Hi,

I've tried to search around and just can't find the info I need.

I have a 1990 V6 Trooper with 260k.

For the last ten years it has had an intermittent issue with the transmission light coming on and running in to "limp-home-mode" (2nd gear only).
I had the transmission rebuilt - no change
I have had sensors and wire harness replaced - no change
when it happens a quick "flick" of the key off back to on (power cycle) will fit it.

I've now got a new issue where it will not idle well about half the time.
the other half it's perfect. It can die at park or when at a light.
and the Tach goes from 0-4000rpm - sometimes this happens while driving. I can find nothing logical to when it will or will not happen.

I've had it in the shop 3 times for this problem and am to the point of
giving up but thought I would try to replace the computer myself if it is easy.

My questions are:
1, How many computers are in the 1990 V6 Trooper XS?
2, Where is the computer in the vehicle?
3, Where should I buy one?
4, I know there is one between the seats is that it?

Thanks
Patrick

 

according to my Isuzu manual:
2.8L v6

(TCM) Control unit

Auto transmission control unit

Bosch no: 0 260 002 094
Code: IA
Isuzu part no: 8-96015-174-1
GM part no: 96 015 040

My diagram shows it located under the dash on left side of steering column..almost all the way over to the the painted side panel.
Side note: there is also a ECM in the center console for other functions..
The TCM is for auto trans control.

TCM controls engine speed as well so that sounds like you may be checking into the right item..
A TECH 1 is used to check trouble codes.