25/11/2021 · 2003 dodge ram 1500 alternator problems. 2L 5. While driving, the truck is okay. 9L 8. 518 complaints. 3L V8. I was wondering if anybody can give me the proper diagnosis steps to ensure that the PCM is actually the problem and not something else Dodge Ram 2500/3500 5. Â The first thing to check in any The most common source of ECM failure is in one of the wiring harnesses. 9L V10 8.