More questions on the DCM

[jox99]

Last week I purchased a 99 Converrtible. My first Vette in 25 years. Man, have things changed! The drivers side door electrical is non-functional. The owner I purchased the car from stated that it died suddenly and all functions stopped working. The dealer told him the door control module was defective. I have read the various threads on this subject, but I need help on the wiring color codes and functions. I don't think that all relays would have died at once??? I am thinking maybe the connector or wiring harness has an open in it. Could someone post the harness make-up functions and color codes. I have a manual on the way, but I would like to get started. Any help, pointers or sugestions would be a great help.

 

[Toms007]

First off, Welcome to CAC. You'll find there are lots of very helpful folks here....unfortunately I'm not one of those with buckets full of knowledge. I can't help you much with your problem. But I will have to say that I agree with you in that I doubt all the relays went out at once. I believe that you are on the right track.

 

[c4c5specialist]

Hi there,

Lets be clear, your DCM would not fry all at once unless you had a massive voltage surge.

What you need to do is get the diagnostic trouble codes using the link at the top of this forum.

Please write them all down and VERY SPECIFIC as to what module the codes came from.

If you have a NO COMM, write it down, its just as important.

We can then assist further.

Allthebest, c4c5

 

[jox99]

C4-C5, et al; This afternoon, I went into the DIC to see what I could see. Lots of history codes for all the different sub groups. Only one had a H C listed. It was under HVAC and it was U1160. The A-0 LDCM showed "No Com" (no associated code). The A-1 RDCM showed B2253, B2283, B2285, U1255, U1064, U1016, and U1096. The A6 SCM showed U1255,U1016, U1064, and U1300. The B0-RFA showed U1096, U1064, and U1016. If I could type better, I'd list the associated fault names, but I would be here all night. There are a lot of history codes not listed here. 2 in the PCM group. Many in TCS and a few in BCM and IPC. All are history listings.
So, is it best to clear all the codes and then start up the car and see what faults show, or work from the existing data listings? Is there a way to single step through the codes? At 3 seconds apiece, I had to go through the entire listing several times to copy down this info. On to step two.

 

[c4c5specialist]

HI there,
Your "NO COMM" is the reason your left door doesnt work.

Any U CODES that are HISTORY, you can disregard.

The first thing to do in a problem like this is to go to the inner hinge pillar on that left side. Under the dash, facing the outside where the hinges are, is a square black plastic plug. Pull that out and look at the 2 electrical connectors there.

Separate them and look very closely at the terminals to see if any of them are burnt or opened up so that there is a connection problem.

Let us know what you find.

Allthebest, c4c5

 

[jox99]

Furtherr update:

This afternoon, I checked the connectors. No corrosion (this has been an Arizona car for the last six years). No loose connections or bare wires. I wiggled both wire bundles and no response. The stereo works on the drivers side as does the door light. The seat controls work when using the controls on the seat. The Pass. door window, lock, and keyless entry work. I looked at the circuit board in the DCM and could see no evidence of smoked components. (Then, again I did not expect to find any). So, I am at a loss. The three orange wires have power to them. I don't have the wiring diagram, so I can't ohm out the rest of the harness. Help!!

 

[c4c5specialist]

HI there,
If you have check the female terminals and your are not seeing any open terminals, its most likely a left door control module.

Allthebest, c4c5

 

[PreacherNutshot]

Oh, and when it turns out to be the left DCM, send C4C5 some cookies. I've lost count of the number of folks he's helped out.