2G Another limp mode...tcu

[Bluefire16]

Someone suggested unplugging the battery cables, so i did and still in limp mode. The weird thing was I i relocated my battery to the trunk but had the cable running under the car, so i rerouted it under the carpet and turned the car on and everything was fine no CEL. Two hours later i am going for a drive and i notice its not shifting higher than second. Any ideas other than replacing the TCU? I have a 99 gst eclipse and the tranny was just rebulit with 2k or less. Where can i get a new TCU if i need one?

 

[gofer]

check your local junkyards

im running an A/T as well and have never had problems with it shifting but id point at the TCU to be the culprit of your problems. i think there might be a solution and you can get something out of it too (and it might be cheaper than a junkyard TCU as well)

http://www.dsmtuners.com/forums/automatic-tranny/276470-manual-shift-box-automatics.html#post151340661

you might want to pm eagletalontim (the guy who made the shift box for the A/T) but im pretty sure if you wire the shift box up you control when to shift and the TCU does nothing.

 

[Bluefire16]

I emailed him and that would be nice if it would work, but the point of getting a automatic was so i dont have to shift..... not like pushing a button is hard but some days after work i would still rather not deal with it...

 

[Bluefire16]

Anyone with any other ideas? I unplugged the battery and it still is in limp mode, i haven't had time to bring it to Autozone to check the code but i will tomorrow probably.... If i replace the TCU and it still doesn't fix it then what could be the problem?

 

[Bluefire16]

Went to autozone, found out the codes where p1715 (malfunction control transmission) and p1500 (speed sensor idle control) The speed sensor was just replaced like 1k ago.... this help at all?

 

[95longneckrs]

RELAYS! - yep behind the master cylinder...
I have a 95 RS that would go in limp mode seemingly whenever it wanted. No prior warning. I could even make it do it in the driveway just by power brakeing.
I did a lot of reading, changed fluid & filter and nothing. When it happens I can pull over, shut the car off for about a minute and it's good to go again for another mile or two.
In my research I found one post where he replaced the relay for the TCU. It is located behind the master cylinder on the firewall. Apparently a 3 relay combination is more common, but mine has four. Any generic Chrysler type relay will work, just replace the 3rd relay from the left (ETAX) and hopefully that will take care of it. I fixed mine this weekend and so far 200miles plus and so far no problems.

relay configuration.
3-relay Fuel Pump, ASD, ETAX
in the attached diagram (A-68, A-69, A-70)
4-relay Fuel Pump, ASD, ETAX, Back-up light

Good luck - hope it works for you!

 

[2GBurntOrange]

How would I be able to test the Etax Relay? or where would I be able to find one?

 

[Ethenp23]

Went to autozone, found out the codes where p1715 (malfunction control transmission) and p1500 (speed sensor idle control) The speed sensor was just replaced like 1k ago.... this help at all?

Hey man it’s been a long time but did you ever find the solution???