Just going to try one last time, so it is still no bussing. As the weather gets hotter, it no busses even when the truck is cold. It just did it today after letting it idle for like 2 minutes. It started up again after 15 minutes of waiting. It's 98 degrees outside.

When it was around 60 degrees at night I ran the truck for over 5 hours completely fine. No stopping. It ran like it just came off the assembly line. (I picked up a friend from the airport at like 10pm) The next day it was about 90 degrees, no bussed after 20 minutes of driving.

Anyone have any idea before I go and try to get another PCM which will run me $150 just to program it (the actual PCM is under warranty... but NAPA's PCM exchange people do not program it anymore so I have to go to a Dodge dealer to get it flashed.) unless anyone has another cheaper alternative to flashing a VIN into the PCM.

Oh also when it no bussed in my driveway today after ~2 minutes of idling, I put a code scanner on it because when it no busses a check engine light comes on, the code scanner would not communicate with the PCM. After the truck finally stopped no bussing and started, the code scanner communicated and no error codes showed...

All sensors related to 5V have been changed minus the sensor in the transmission.

Thanks guys any help would be appreciated.

 

I would suspect the PCM. Try hitting it with a hair dryer while it is working. (turn the engine off first) get it nice and toasty warm, and see if the error comes up.

 

I'll try that. Do you know of anyway to get another PCM flashed without having to spend an arm & a leg at a dealer?

 

You can try the pcm without flashing it.... so long as it is for your engine trans combo. The ABS, and Air Bag lites will stay on till you get it flashed though.

 

When you get the no bus error, do you still have 5 volts at the sensors? This sounds suspiciously like the phantom 5 volt regulator desoldering itself in the heat....somewhat known issue.

 

I haven't ever had a chance to power probe it. Everytime it no busses it's not at my house, it's in the middle of the road. It no bussed in my driveway today and started back up by the time I got to the garage and got the probe out. It hasn't no bussed once when we've actually been trying to troubleshoot it... which makes it an absolute nightmare.

Would opening up the pcm be able to see the desoldered regulator? Haven't done it yet because it's under warranty

Also another question, this PCM is remanned so it came with a code on what they fixed for it. The CAL # is 56040037AG 0037V. I'm not sure if that helps.

 

Keep a voltmeter in the truck I have a whole toolkit and 1.5 ton floorjack that stays in the truck.

You can't open the PCM without getting into a nice little mess. Not to mention warranty.

The first part of that calcode is the PCM's original part number. AG suffix means it was fairly late in the production run. Not sure what the 0037V is. That might even be the original PN from the stock computer that they cloned over.

 

Alright I'll try to get it to no bus again and to power probe it. I'll get back to you guys. Thank you for the help