ABS and brake light on - The 1947 - Present Chevrolet & GMC Truck Message Board Network

cstm68 · 10-26-2011, 12:35 AM

iv had my 01 for about 3 years now, its an z71 that i put a 6'' lift and 35'' tires on about a month after i bought it. About 2 monthes ago my brake light and abs light started to come on here and there, the truck has 118000 miles on it. I pluged it into a scan tool to read the codes and its tripping the EBCM code, (electric brake control modual) iv been told that its due to my spedo being off since it had 35'' tires and that if i recalibrate the spedo it will fix this. Has anyone eles had this problem or have any ideas whats goen on? thanx

clinebarger · 10-26-2011, 01:17 PM

Whats the code number?

northerngmc · 10-28-2011, 12:00 PM

I have had 2 issues on my 04 2500HD with the brake/abs light coming on. First time I was able to go under the cab and clean the ground cable to the computer and it was better after that. The gorund cable for the brake computer is located on the bottom of the cab directly below were your left foot sits when driving.

Second time the light came on I tried to clean the ground but this did not help. I did some research and found that if your batteries (2 in a diesel) are getting older and the computer does not see full voltage at start up it will trip a code as well. Truck was 7 years old so I replaced both batteries last spring and all is fine.......

Not sure if either would help your situtation but thought I would pass along my experience with the brake/ABS light system.

cstm68 · 10-28-2011, 03:56 PM

clinebarger, ill run a scan on it again this afternoon and get a code

northerngmc, my bat is only 6 monthes old, ill try cleaning that ground

chvtrkman · 10-30-2011, 04:56 AM

I've got the same problem with our '02 Suburban.I haven't crawled under it to check the ground cable seeing that we got 8" of snow yesterday.Just wondering....Could there be air in the lines? I just had shop change all the steel lines recently.

cstm68 · 10-30-2011, 09:50 PM

i cleaned the ground and the lights still come on, i ran another scan on it and the code is c0265 (EBCM relay circut)

chvtrkman if there was air in the lines the petal would feel soft and you would need to pump the petal when brakeing

clinebarger · 10-30-2011, 10:14 PM

DTC C0265:

1. Verify 12 volts power on the Red wire, and ground on the Black wire, at the two pin connector to the Electronic Brake Control Module (EBCM).

2. Disconnect the plug from the bottom of the EBCM going to the motor. Then power and ground those wires and verify the motor runs and how it sounds.

3. If the motor runs and sounds fine, then the EBCM has to be replaced.

4. If the motor does not run, replace the motor and retest to see if the code returns.

The pump motor relay is built internally of the EBCM and can only be serviced as the whole EBCM. Also note that if the pump motor is bad, it can damage the relay from too much current draw.

10-26-2011, 12:35 AM	#1
cstm68 Registered User Join Date: Jan 2007 Location: shoreline, wa Posts: 1,565	ABS and brake light on iv had my 01 for about 3 years now, its an z71 that i put a 6'' lift and 35'' tires on about a month after i bought it. About 2 monthes ago my brake light and abs light started to come on here and there, the truck has 118000 miles on it. I pluged it into a scan tool to read the codes and its tripping the EBCM code, (electric brake control modual) iv been told that its due to my spedo being off since it had 35'' tires and that if i recalibrate the spedo it will fix this. Has anyone eles had this problem or have any ideas whats goen on? thanx __________________ 68 swb fleet bagged on 20's 327 with 4 speed http://67-72chevytrucks.com/vboard/s...d.php?t=223308 2014 Chevy 2500hd duramax CCLB

10-26-2011, 01:17 PM	#2
clinebarger Senior Member Join Date: May 2009 Location: Fort Worth, TX Posts: 6,370	Re: ABS and brake light on Whats the code number?

10-28-2011, 12:00 PM	#3
northerngmc Registered User Join Date: Jan 2004 Location: Whitehorse YK Canada Posts: 2,651	Re: ABS and brake light on I have had 2 issues on my 04 2500HD with the brake/abs light coming on. First time I was able to go under the cab and clean the ground cable to the computer and it was better after that. The gorund cable for the brake computer is located on the bottom of the cab directly below were your left foot sits when driving. Second time the light came on I tried to clean the ground but this did not help. I did some research and found that if your batteries (2 in a diesel) are getting older and the computer does not see full voltage at start up it will trip a code as well. Truck was 7 years old so I replaced both batteries last spring and all is fine....... Not sure if either would help your situtation but thought I would pass along my experience with the brake/ABS light system. __________________ Blaine 59 GMC 9314 a.k.a. Whoopee 68 C20 50th Anniversary a.k.a. The Rat http://www.flickr.com/photos/northerngmc/ http://www.members.tripod.com/P-wee/index_032.htm 1.61803 is one H of a lot better than 3.14159, no really it is!

10-28-2011, 03:56 PM	#4
cstm68 Registered User Join Date: Jan 2007 Location: shoreline, wa Posts: 1,565	Re: ABS and brake light on clinebarger, ill run a scan on it again this afternoon and get a code northerngmc, my bat is only 6 monthes old, ill try cleaning that ground __________________ 68 swb fleet bagged on 20's 327 with 4 speed http://67-72chevytrucks.com/vboard/s...d.php?t=223308 2014 Chevy 2500hd duramax CCLB

10-30-2011, 04:56 AM	#5
chvtrkman Registered User Join Date: Sep 2007 Location: PA. Posts: 178	Re: ABS and brake light on I've got the same problem with our '02 Suburban.I haven't crawled under it to check the ground cable seeing that we got 8" of snow yesterday.Just wondering....Could there be air in the lines? I just had shop change all the steel lines recently. __________________ _____________________________________________ 69 C-20 292, 4 spd O/D, 4:56 rears. No a/c p/s p/b p/w......restoration project,"Operation:Stovebolt" 78 C-10 305 TH350 new (old) daily driver 02 Suburban Z71 a.k.a. the family truckster 99 Silverado 1500 Z71

10-30-2011, 09:50 PM	#6
cstm68 Registered User Join Date: Jan 2007 Location: shoreline, wa Posts: 1,565	Re: ABS and brake light on i cleaned the ground and the lights still come on, i ran another scan on it and the code is c0265 (EBCM relay circut) chvtrkman if there was air in the lines the petal would feel soft and you would need to pump the petal when brakeing __________________ 68 swb fleet bagged on 20's 327 with 4 speed http://67-72chevytrucks.com/vboard/s...d.php?t=223308 2014 Chevy 2500hd duramax CCLB

10-30-2011, 10:14 PM	#7
clinebarger Senior Member Join Date: May 2009 Location: Fort Worth, TX Posts: 6,370	Re: ABS and brake light on DTC C0265: 1. Verify 12 volts power on the Red wire, and ground on the Black wire, at the two pin connector to the Electronic Brake Control Module (EBCM). 2. Disconnect the plug from the bottom of the EBCM going to the motor. Then power and ground those wires and verify the motor runs and how it sounds. 3. If the motor runs and sounds fine, then the EBCM has to be replaced. 4. If the motor does not run, replace the motor and retest to see if the code returns. The pump motor relay is built internally of the EBCM and can only be serviced as the whole EBCM. Also note that if the pump motor is bad, it can damage the relay from too much current draw.



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