g1teg

Ok I have read and followed a lot of the various threads on this. Cranks, no spark or fuel. No bus on dash, P1694 in codes.

I have no 5v ref (0.009V). Pin 3 and 11 at the DLC have ~~2.38V. with key in run. Key off - batt disconnected 60 ohm across those (jumps to 120 when I remove the gauge cluster)

I changed the CPS with a Mopar unit. No difference. I've unplugged basically every single sensor I can find, no difference.

Grounds and power to the PCM all look good. I refreshed all grounds in the engine bay. No fuses blown.


Jeep was running, only thing I can think of that I did was a bit of welding without disconnecting the ground terminal... All these symptoms point to bad PCM?

agreen

Yeah usually if there's no 5v ref, you have a bad ECU.

I will say I had a situation where I found some melted wires in the harness that was dragging down the 5v ref. I had to cut the 5v wires close to the ECU one by one until it came back. That one was a weird situation, and isn't likely. Still possible though.

You're on the right track. Nicely done.