Ok here’s the latest:
I dropped the truck off 9/3. They’ve had it everyday since. I figured out right there in the service bay with the adviser watching and OBDII dongle installed, that I could make the truck replicate the issue by leaving it in park, and applying the slightest possible amount of throttle input. Just enough to bring it up a couple hundred RPM above idle. Holding my throttle input (foot) rock steady, eventually the idle would start to oscillate, cycling by dipping below 500 rpm, then jumped up to 900/1000ish then back. Compressor would kick off and on. Blower motor would cut out and come back on 20 seconds later. Holding my foot just barely on the gas, the oscillation would vary some, generally getting worse, but after 2-3 mins the truck completely stalled out. We were all pretty shocked, but you couldn’t ask for a better scenario. Adviser had her tablet right there recording codes while it was oscillating and when it died. Obviously tripped a few codes, the odd one being blower motor overcurrent. Into the shop she went. They started with a pcm flash for an unrelated issue. Tried to tell me it was fixed - failed, weak attempt. Then they started troubleshooting with star center involvement . This led to R & R (remove & replace) of the CAM phaser. This did smooth out the idle significantly btw. So, side note, if you’ve noticed your truck idles relatively rough since the time it was new have your dealer check for random misfire codes and the CAM phaser/target wheel. My bad CAM phaser was reporting up to a 36 degree delta. Did not fix original issue though. They moved on to blower motor overcurrent, eventually replacing the motor, module, and ringing out the harness (twice) - failed. Next up were signs of desperation, as they R & R’d the PCM - failed. Regional Chrysler engineer had been heavily involved by this point. Next up was R & R battery and alternator - failed. At this point they finally decided to record the trucks telemetry stream real time while it was acting up - great idea. Lo and behold, they found out there was a communication drop out happening with the PCM, yes, the new PCM. Then they told me there is a “history” of this throttle body back EMF’ing the PCM and damaging a portion of the board. Next, replace the throttle body and put yet another, unmolested PCM in it - problem solved! Hope this helps for those of you who have been driven nuts by our trucks doing this. There is very strong evidence this is a systemic issue. The 2021 loaner 1500 I had did the exact same thing btw.
