Jan 22, 2020
In Chrysler ecu repair
I picked up a 1997 Ram with a 5.9 and 46RE. It looks like the PCM might be dead. I found Keenans Youtube video about opening a JTEC PCM and realized I was on the right track looking for a voltage protection diode. However, my PCM doesn't exibit such a failure. When I turn the key on I'm getting voltage at the two 5v supplies (4.5 on one and 3.5 on the other) I don't get any response from a scan tool or the check engine light when doing a key self test. No lamps from the PCM appear to work, and the ASD and FUEL pump relays aren't getting their ground. I removed the PCM and supplied bench power, wired up a DLC between the PCM SCI TX/RX and a ELM327 scanner and am unable to get a connection. I then wired a small bulb up to the MIL driver pin and get nothing. I checked this pcb over pretty closely and can't see any signs of poor solder joints or broken traces. Where should I go next? I feel like the simple, few skills needed, easy to diagnose failures are accounted for.