Helping a friend with her 2018 2500 4x4 gas tradesman edition. It lost all power while driving and not sure why but she replaced the BCM, PCU, TPS and ignition switch. It will not clear any of the codes and will start. run rough for about 5 seconds and shut down. The dealership near her house in Utah says they want no part of it. I'm not sure why she replaced all these parts to begin with and now it is a massive headache. Thanks in advance for any info.

 

You mention that it will not clear any of the codes. Do you have the list of codes? If so, please provide them. She's going to need to figure out what the truck does or does not have when it stalls. Has she measured the fuel pressure to make sure it's within specification? When it "lost all power while driving" was it like the battery was completely disconnected, or do you just mean the engine stalled but the lights on the instrument cluster still worked? What did she have to do to get it to restart after it "lost all power while driving?"

-Rod