I started having some electrical issues with the C5 Friday afternoon. The Pass window wouldn't work nor would the remote mirror or door lock. Saturday morning I checked the mini fuses that control them and they were both OK. I changed them anyway. After I got in the car and started it up I got all kind of messages on the Instrument cluster display screen. Telling me reduced engine power ABS, Check Gauges, U name it and it was there. I have a feeling that I must have shifted something around while fighting to put the cover back on the fuse box. I restarted the car and all the messages went away but still no passenger door controls. While driving the car around I noticed that the cooling fans were not working now and they were earlier.
Any suggestions what is going on? I'm going to check the plug-in on the door inside the rubber boot tonight and check all the plugs in to the PCM. I listed all the codes that the read out gave me. Most of them seem to be from when I got all the messages on the read out
Any help would be appreciated




RDCM
No communication

PCM P1626H

TCS U1301H

BCM U1255H
U10936H
U1016H

SDM U1301H

IPC U1016H
U1040H
U1064H
U1160H
U1176H
U1255H

RAIDO
B1016H
U1064H
U1096H
U1255H

HVAC
U1064H
U1096H
U1160H
U1255H

LDCM B2282H
B2286H
U1064H

IPC U1176H
U1160H
U1064H
U1040H
U1016H

RFA U1000H
U1064H
U1255H

 

A sticky at the top of the page should help you with some of those.

 

Thanks For that info. I'm cleaning grounds tonight.

 

what kind of battery do you have in your car?

If it is a stock delco, it could be the positive terminal corrosion where it basically rots the cable and post out of the battery.

Check it but put a bunch of rags around the battery before acid spills on all your wiring and computer.

 

The battery is an Optima. I'll check the connection though. I Haven’t had the car that long

 

Your problem will be solved by shaking the accordian hose between the door and the body.

I had the same issue 2 months ago. If this works all you have to do is expose the wire harnesses from inside the accordian tube and find where the wire is bare. Tape that area and reinstall the accordian hose and you're good to go.

I'm in Houston area as well. If you need help give me a call, I'll pm you my cell

 

This is a WELL DOCUMENTED and easy repair. The wire that has the insulation issue is the class 2 serial data wire for the door control modules. Depending on how and when it shorts and what it shorts to, will determine what is effected. When mine was shorted, the car wouldn't start, I also had door control issues and weird dash indications!!

Knowing that I had intermittent door issues that could be corrected by wiggling the accordion tube, led me to this easy repair. Here are some pictures to help you understand the issue.





Just POP the rubber accordion tube off the door frame and the door and allow it to hang on the wiring harnesses. They reinstall easily. Then fish the harness and connectors out of the pocket in the door frame.

Almost every C5 I have ever inspected has had this issue to some degree. The bare wire is a serial data wire so shorting the wire to ground will only effect digital data and functions of various modules.

I used liquid electrical tape to cover the bare wire then electrical tape to protect that. NO problems since i fixed it!

BC

 

Bill, Thanks to your tips once again this was the fix for David.

I talked him through your tips from my window issues and sounds like he's good to go now.

 

Thanks Bill and Frank.

Got the passenger door working and now it's just figuring out the cooling fans issue tonight.