1G TCU Question

[Eagleboyrox]

I just bought a 91 Talon 2.0 Auto without turbo for $500. I just got rid of my 91 Laser 2.0 with turbo because it was smacked up. I saved some parts though. This Talon I bought just had the tranny replaced but the guy who replaced the tranny did something and messed up the tcu. It's stuck in 2nd gear and when I ran a code reader on the car it says it's the tcu causing the problem. Anyone know if there's a way to reset or reprogram the tcu without having to go out and buy a new one? Or does anyone know if I could use the one from the turbo laser?

 

[98TalonTSi]

Pulling the battey as if you were resetting the ECU codes works the same for the TCU...

 

[Bobster66]

Disconecting the battery will reset the TCU error codes but it will not solve the problems that created the error in the first place.

The TCU for your Turbo is different than the TCU for your non-Turbo. They are not interchangable.

 

[Jumpmaster]

First I would make sure he put the right tranny in. If it's the wrong tranny (my car is a 93 1.8 with an identical looking 93 2.0 tranny) and it starts out sluggishly shifting then right away locks up in third ... limp or safe mode.

Here's a site which tells the number that should be on your tranny (top of tranny just to the left of where the 2 fluid cooling hoses go in) (a 91 non-turbo 2.0 should be F4A222 MPD1) ... the tranny's may look identical but internally they are apparently not. I got a lot of people saying that tranny's were interchangeable when in fact they were not....perhaps the guy you got it from had the same experience.

Tranny Interchangeability

This may not apply to you if you're tranny's right... but if you find that the wrong tranny was installed in your ride you may have to get the right tranny. Furthermore, if what I'm told is true, each tranny has it's own TCU and since the transmission numbers are different for turbo and non-turbo ... I wouldn't think changing the TCU would help but might be worth a try if you have one handy.

I'm told (but waiting on another thread for someone to confirm this) .... but again I'M TOLD ... that the transmission control unit (TCU) operates the tranny and is specific to each tranny. However, you can't just change the TCU because it uses engine sensors that are shared with the car's ECU. Again I'M TOLD that if you change the sensors to match the new TCU they won't communicate properly with the ECU ... and the ECU cannot be changed at all because I'M TOLD that the car's harness is different. Sure would be nice if simply changing the TCU to match the tranny would work because that would be quick and easy ... but I've NOT been TOLD that

Also check to see that the two transmission sensor wires are not reversed or it'll go into limp mode as described above.

I'm no expert and just learning the hard way, so seriously don't rely solely on anything I say ... just trying to help with the little I've learned.