1989 PCM pin out ?

[Shoman594]

Ok getting code 63 low tps input. Does that mean the cec detected a problem with that 5v?

Looks to be a orange with whit stripe.

The 2 others are green with yellow and black with white

When I move the wires around I never lose that 5v at the tps. Also when the car starts to warm up I can't get the engine to start to die by moving the wires.



Also is the 91 evtm online anywhere?

 

[pjtoledo]

what about the return side of the TPS?
if the 5v input is steady, an interruption in the ground line would cause the ground at the TPS to jump around . normally the ground would read zero.
if the ground line is interrupted there is no current flow thru the TPS, therefore no voltage drop, results in 5 v at both input and ground.

on a side note, my 91 will not start now. cranks with tach at 300. time to re-mount the DIS, and check for chipmunk damage.

 

[pjtoledo]

pull the connector off the computer and check continuity between pins 46 & 47 on the harness.. those are ground and TPS output. you should get smooth change as the throttle is moved. a steady reading between 26 & 46 which is TPS power and ground, and another variable reading between 26 & 47, probably opposite.

I've noticed there are differences in how some 91 and 94 signals are described, mix that with your 89 and we may have some unintended mis-information here.

 

[Shoman594]

Ok diving more I have 5v at pin 49 HEGO ground??? What the heck is this pcm is this pcm issues?

Also if I remember right any mtx ecu from 89 to 95 should work right?

 

[luigisho]

Also if I remember right any mtx ecu from 89 to 95 should work right?

yes all the mtx pcms are interchangeable