Biotex

Bill,
I was typing in those codes as you replied. See my edited list above please.

So is it looking like the BCM is bad?

Biotex

Bad BCM?

Biotex

I don't have any reason why I was asking if the Body Control Module was bad. I'm about ready to start swapping parts since I don't know what else to do at this point.
I just read that the BCM needs to be programmed in with a Tech II programmer, so that would be a 300 mile journey for me. The EBCM would be something I can do.

Biotex

Looks like I'm going to send the EBCM into have it looked at and repaired if possible. The TCS -NO COMM probably means it is shot. Hope not. I would like this car code free.

Bill Curlee

To make the EBTCM work, Have communications, you have to have POWER, GROUND, a operational microprocessor and signal out.

You better be probing the main connector to make sure that you have power and ground.

The ABS Fixers CAN NOT FIX a NO COMMS issue. Don't waste you time and money sending it out. If the microprocessor isn't working, its DONE.

Nine times out of ten, its a power ground issue.

I will attach you power ground schematic after dinner.

Bill

Bill Curlee

Bill Curlee

Make SURE that you have battery power on fuse #5

Biotex

Bill,
Thank you for taking the time to help me go one step further to get this resolved. I will check grounds and power at the connector as you suggested.
I would like to hear your input on this companies claim:
http://www.ebay.com/itm/291147215942?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
I talked with one of their techs, and he told me that they have found a way to repair the NO COMM faults. He said that unlike the other repair facilities, they will completely rebuild the unit with a 24 hr turnaround. It is a lot cheaper also, and carries the lifetime warranty.

Worth a shot IMO. For $50 I'll try it and report back.
They do have a stand alone website, but they charge $66 IIRC going through that way. I'll do the auction site deal.

The way I see it, there is no way a tech can completely repair or replace all the components inside for that kind of money. My guess is they are swapping the guts with ready to go units. Probably overseas components, but with a lifetime warranty, I don't care.

tytek

Any updates after sending the EBCM out? Have you had any luck getting rid of these codes? I have the same issue right now, and have intermittent three codes: PCM P1571, TCS C1277, SDM U1040...

They do come on randomly, and once cleared reappear again. Doesn't matter if the car is moving or stopped and idling.

Haven't checked the grounds yet, but was curious to see where your troubleshooting has taken you so far. I do have a spare EBCM sitting here, so may swap it in to see.

My problem is that this is my dedicated track car, and I have a weekend event that I was going to take it to later today. May have to take my 'street' Vette instead...

Bill Curlee

DTC C1277 LF Solenoid Circuit Shorted to Voltage

Biotex

I have not taken the EBCM out for repair yet. I just installed a new two post lift in my shop so I can work on the C5 easier. It is now up and running, and I just the other day lifted the car for the first time. I'm a little nervous working under a lifted car, but I do feel it is safer than on jack stands.
I hope to pull the EBCM later today or tomorrow, and send it in to the company I referenced above. I will report back.

tytek

Here is an update to MY problem and its solution that may be beneficial to others.

I had four codes present: p1277, p1689, 1040, and 1571 and occasional TCS No Comm. They were random in nature and would appear at different times.

By doing Bill's checks suggested above with a multimeter, I realized that ABS fuse #5 in the engine compartment fuse panel was only sometimes reading voltage. But the fuse looked fine and was not burned out. I replaced with a new 10A one and the problems went away. To make sure that it was the cause, I turned ignition ON with the new fuse removed. Same TCS no comm ABS light came on.

Hope that it will solve my issues, but I guess time will tell. Have an autox event this coming Sunday. Ultimate litmus test!

Biotex

Update:
I pulled the EBCM and shipped it to a company in Mesa Arizona for repair. Should have it back in a couple of days since they boast a 24 hour turnaround. Best part of it is that I found the missing screw that I dropped the last time I pulled the module. Now I have six screws again.
Will update how this turns out. They advertise a lifetime warranty.

Smoken1

I used the same company for my c1242 code
Fixed the first time and no problems since then

Biotex

Installed the repaired EBCM today. Before I hooked up the electrical, I reset all codes on the DIC. Turned the key to the on position, and I noticed a check engine soon message. Started the car, pressed the reset, and went for a drive.
I did not get any messages during the drive. Before, I would get the active handling message, and the ABS message. Now I just get the two lights on the dash.
Pulled codes as follows:
10 PCM P1571 H C
28 TCS NO COMM
40 BCM B0502 H C
---------B0507 H C
---------B2482 H C
58 SDM U1040 H C

Suggestions?

tytek

Check for 12VDC on all the fuses in both panels. My fuse 53 IIRC was fine after visual inspection, but voltage on it was intermittent. All grounds and connections were fine, clean, and didn't seem to be a problem. I had a few of the same codes...

Bill Curlee

Until you can positively confirm that you have proper power and ground on the EBTCM, there is not much more that we can do. Once you check for power and ground, the next steps are a little more logical to follow.

If I were a betting man,, I would wager that your missing power from or have a poor connection in your IGNITION SWITCH.. At least check to see that you have FULL BATTERY voltage on the fuses that are powered by the Ignition ON buss.

BC

Biotex

You talking about removing the large connector at the EBCM and testing for voltage at A,E, &D and Gnd at B on the connector side correct? Is it better to leave it connected and back probe it?
A = battery +
B = Ground
E = battery +
D = battery +

I have already verified voltage at the fuses, but can't hurt to do it again.

Smoken1

BC had me do the switch repair also to eliminate that as a possibility. Follow his post on the repair.

94redrag

I'm having the exact same issue. I get the following codes and only these codes;


PCM P1571 ASR Desired Torque
28 TCS No Comm.
58 SDM U1040 H C

I've tried all the tests that BC has suggested and everything checks out good.

I'll be following this thread closely.