Abs Light

March 1, 2008

The abs light and brake light come on about 75% of the

time on my '01 Tahoe. The code is CO265 (EBCM relay circuit).

Any ideas?

Edited March 4, 2008 by 383

66vetteman · July 10, 2010

I had the problem (C0265) on my 2001 Silverado 1500 LT for over a year. Read the post on Module Masters (Thanks Jarrod!!) and removed the unit per MM's instructions, about 15 min, did not undo any brake lines. Sent it in and got it back exactly 1 week from their receiving it which included 4th July holiday. Re-installed and the lights are off for the second straight day. So far, so good. Cost was $16 shipping USPS, insured for $500, with delivery confirmation from Texas. $130 for repairs + $17 FedEx 2 day return shipping. Compare this with dealer cost, not in the same hemisphere. This forum rocks!!

Nick

Shredchief501 · August 22, 2010

Been having the same problem on my 2000 Sierra. Have already done the removal of the EBCM ground will take a look on the front bumper. Having read this forum before, I invested in an inexpensive ABS code reader. They are readily available on Ebay, and work with an OBD II connection. I paid about 80 bucks for mine, in checking on Ebay it looks like there is an Actron ACT-CP9449 for 135 bucks. Unfortunately from my experience they only read ABS codes, I also bought a cheap OBD II scanner on Ebay as well. Both work great and have updatable firmware via internet and have the ability to erase codes and reset lights.

http://actron.com/index.php

snichols001 · February 25, 2011

Hi Matt,

When you replaced the pump unit, did you have to do somethig special to bleed it?

I've seen other posts stating that a tech2 scanner is needed to bleed the unit.

In my case, one of the pump motor leads corroded right off of the motor.

To avoid having to bleed the unit, I just replaced the motor.

Everything works, I am more curious than anything.

Thanks in advance

Steve

If fixing the ground does not help, check the wires that go from the controller box to the ABS pump motor. These are located on top of the motor, so are kid of hard to get at.
Twice I've replaced the entire ABS controller/pump unit (the thing in the frame rail under the driver seat area with the brake lines going in and out). Both times, the two heavy gauge wires (red and black) the power the motor had corroded and broken off where they enter the motor body.

Usually that will give an "Open Motor Circuit" error code, but if the wires are still connected, but severely corroded, you might get others.

Matt

Debo511 · February 25, 2011

When checking G100 Make sure it is mounted to the frame. This ground ( battery to frame ) is often mislocated to the core support if any body work has been done. G110 and several others run through G100.

leesfeed · May 11, 2011

2002 Yukon XL with 154,000. While driving, the ABS light and the !BRAKE! lights came on. Shut the vehicle down and when started back up the lights were extinguished. The brakes are about 50% wear and are working good. I read this thread and found 4 grounds to clean. The one for the battery is located right above the tow hook behind the bumper screwed into the frame. It has two grounds on it. They were pretty dirty. The second one is located on the frame rail forward of the EBCU and has one ground wire. It was not that dirty. The third one is located aft of the EBCU and has one ground wire. It was pretty dirty also. The forth one is located just below and aft of the gas fill line close to the rear bumper. It has two ground wires on it. One goes from the body and I don't know where the other one goes but it looks like its tied into the EBCU wire cluster. This one was VERY dirty and had about 1/8 inch of grime and grease packed around and behind it. It is also the easiest to get to. I might be imagining things but it seems to me that the volt meter is reading about 15 when it usually is on 14 to 14 1/2 after cleaning the battery ground wire. I recently changed the altenator in it also (2 weeks ago). Hopefully this will fix the problem. I will post again either when the lights come back on or in about 2 weeks if they don't come back on again. I love this website and it has helped me diagnose knock sensor problems and now this problem. Be safe!

leesfeed · July 4, 2011

Went to Midas brake shop and paid them 52 bones to diagnose the brake code. EBCM Relay was the code. I removed the EBCM Module from the frame rail, packaged it up and sent it to Moscow, Id. to Module Masters. They charged me 130.00 for the rebuild and 5 bucks for 4 stainless screws to replace the factory ones. The dealership wanted over 600 bones for the module. For a little over 250 with shipping and all I did the repair myself and it has been 4 weeks and all is well. Took 7 days total for the repair. While the module was removed I wrapped the wires and the box where the brake lines go into in a zip lock bag and zip tied it up and drove the vehicle normally. Took 5 minutes to reinstall the module. I am very pleased with Module Masters and with this site. Thank You everyone!!!

z28s10 · August 22, 2011

ok i need some help i have been looking over the forums for a while, my 2000 sierra 103k miles, the abs and the brake light come on at times, and the security and battery, change oil flashes in the information center, at times the volt gauge and fuel hands stop working and the tow/haul won’t work. does anyone have any idea what this could be? I was told that it could be a bad ground, then read it could be the body control module. I am at a loss PLEASE HELP!

scirocco · October 9, 2011

Hey Guys, great topic thanks!

I hope it's OK to post in here instead of starting a new thread...

I have a '95 S-10 (4.3TBI, Ext-cab, 2wd, AWAL brakes) that has an ABS light on... I've looked around at code reader tools and for jumper-and-count-flashes instructions, but it seems that this year (95) is just the cusp of everything ODB-II, and it's not clear exactly how to read the codes on this truck.

I was hoping a GM tech could point me in the right direction? I'm very much looking to handle this myself....

When the truck is started, the ABS light is off. It comes on and stays on at the first press of the brakes. I just got finished replacing a section of the 1/4" line to the rear (rusty) and successfully bled the brakes and have a very normal-feeling pedal. The rears lock up easily with the ABS out of service.

thanks!

BTW: i massively appreciated the design of the AWAL system when i removed te 1/4" rear line from the ABS pump block.... the fact that it is level with the master cylinder, and therefore neither the MC or the pump block get air in them when the system is opened is AWESOME. Gravity bleed after replacing the line was a snap.

Limodriver · March 5, 2012

My 2001 GMC Yukon has had this annoying problem for 3 years. The ABS and brake light would come on for no apparent reason. Restart the truck and they would be off and stay off. This would happen very infrequently, actually a year passed between the first and second occurence.

It then became more frequent until finally this month the lights stayed on. No scan code.

Found this forum and checked the ground wires on the frame underneath the driver's door. Looked nasty. Cleaned up the connectors and the frame location.

Problem solved!

Thanks to all

SuperDel756 · August 16, 2012

Greetings! I drive a 2011 GMC Sierra 1500 with just over 90K miles and have the ABS and Brake warning lights come on and off regularly. Do the issues discussed on this thread (shorts, corroded wires, etc) effect your brake performance or does it just cause the warning lights to come on? My brakes are noticeably "weaker" in addition to the warning lights since the issue started. I had a mechanic buddy check the brake lines, fluid and pads and they were all fine. Thanks!

Edited August 16, 2012 by SuperDel756

jhm · August 16, 2012

Greetings! I drive a 2011 GMC Sierra 1500 with just over 90K miles and have the ABS and Brake warning lights come on and off regularly. Do the issues discussed on this thread (shorts, corroded wires, etc) effect your brake performance or does it just cause the warning lights to come on? My brakes are noticeably "weaker" in addition to the warning lights since the issue started. I had a mechanic buddy check the brake lines, fluid and pads and they were all fine. Thanks!

I can only speak for myself, but when the ABS and BRAKE lights come on randomly, the only effect is the ABS does not work.

gmtech4 · August 16, 2012

Greetings! I drive a 2011 GMC Sierra 1500 with just over 90K miles and have the ABS and Brake warning lights come on and off regularly. Do the issues discussed on this thread (shorts, corroded wires, etc) effect your brake performance or does it just cause the warning lights to come on? My brakes are noticeably "weaker" in addition to the warning lights since the issue started. I had a mechanic buddy check the brake lines, fluid and pads and they were all fine. Thanks!

I can only speak for myself, but when the ABS and BRAKE lights come on randomly, the only effect is the ABS does not work.

correct ,base brakes still work,you need to get the code(s) diagnosed ,no throwing parts at anything ,,,,,take it to your tech ,,

good luck

U.S.A.#1 · August 22, 2012

PEOPLE! Do NOT send your EBCM module in to be 'rebuilt' for $150! This is a HUSTLE! Its cost $0 to fix this problem!

WATCH HERE!

hexumaz · August 25, 2012

I just did the repair as shown in that youtube vid this afternoon. Had a little difficulty with one of the torx bolts and ended up having to dremel it off. Other than having to buy a soldering iron and a tiny torx driver, it was a free fix. So far no lights after the first drive to work!

U.S.A.#1 · August 25, 2012

I just did the repair as shown in that youtube vid this afternoon. Had a little difficulty with one of the torx bolts and ended up having to dremel it off. Other than having to buy a soldering iron and a tiny torx driver, it was a free fix. So far no lights after the first drive to work!

GLAD IT WORKED! I just saved you $150-$200!!! Theres no need to mail it in to be 'rebuilt' as you found out!

Glad it worked!

Take your TIME loosening the torx bolts - they are NOT on tight, its just the heads might strip on you... you can put in stainless replacement bolts if you wish when you're done..

glad my vid helped you solve your problem

--USA#1

PS - here is the video again:

Edited August 25, 2012 by U.S.A.#1