2016 Coronado pdm issues.

I have a 2016 freightliner Coronado 122SD. Isx15

Power to pdm “under passenger side of the dash” with keyswitch off if you put a test light from the battery post to the ignition post the fuel pump turns on and the gauges cycle. You can also jump from the iso post to ign and the gauges will cycle. Thetruck was going down the road with a load and died on the driver. I jumped the two posts to get the truck home. I’m running out of options with this truck.

Has anyone ran into pdm issues? Is there a common short to ground that I’m missing?

I feel as if it’s a internal short in the pdm or it’sgetting back fed by a different short. If you put the test light on the battery post and put the probe on ignition fuses and some others the light will alsolight up and cycle the gauges/ fuel pump-provide ignition, and complete the circuit.

Any help would be great

 

I’ve ran into that before, it’s just the fact that everything is grounded when it shouldn’t be. I’ve had the freightliners throw me some curve balls before, but this one is odd. I’d like to get it done soon because now I have a cascadia loosing multiplexed devices and gauges. Intermittently.