03911TT

My 2009 C4S Cab's PCM unit has a mind of its own and turns itself off and back on while operating (sometimes 5+ times in a 15 minute drive). I've had the entire PCM headunit replaced under warranty and I'm headed back to the dealer for them look at it again, but they are not sure what to do next. I searched our forum, but couldn't uncover the "missing link" as to what might be the issue, any thoughts?

Bijan

Intermittent power supply ? In plugs, ignition switch, fuse box etc ?

Mumbles

Sounds like a loose connection. I'd check all contacts and ground wire. Maybe there's a bad connector at the head unit ?

DallasDave

I'm going through the very same issue right now. Exactly as you described. My dealer updated the software without success. A replacement unit is now on order. Concerned that you are still having problems after replacement.

Another issue that is a problem for me is wondering radio stations and intermittent cell phone interruptions.

Seems unreal with today's technology.

Dave

Marshal_Mercer

How high is your battery's voltage after resting over night? 12.6 volts is good. Low voltage gives ECUs fits.
Marshal

markiii

I had exactly the same issues

once i replaced the navigation disc with a new copy its been fine ever since, it seems that if the disc cannot be read the unit just keeps trying, and trying and trying until the drive overheats, which completely foxes the PCM and causes a reboot.

03911TT

Thanks for all the input. Seems like a few others have the same issue, I will update if/when we get a resolution.

LewisB

Mind of its own...turning on and off at will...unpredctable...causing trouble.....sounds like my ex-girlfriend. Who still wants to be my girlfriend. Where do I seek warranty coverage????