How do i reset the failsafe code in my 91 TSi awd A/t?

[99 gst 420a dsm]

I was getting a failsafe lock out in my 91 TSi awd (would only drive in 3rd and revurse) it was only seriously dirty auto trans fluid (clogged filter starving servos and what not) but i need to know how to reset the TCU so it unlocks the rest of the gears.

 

[Bobster66]

Stuck in 3rd gear is Limp Mode. To reset a TCU and clear the error codes all you have to do is remove the negative battery terminal.

 

[99 gst 420a dsm]

wow, i didnt know it was that simple

 

[99 gst 420a dsm]

update.... That didnt reset the TCU

 

[Bobster66]

Your problem then is a lot bigger than just the dirty fuild.

First thing you need to do is check what codes the TCU is giving or if the TCU is bad. Follow the link below for instructions. Note: if you get no reading at all the TCU is fried.

http://www.plymouthlaser.com/tcucodes.htm

 

[99 gst 420a dsm]

the code was for an inactive #3 shift servo, that means dirty fluid/ clogged filter startving the #3 servo.

 

[98TalonTSi]

Did you flush the trans...and by that I don't mean drain it and refill it. I know we hate going to shops...but sometimes you have to. There is a machine that will push all the fluid through until everything is clear.

 

[98TalonTSi]

On a side note, maybe it wouldn't be so bad to pull the valve body out and blow some air through it.
Then try resetting the battery again, as maybe it's still clogged..

 

[99 gst 420a dsm]

if it was going to reset it would have reset for a few feet at least, until it had time to get another error code, im saying that taking the battery off is not reseting it. i did it all, took it off and touched the terminals together, everything that would normaly reset the ecu, a TCU will be free to me, i just have to get out to the salvage yard. I take it that it will work from a non turbo car? and if the #3 shift servo is bad i can use a nonturbo servo also right?