mjollnir

How do you tell a PCM is dead?

OBD2 can't get any answer from it, any other method to test it standalone?

bigboykilroy

iTrader: (48)

Does the car start?
IF you are checking from the port make sure that you have power there, usually the cig lighter fuse.

mjollnir

Here is the state of the car for now



And where the harness is:



I don't have any other american car around to test my PCM, I live in Belgium and this project is for a 1981 Corvette

mjollnir

I also wired Ignition 1 and Ignition 0 to +12V. Still no answer from OBD2 scanner

badcoup

did you powert up the ob2 port

mjollnir

Do you mean the OBD2 pin 16 ? Yes

bigboykilroy

iTrader: (48)

Do you have a schematic you are working off of you can post up.
Just to make sure you are trying to power up the pcm without any of the sensors hooked up to the engine correct?

mjollnir

Yes, there are no sensor plugged.

Big red terminal of the harness to +12V BATTERY
Black wire terminals (2 of them) to GROUND
I provide +12V to B9 for IGNITION 0 and IGNITION 1

On the OBD2 side:
+12V from Battery on pin 16
data from Dark Green cable pin 58 PCM BLUE on pin 2
GROUND from battery on pin 4 and 5

All my positive feeds are fused by a 20A and there is no short circuit anymore

Nothing else