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!

 

Looks like you either have a grounds problem or your BCM is bad. My guess is that there is corrosion issues on your grounds.

http://www.stengel.net/diccodes.htm <--- Majority of the codes

10-PCM P1626 HC <- Theft Deterrent System Fuel Enable Circuit

28-TCS U1302 HC
28-TCS U1016 HC <- Loss of Communications with PCM (Usually a grounding problem)

40-BCM U1255 HC <- Generic Loss Communications (Also usually from grounding problems)
40-BCM U1016 HC <- Loss of Communications with PCM
40-BCM U1096 HC <- Loss of Communications with IPC

 

All of the codes with a "H" are history.

Start by clearing all of the codes and the restart the car to which ones come back.

Shake your door accordians. The rubber sleeves in the door opening and see if that causes any problems.

I'll bet you have a short in one of the accordian wire looms.

 

BlownVette 2001 is correct!!!!

This WILL work and same you lots of money....Send us an update after you try this....

Author : Bill Curlee
Before you get too deep in cash flow, try this. Grab the rubber accordion tube between the door frame and the door and while your pressing the window switch, shake the wiring harnesses inside that rubber tube. See if that will cause the door to start working again. Let me know how you make out.

Here is the deal. There are two plugs inside the door jam. You need to remove the rubber boot on both ends (it easily pops out) and pull on the wiring harnesses to fish the connectors out of the body. It will look some thing like this:



Look at the connectors and see if you see any bare wires like this:



If so pull the insulation back down and use some electrical tape to isolate the bare wire. You can also use some liquid electrical tape to insulate it. Ant boat store or hard ware store should have it.

let me know how you make out,

Oh,,by the way,,, the drivers side is most likely just like that one. I would do that one too!:thumbs:

BC[/QUOTE]

 

DO NOT CLEAR THE CODES, or you can be fooled for up to 50 miles and think the problem is fixed, only clear after you have found the trouble. Do not replace any modules until you have found a bad one, I bet you have a poor or damaged connection. This was the first car that gm used this new style communacation system in. All of the modules need to talk to one another in a circle. I would start with the passenger door that you have issues with. Unplug each module one by one (one at a time) until the gauges come back on, yes the door switch is a module. The modules talk in a circle with information called cereal data. When the problem module is found look at the wiring that leads to it, for breaks in wires, you many have to test the wires, unplug the module's or you can damage them for wire testing. Look at the plug for the module in the passenger side kick panel area and look for poor connections, gm had problems in this area, and the opening and closing of the doors loosen the plugs. The codes will stay but the gauges will function with the module that is causing issues unplugged. When you are done you can clear codes by clearing DIC and going to the clear emtpy DIC on the options button and hold option button down (no info can be displayed on DIC) and press fuel button four times and you can clear codes from here.

 

Clearing the codes eliminates the ones in history and lets the "OP" concentrate on the active problem.

Maybe he will get some other codes and maybe not. None the less he needs to start somewhere.

I've always cleared the DIC and concentrated on the active codes when trying to resolve electrical problems and it has always worked for me. I would rather tackle one problem at a time than to take on multiple ones.

Just my methodolgy.

 

Okay, I'm just a Gm master tech and been in the auto repair cusiness for 21 years your right, clear the codes, but the codes will be back in 50 miles DA.

 

No one saying some of the codes won't come back, but these cars tend to get a lot of other codes that are not imporatnt that build up in the system and by eliminating all of them you isolate the current issues.

I'm sure you do this all of the time when you're working on issues, process of elimination.

 

very good advice here...I would keep it simple to start, in other words check the battery and alternator first. C5s as you already know can have some strange electrical issues and low voltage can cause many of your issues. I would test the alternator with a dmm (digital multi-meter) to make sure you are making enough power, start the car and turn on the ac, radio etc. You want an electrical load, the meter should show around 13 -14 volts. You can measure this at the battery as well as the alternator. You might wanna have the battery load tested at an autoparts store.

 

I have/had the same problem with my 99FRC.
Now it's just both windows intermittently acting up, no more DIC Christmas tree.
I deleted all the ground blocks and soldiered all the grounds together like GM did on the C6.
I also deleted the door jam connectors and used shrink crimp connectors on all the wires.

Windows still don't work all the time (mostly never) pisses me off.

I think I'm going to have a stealership diagnose the problem.

 

Could be bad motors or door control modules. How often do you use them ?

I was getting a 2254 or 2253, I think ? can't reallt remember and it turned out to be a bad drivers door conrtol module that I traced down with the Tech2.

I picked up a used one off of fleabay and all was good.

 

Motors are good (powered them with the battery)

The windows usually go down, but wouldn't come back up the same day. Seems like something has to reset or cool down, pisses me off (did I already say that)

Yea, I agree with the need for tech 2.

Sorry for the hijack, but I think we have the same problem.