I have a 96 Coupe, LT1, Auto, that's close to dead stock. I've been using the shop manual to try to troubleshoot a no-start. I've also done a couple of items suggested in past forums.
Here's what I know, then I'll get to the questions.
I can bypass the starter relay (sometimes refered to as the UTD relay) under the dash near the steering column and the motor will crank and start. Unfortunately it runs anywhere from 2 to 6 seconds then quits. I'm assuming this means the fuel system is also being disabled.
I have replaced the relay with a new one.
I've checked both key resister pellets, they are identical, and I get the same resistance value if I check the two wires on leaving the stearing column, so the ignition switch is ok.
I can set the alarm, open a door, alarm functions, horn goes off, and it re-sets when I put the key in the drivers door. It will not re-set using the ignition key in the ignition.
Now the questions;
Is it possible I have somehow reprogrammed the CCM to be expecting a different resister value? When this started happening, I thought it was a loose battery cable, and I turned the key many times fairly rapidly, and also was trying to tighten the battery connections.
Is it possible to reprogram the CCM, or is it possible it's just shot? I've though about bypassing the ignition switch resister reader by adding the other 14 resister values (one at a time).
I really don't want to tow this down to the dealer to get the CCM reprogrammed or replaced, are there any other ways to reprogram?
Any other suggestions?

 

I would expect if it was a problem with the resistor or VATS, that you would have CCM DTC's (1994's FSM 8D-6).

Also, considering the key in the door will disable the alarm (and the key does not insert far enough to have the resistor come into play), I would guess (not sure though) that the key in the ignition to disable the alarm does not go through the VATS system either, and thereby should disable the alarm. Unless, the problem is unrelated to the VATS and instead related to some connection or power problem also run through the ignition switch.

Have you 'Displayed CCM DTC's' - Diagnostic mode 1.1 (FSM 8D)?

Have you 'Displayed CCM Data - Diagnostic mode 1.2 (FSM 8D)?

Of help might be Data ID Number 06 & 07 & 08 (PASS-Key A/D Counts & Ignition Voltage and Switched Battery Voltage.

Have you used the 'Displayed CCM Inputs Status - Diagnostic mode 1.3 (FSM 8D)?

A couple of 'inputs status' input ID numbers which might help are:

'01' PASS-key Fuel, where a code of 1=enabled
'06' (B)Key in Ignition, where a code of 1=closed

Be sure to read NOTES (B) to understand the 'key in ignition' code.

Have you tried the 'Cycle CCM Outputs (diagnostic mode 1.4)?

One helpful Output ID Number might be 12 (B) Starter Enable Relay (remember to read the NOTES 'B').

 

No it can not be reprogrammed.


Get a VATS interrogator.

 

Ran the scanner and no DTC's, that's one reason I thought VATS was possibly ok. Guess I need to find the time to run the diagnostic modes per the MM as you suggest. Bummer.