Pcm voltage issues

[Mopar1973Man]

 

 

Edited January 19, 2021 by Mopar1973Man

[dave110]

11 hours ago, dripley said:

be patient my friend. not the first change of government either of us have seen. Maybe these folks can sit at the table and actually talk. tryng to keep an open mind.

I can appreciate keeping an open mind. The way this next bunch likes to spend money we'll be keeping an open wallet too 

[Sugmadique]

Lmao, holy crap this thread went off the rails while I was gone. Anyway I had some time to work on the cummins this weekend and I brought my snapon Verus home to do some diag work. When I checked the live data I had crank signal and cam sensor signal at the ECM. The engine speed matched what the tach was reading so went into the PCM with the scan tool and there is no engine speed/ crank reference signal at the PCM. I had the alternator fail and take out my PCM before and have already replaced the PCM and added an inline fuse to protect it from that happening again. I checked the gray/black wire at C1 pin 8 and there was only 200-300 millivolts instead of the 5ish expected. I attempted to perform a voltage drop test but the voltage readings at the ECM pin 45 was the same. I checked to see if the wire had shorted to ground by doing a resistance test to ground and with both connectors disconnected I probed both connectors and tested resistance to ground and had a reading of infinite ohms. I think I have a bad ECM unless there’s something I could have missed.  I already did the w-t ground mod and replaced all my battery cable ends and terminals with the military style terminals. I’m using optima batteries that are old but tested fine with my Autel battery tester. 

[Mopar1973Man]

The only thing I can say is contact a ECM/PCM rebuilder and see about having them tested quickly.