Ruralmedic

I had my ECM recalibrated two weeks ago to enable pin #20 on the ECM plug for exhaust brake operation. Now I have a few problems. I have keyless entry, and now the security illumination (dome ights) stay on while driving. The electric door locks won't work while the engine is running, but will when it's off. <br><br>Today after I started it up, I could smell something burning, and it turned out to be the connector plug under the drivers seat. The pink wire had melted from the connector. I've since disconnected it, the truck runs fine, but I can't use the seatbelts now, they're locked retracted. <br><br>The engine also has a skip, or miss at idle, that wasn't there before the calibration. Any ideas as to what may have happened after, or because of the service calibration?

DF5152

i now some people just can do to much with computers and that some mechanics are that because they cant do anything else but how hard is it to reflash and ecm? I've been working with computers for years and have never had a problem reflashing a bios whats the deal any techies out there that can explain.<br><br>on the subject of ur truck sorry to hear ur haveing problems now hopefully they can get it straightend out.

Ruralmedic

Well, I've got it fixed, I don't know if it was related to the ECM service calibration or not, but the problem started right after that was done.<br><br>Cummins said that this would have nothing to do with the ECM. So, I researched the electrical system, reading just about every post here that had anything remotely to do with it. <br><br>The culprit must have been the Seatbelt Control Timer Module(SCTM) that caused a short. The local dealer did not have one in stock, so I ordered one. I still had the problem with the dome lights and key chime. So while waiting for a new SCTM, I removed the lower dash panel, and found another timer module, just below and to the right of the steering column. I unplugged and removed it. I opened it up, sprayed the printed circuit board with contact cleaner, put it all back together, and bingo, the dome lights, key chime, and door locks now work as they should.<br><br>Today I received the new SCTM for $118. However, the wiring harness from the door sill to the connector under the seat, which carries a DC P/N, is already obselete. This system which uses electric solenoids to lock the seat belts, where they retract into the seat backs, is no longer used. So rather than search salvage yards for a 10 pin plug, I wired up some by-pass jumpers for the melted ones, using the original plug. Installed the new SCTM, and the seatbelts now work as they should! Whew, I'm much happier now. Although the miss at idle is still there.