No user serviceable parts inside......(PCM)

I think you are making this more complicated than it really needs to be.

Circuit 142 is indeed grounded by the PCM. That is a sense circuit there to verify power on the output side of the ASD relay. It will also go to ground thru the O2 sensor heater circuits. So, what you are finding, is perfectly normal.

You need to find out if you are getting POWER out of the ASD relay. With Key on, engine off, you will have power at pin 30 (from the battery, always hot) and pin 86 (from the ignition, only with key in on, or start position.) Pin 85 goes to the PCM, and is the control side of the relay circuit. That wire should ground for three seconds or so when the key is turned on, or the PCM sees the engine turning, otherwise, it should be open.

 

I worked that backwards. I had thought that Circuit 142 was powered. I wrongly assumed that since 87 on the ASD relay is the high current output, that it would be open, and not grounded.
I will re-assemble what I have taken apart and work the other way.

 

I solved this problem. The PCM/ECU/ECM computer failed causing circuit 142 to remain grounded at all times. I swapped out the PCM with my daily driver and the truck started right up.



I know this is an old thread. Just doing my civic duty and reporting that the problem is solved and how.