Yes i have read Bill C. write up. It was very good and I am working off that for now.

I am trying to help out a friend of mine track down the issues with his 99 c5. I will give you a brief run down.

This car is clean. No accidents with 40k miles. On a 200 mile trip the passenger side window stopped working. We realized the power lock was not working in combination. There is no power to the passenger side door at all.

The car comes up with reduced power and all the gauges go out. Fuel is on E. The temp is maxed out ect...

Here are the codes I pulled from the on board DIC.

10-PCM P1626 HC

28-TCS U1302 HC
28-TCS U1016 HC

40-BCM U1255 HC
40-BCM U1016 HC
40-BCM U1096 HC

58-SDM U1301 H

60-IPC U1255H
U1016H
U1040H
U1064H
U1176H
U1088H

80-RADIO U1096H
U1016H
U1040H
U1064H

99 HVAC U1064H
U1096H
U1160H
U1255H

AO-LDDCM U1064H
U1016H

A1 RDCM No Comm.- I think this is the root of all problems. Once this code sets everything goes bad.

BO RFA U1255H
U1096H
U1064H
U1016H

I cleared all codes out and they came back. I cleaned the grounds by the battery and opposite side in engine compartment and put some dielectrical grease on them to ensure a good connection. I also cleaned off the ground that is inside the wheel well on the rear drivers side.

I know the grounds on the c5 are respondsible for the majority of "electrical grimlins" so i started there. Besides these three grounds, Can anyone else help? Got any ideas why the power to the door is no longer there or why the cluster has gone nuts? why all the codes? This car is immaculate! No rough play accidents or anything. Clean Clean Clean.

I alson checked the fuses with no luck. is there a relay that can cause all of this?

The problem was all of the sudden and is intermitten. everything starts working again when the car is shut off and restarted except power to the passenger door. "For a short period anyway"

Thanks for any input!

 

I agree. Sounds like the serial data buss is shorting out.

 

YEP,, Dead ringer for a corrupted serial buss!!