transmission because even if things get better it wont last.