Code Opinions

[Jughead]

On my way to the Texas Hill Country this weekend my 98 A4 died after I put it back in gear after stop. The "DIC told me to Remove Key and Wait 10 Seconds". I did and all worked fine. On the return home a few days later we stoped to eat and the passenger side control panel totally ceased to function. The window was down and would not operate...and the key fob would not set the alarm. The trunk lid would not open either by using the remote. I limped home with every code the DIC and instrument panel could throw at me...including "engine power reduced, service traction control, shocks inoperative, service engine soon"...I mean the works. The gauges bottomed out..AC quit and even the radio and wipers wouldn't work. I got home and found I had multiple codes... mostly the U type, one No Comm. and only one U had a C. I thinking battery so I pulled it and had it checked. It checked low so I replaced it. I cleared all the codes and started it again...same result. I still had a No Comm. with the LDCM and other codes. Since then I have checked the LDCM connectors in the A pillar and the ground on the drivers side. I even checked the ground in the battery well. No signs of corrosion and all connectors and grounds look great. I checked the connectors again...checking to see if I could get back any response from the door panel from "jiggling" the wires at the connectors...still nothing. I cleared all but the one current code and fired it up twice. I got the codes to repeat...they read;

99-HVAC U1160 H C
A0-LDCM NO COMM.
B0-RFA U1096H & U1064H

These three codes, the lack of driver's side control panel function and the total key fob failure (both) have remained constant through this whole adventure. They are leading me to suspect the left side door control module. I know the various grounds a C5 has can cause intermittent code and electrical issues but mine is constant in these specific areas. I'm about to remove the door panel and check for connector issues at the module or skinned or broken wires in the door. What do all of you think? After this last thing to try (door panel) I'm leaning toward buying a new module so all help and opinions would be greatly appreciated.

 

[4speed]

Try to "wiggle" the wires that go from the door to the cowl by squeezing/ pushing the rubber boot. If this helps, pull the boot back from the cowl, pull the wires out a little and un-plug then plug the connectors. It worked on my 01 when the door went dead.

 

[Joe Vette]

I had a similar problem on my "02" It was in the passenger door wiring by the door hinge through that "boot" Grounded wire.

 

[The Drakester]

Let me add to the fray. I haven't had those issues, but this happened yesterday and is a repeat from a while back. Here is what happened:
passing through about 4K in 2nd with 3/4 or so of throttle rear wheels lost some grip and then the DIC displayed low engine power, service traction control and "ding" "ding" - I limped to a parking lot at low power and turned off the engine. After several restarts, the check engine light went out and all was normal. relevant code was C1278 TCS Temporarily Inhibited By PCM.

While this does not happen all the time, it has happened twice now and the environment existing when it does (semi-hard acceleration) make it a bit dangerous (like pulling into traffic would not be a good time for the engine to decide to go to low power!) Anyone with thoughts on this?

 

[Jughead]

I wiggled the wires both times I pulled the boot back to remove the connectors for inspection. I also unplugged the connectors and inspected them...twice...no issues or luck after either time.

 

[DRTH VTR]

99-HVAC U1160 H C
A0-LDCM NO COMM.
B0-RFA U1096H & U1064H

The HVAC U1160 H C is a current code. Here is a thread that might be of some help. I hope that c4c5 specialist will see this thread as well.

http://corvetteactioncenter.com/forums/showthread.php?t=80105&page=2&highlight=U1160

 

[Jughead]

Fixed !!! All functions and no codes!

I pulled the door panel and started "jiggling" wires while holding buttons for function...nothing. I then started pulling connectors in the door while pushing buttons. As I started to move the center connector on the LDCM and I felt something move and heard a "click" as the connector slid in place. It was loose!!! Gotcha!!! . All buttons functioned. While I was in there I pulled and cleaned all connectors...just in case.

I took a test run and checked for codes. Nada!!!.

Everthing is normal. A couple of good things came from this experience...I learned a lot about the electrical system of the C5 I've had for only two weeks and now that I have the door panel off I will paint the speaker cover that has a stain.

Thanks guys!

 

[The Drakester]

You got yours fixed Horray! Any ideas on mine :-(

 

[Jughead]

Everything I have researched led me to understand if you have occasional performance issues, DIC messages and codes...start looking for battery issues or corroded body grounds. The key is if they are intermittant. Since mine was sudden and constant with communication issues I decided the player was the LDCM. It never went away. I was right and extremely lucky it was not the module itself. Have you run the DIC code sequence yet? Check those codes to see if there are issues that lead to the DIC messages you get. I learned the hard way that one such code issue can have a cascading effect that will eventually lead to loss of engine power, ride control, ABS and traction control issues. I was told that if you have a series of historic communication ( U type) DIC codes it generally is not a massive component failure. It happened to me. Maybe you will get lucky too.

 

[The Drakester]

Thanks, Jug. I'm going to see if I can force occurrence and do some various break traction exercises with TC on to see what happens. Battery is only a couple of years old and tests good. I'll check out the grounds - though I don't expect corrosion - garage kept and summer driven. I don't take it out if it looks like rain (although the wipers do work ;-)