2001 Jeep Cherokee 4.0L 4X4

Ok, so recently started to work on this XJ I bought a couple years ago. Jeep sat in my garage and started with a simple head gasket repair. While doing this, it sat for about 3 months due to extreme laziness to finally complete it. Before doing the head gasket, it ran but had a no can bus issue and no communication with the OBD2. Now since the repair is back together I’m getting a zero communication, no spark, no fuel pump activation, and have verified that ever connector has been installed.

I have been testing everything imaginable, but haven’t seemed to track down the issue. I’d like to get it back to running or at least figure out the OBD2 communication then work on tracing everything else down.

When I test the power going into the PDC I have 12.1V. Check power to the ASD and Fuel Pump Relay I have 12.1. Verify the fuel pump is working when jumping the relay and check the pressure reading. Then check power at the fuses and I’m getting 6.7V. This leads me to believe I have a possible bad ground, even though I have verified all grounds and resistance.

When I check the OBD2 port according to the test procedures, I have good ground and power, but my CAN+ and CAN- is reading 5.8V which seems high.


Honestly, I’m just looking for other possible ideas anyone else is having. I’m slowly learning towards a bad PCM, but wanna see what everyone else may think.

What is the voltage of your battery?

11.9v and have even hooked up my charger to verify it wasn’t a battery issue

Bump

11.9V at battery is totally unsatisfactory. It should hold well over 12V, preferable around 12.5

Do you have a parasitic current draw ? (use a test light)

I would bank on either missing ground, bad connector, or some sort of parasitic current draw that should not be there