Hey all-
I've been having some issues with some electronics components in my 2001 Coupe and was hoping to get some assistance. There have been issues with everything from the drivers side power seat, telescoping wheel, radio, Traction Control and even in starting the car from time to time.

I've done nothing aftermarket to the car except for swapping out the air filter. I pulled the diagnostic codes on the car for the first time today and came back with those that you see at the bottom of this post. I already looked up the description of the codes and input them below but was looking for any other decription people might be able to add.

I was hoping someone could give some color as to what might be causing some of these issues or any experiences people have had with fixing some of them personally. I noticed some corrosion on my main battery cable (positive) and will obviously start looking there. Thanks in advance for your input.

40-BCM
B0432 H - Rear Defogger Relay Circuit
B0503 H - RH DRL Relay Cicruit
B0508 H - LH DRL Relay Circuit
B2483 H - Backup Lamp Relay Circuit
B2528 H - Horn Relay Circuit
B2588 H - Column Lock/Unlock Drive (A)
B2593 H -

A0-LDCM
B2282 H - Battery #1 Fault DCM-LEFT
B2284 H - Battery #2 Fault DCM-LEFT
U1064 H - Loss Of Communication with DCM (No SOH Message Received - RFA

A1-RDCM
B2283 H - Battery #1 Fault DCM-RIGHT
B2285 H - Battery #2 Fault DCM-RIGHT
U1064 H - Loss Of Communication with DCM (No SOH Message Received - RFA

A6-SCM NO COMM.

B0-RFA
U1255 H - Serial Data Line Malfunction - RFA

 

a bad battery connection can cause all of your symptoms and it sounds like your cleaning and torquing the connections will be a great start. i think it is 10 ftlbs or so. (may be 11) don't forget to clear the codes after you are done.

 

DAMN! Clear ALL of those DTC and start out fresh. Then list what codes come back.
BC

 

Yo Zack!
I agree, codes could be who knows how old... or do they have dates associated with them? Now that you have them written down let's clear them out, do some burn outs, and then run them again and see what happens.

Now I have to go back to my cage in the C3 Forum.

Later C5s

 

I've cleared the codes and taken the car on a few short drives. The only code that has returned is:

A6-SCM NO COMM.

My seat, column and door locks still do not work. I seem to remember reading somewhere that the SCM controls the telescoping column so that would make sense and a read an article about a relay in the Door Control Module that seems like it may be the problem. Anyony have any suggestions on troubleshooting the SCM error above?

 

The NO COMM message means that the SCM is not communicating with the other computers on the network .... either the SCM lost power (Check in the Instrument Panel Fuse Block Fuse 4 (10 Amp) and Circuit Breaker 35 (20 Amp), or the wiring to the SCM has come unplugged (underside of driver's seat), or the SCM has failed. Most likely either electrical supply or wiring has come undone.

 

Thanks Black! It was just the number 4 fuse that was burned out. I could have sworn I checked it out before but apparently not. Seat and column are now working.

I still have issues with my drivers side door lock though. I wanted to check the fuse on that too but check out how the fuses are listed in the manual:

30 Right Door Control Module
31 Power Feed Door Right
32 Fuel Tank Door
33 Door Control Module Left

I scanned through while I still had everything undone and couldn't find the word "Left" at the beginning of the description. After I closed everything up I searched the PDF version and found it....but listed differently then the Right Door Module....pain in the rear!

Anyhow, my drivers side door lock is still not working. Any chance it is the RDCM? My window works find so I don't think it's that. I read a post elsewhere about a relay in the DCM burning out and causing this issue. Any suggestions on what this might be and the best way to fix it? The relay swap out looks difficult and I don't want to pay to swap out the whole module if necessary. Could it be something else I'm missing?

 

When you say the driver's door lock "isn't working" ..... can you lock/unlock it manually from inside with the handle ???? Can you lock/unlock it from outside with the key ???

If yes ... and your driver's window is working ... then I'm afraid it most likely is the LDCM (Left Door Control Module)

Here's a link to a thread that has an EXCELLENT write-up on how to fix the bad relay.

http://forums.corvetteforum.com/show....php?t=1606865

Get a buddy who's mechanical to come over ... provide him some pizza and beer and have at it .... it really isn't that difficult.

If you want to just replace the module ... for your 2001 .... part number 10342159 and list price is $294.50 ...... OUCH !!!!!

 

Yea, the manual lock mechanism works just fine. I can even use the key from the outside of the drivers door to luck/unlock it. This points to an electrical issue. The window works just fine so hopefully just a bad relay.

I guess I'll take a hack at trying to replace the relay. If I screw something up the worst case is I have to buy a new module anyhow! I'll let you know how it goes.