I decided to compile the previous thread and start fresh, especially since I'm right back where I started...

Original issue: Driver's side door controls quit working and aftermarket radio show an error on the display regarding a wiring issue. This makes me think that the door is not getting power to the right places for the windows and locks and the speaker amp (aftermarket Alpine unit that replaces the Bose unit) is dead, hence the error.

It started, which may be coincidental, when I had the car painted and the door panels were removed during the process. When I picked up the car, the aforementioned issues were present but it took a few days to realize it. After sitting for at least overnight, the door controls usually work. The windows function, the doors lock, etc. The radio still does not work. If I start the car, the driver's seat moves forward automatically as expected and I back out of the garage. Then the driver's door controls quit and the passenger window rolls rolls down by itself. I have to raise it using the passenger side switch. This problem has not affected the passenger door controls.

Troubleshooting done so far but not necessarily in this order: Pulled DIC codes (all related to LDCM), replaced LDCM, replaced BCM, replaced door control switch panel, checked fuses for power, disconnected (I think, as it has six wires) door amp to make sure it wasn't shorted out, removed and replaced star connector at four wire connector beside BCM to isolate the problem, and checked and tightened connectors in accordion at door hinge. The battery is good and cranks the car well hot or dead cold. My multi-meter shows both power wires to be hot on the door side of the connector. I don't know what else to check or how to measure it if I did.

After a bunch of work and some money spent, the situation has not changed at all. I can lock/unlock the passenger door from the driver's side but that's about it. This problem surely seems to be with the door itself but I've had the door panel off multiple times and can't find anything. But what am I missing? Sitting in the garage after being off for some time it usually works. Cranking the car and moving is what seems to cause it to fail or results in failure.

Can we continue now? I really want to get my car fixed. I can't even use a drive-thru teller machine or buy a drink at McDonald's without parking and going inside now. It's really aggravating. Thanks for your help.

 

If I am correct when you unplugged the Black C201 connector in the A-pillar the problem went away. If so---

That would say it is something in the door or something funky in that connection. I think we can discount the BCM being the issue since you replaced it.

To affect the right door from the drivers side the interface HAS TO BE DONE via the serial bus.

This is just a crazy issue but there IS A REASON.


Mr. Sam

 

Tonight we decided to drive the Vette to a dinner. I got in the car and everything worked until I moved the seat up and started moving. The lights on the driver's side door switch pad went out and the passenger window dropped. The door has been dead since. I'm not sure how to proceed.

 

I don't think moving the seat is related. I want you to unplug C201 and inspect both male and female sides. If you fix anything plug it back in and see what happens. If not, leave it unplugged and see if it again eliminates your issue.


Mr. Sam

 

I read electrical gremlins 1 and I don't think anybody said anything about cleaning the grounds at the bottom of the A pillars behind the kick panels. Then if you can check around the clutch pedal for a bare wire. It seems when you start to move the car the door goes dead.

Bigdad

 

I would think that bad grounds would prevent it form working at all, and it does work occasionally after sitting overnight or for a few days. As I have not been up under the dash for anything, I would assume that all the wiring is still in the factory wrapping/covers and safe from harm. However, I will take a peek at that if my arthritis will let me. Too many old sports injuries...

 

For some things, our cars are not meant to be worked on... Particularly under the dash.

 

New development/observation today...

We decided to take it out for a drive today. I got in and mashed the clutch, turned the key and fired it up. The seat didn't move up automatically, which was nothing unusual. Sometimes it works and sometimes I have to hit the button on the driver's door controls. Instead of moving the seat up, I checked the driver's window. It worked. Over and over, it worked. The locks worked. Everything worked just like nothing was ever wrong.

Then I pressed the button to move the seat up. The seat moved up, the driver's door controls quit and the passenger window rolled down. After that, nothing worked for the rest of the day. Keep in mind that I had not put it in gear yet. I was just sitting in the garage with the engine idling and the tranny in neutral.

What does the seat have to do with the driver's door controls?

 

The seat has the MEMORY MODULE in it. Have you tried to disconnect the memory module and or disconnecting the seat? See how that plays into the game.

 

Where would I find the module? Do I have to remove the seat to disconnect it or the seat connector itself?

 

Its the BLACK module way down below everything with all the connectors on it.



BC

 

Thanks, Bill. I'll get on that first chance I get.

 

That matches up with the fact that if you unplugged the driver door connector the problem went away. That would terminate the SCM interface with the door controls.

I NEVER would have thought the SCM was at the root of this.


Mr. Sam

 

Is there an easier way to unplug the whole seat without taking it out? Is there a more accessible connector somewhere? If that fixes it, then I can remove the seat to make the necessary repairs. I just don't want to have to take the seat out twice.

 

Maybe you could try the passenger footwell fuse box.
fuse #4 driver's seat control module
circuit breaker #35 driver power seat.

Bigdad

 

You can set the seat where you want it and then reach up under the seat and disconnect the connector that plugs the seat into the car harness.

 

That's what I wanted to hear. I need to go look for it.

 

Where is the cable that I need to disconnect? From Bill's picture, I can see the cable but I need to know where to look for it with the seat still in place. Will removing the fuse be just as effective?

 

The wire for the seat comes out from a SLOT in the carpet under the seat. Just feel around on the carpet near the seat rail closest to the door and find the wire harness. That farness connects to a SIX WIRE CONNECTOR/

 

Before disconnecting stuff, I made sure that everything worked as I did previously. Then I turned off the automatic seat option from the dash controls on the DIC. After that, everything worked fine and we drove it to an event about an hour from home. No problems at all until I restarted the car after it sat for a couple of hours. The doors unlocked from the fob but that was it. Dead again. I'll unplug the seat harness and try again.