Bad PCM? - Diesel Forum

mwachel · 01-22-2006, 11:49 AM

Hi all...

My 2005 X PSD 4x4 EB with 22k miles has some gremlins running around in it. List of OCCASIONAL problems. Also, keep in mind these don't start or stop when the truck is running...they will ONLY begin or end when the truck is re-started.

-key fob won't lock the truck (usually inop from 1 restart to 1 day).

-AC controls go dead..auto climate control. Never dies or starts working when the truck is running...ONLY when restarted. (usually lasts less than a day). The dealer actually saw this one and says it is the control unit and are going to replace it. This has only died 3 times in 4 months.

-when the truck is running... open any of the doors and the truck doesn't beep (one quick beep) to tell you that a door is open. It works about 50% of the time.

The dealer just shrugs and says there isn't much they can do. They are woking on the AC and he has witnessed the door chime but doesn't know what to do.

Sorry the long post but this is driving me nuts!!!! COULD THIS BE A BAD PCM? WOULD A REFLASH FIX IT? HELP!!

Casey_1 · 01-22-2006, 03:22 PM

No, it couldn't be a bad PCM because none of those things are controlled by the PCM. The PCM controls the engine and transmission, and nothing else.

rcdallas · 01-22-2006, 03:27 PM

Perhaps a faulty relay or two is what comes to my mind. You don't have your location listed, is it near a large body of salt-water by any chance? I ask because salt loves electrical componets.

mwachel · 01-22-2006, 04:29 PM

No salt water here in Las Vegas.

Could a relay control all of these components?

Casey_1 · 01-22-2006, 05:17 PM

No, a relay can't control all those functions, but there are body computers that do control all of those. Unfortunately I don't have detail on those. The symptoms sound like a grounding issue. Those are often intermittent.

budman451 · 01-22-2006, 06:40 PM

All those components are linked together via the Vehicle Security Module (VSM), which is located in the center of the dash, behind the radio/AC controls.

Check your windshield for leaks coming from the sealer used to glue it in the body. Water has been known to leak through the glue, and onto the VSM, causing it to fail. You will most likely need to replace the module.