PCM malfunction

ninelevenick · 02-03-2013, 11:13 AM

Has anyone experienced a problem with your PCM? My '06 has the Bose system with the nav, cd changer, external amp, etc. After having driven for about fifteen minutes, the PCM will start to do strange things. It usually shuts off, turns on again, perhaps work momentarily, shut off, speakers make a pop sound, and then it becomes unusable until the vehicle is shut off for a while. Sometimes it will display a system error message informing me that the nav, cd changer, amplifier, and whatever else is tied to the MOST loop is unavailable. I pulled the head unit last night to check the connections. Nothing changed as I wriggled things a little. I did notice that a sharp thump on the head unit resulted in a one to two second hiccup where the music turned off. The display may have turned off too, but I do not recall. I thumped the head unit to simulate road jarring as it seemed like the unit would act up when the vehicle went over bumps. However, the sytem would continue normally after each sharp thump. I do not know if the error code relates to the hiccup episodes or not. I have read that the amplifier has been a well known culprit, but I lose all PCM functions when things malfunction, not just sound.

So, there it is. I am very frustrated. I am slowly investigating the issue, but any more information and/or advice would be appreciated.

Nostril Cheese · 02-12-2013, 12:27 AM

No highs, No lows, must be Bose.

I've seen this a couple times, It can be as simple as a loose connector in the steering wheel, or it can be something more complex. You really cant know more without hooking it up to the PIWIS. I dont suggest you start taking out the components without the PIWIS either. You can cause more trouble than you already have.

ninelevenick · 04-14-2013, 01:04 AM

PCM issue solved! I sent my head unit to the Becker repair facility in New Jersey. Turns out that the fiber optic control module was faulty, and the tech said that it was also related to the power supply. this explains why jarring bumps could turn off the unit. Lastly, the built in CD player was not working correctly either. It wasn't cheap, but at least my wife can enjoy her tunes again. A happy wife is a happy husband.