I haven't posted here in a long time, but I just had a problem with my 2003 C5. I was crossing a set of RR tracks, when the brakes locked up and the ABS and TC lights came on in the dash. I can't leave it sit on the tracks, so I just gassed it up and got it off the tracks to the side of the road. I shut the car off and sat there a minute, then decided to start it again. Brakes had unlocked, so I drove it home with the lights on in the dash. Well, I know what the problem is-- the EBCM. This is the 2nd time this happened. I had the EBCM repaired the first time. What is funny is that the first time I had no brake lockup, just lights in the dash. The second time the brakes locked up tight. When I got home I pulled the codes: C1248H, C1255H, C1271H C. I then tried to reset all the codes to see what came up currently. All codes cleared except C1271H C. That one would not clear, but no more codes were set. The C1248 and C1271 codes are not listed in the code list found on this forum. So now not sure what the problem is.
The brake lockup has me wondering of there is another problem besides the EBCM. As this EBCM has been opened up once already, I would just as soon buy a new EBCM if that is the problem. I just don't want a new one to blow up also due to a different problem. The EBCM in my car is the 10331729 PB model. It appears there is another model number used on these cars, 10343433. Are these interchangeable? My gut says "NO".
Thanks for any help?

 

My code information says DTC C1261-C1274 refer to EBCM Internal Solenoid Circuit. Hope this helps.

Ron

 

Here is the specific description for your C1271 error that won't clear;

C1271 LF TCS Master Cylinder Isolation Valve Malfunction

Here is the description for C1248;

C1248 DRP Disabled

Both of these errors are for the EBCM module.

Gary

 

Thanks guys. So it appears that replacing the EBCM should fix the problem.
So what about the interchangeability between the 2 model numbers?