Abs Light

[383]

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

[383]

Bump.

[bobcat5544]

Document ID# 1988903

2001 Chevrolet Tahoe - 4WD

 

 

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Subject: ABS Light On, DTCs C0265, C0201, U1041 Set and/or Loss of Communication with Brake Module (Reground EBCM Ground) #04-05-25-002D - (06/14/2007)

 

 

 

Models: 2004-2007 Buick Rainier

 

2002-2006 Cadillac Escalade, Escalade EXT

 

2003-2006 Cadillac Escalade ESV

 

1999-2007 Chevrolet Silverado Classic

 

2000-2006 Chevrolet Suburban, Tahoe

 

2002-2006 Chevrolet Avalanche

 

2002-2007 Chevrolet TrailBlazer, TrailBlazer EXT

 

2003-2006 Chevolet SSR

 

1999-2007 GMC Sierra Classic

 

2000-2006 GMC Yukon, Yukon Denali, Yukon XL

 

2002-2007 GMC Envoy, Envoy XL, Sierra Denali Classic

 

2004-2005 GMC Envoy XUV

 

2002-2004 Oldsmobile Bravada

 

 

 

 

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This bulletin is being revised to update model years. Please discard Corporate Bulletin Number 04-05-25-002C (Section 05 -- Brakes).

 

 

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Condition

Some customers may comment that the ABS light is on. Upon further inspection, DTCs C0265 and C0201 may be set in the brake module. It is also possible for DTC U1041 to set in other modules. There may also be a loss of communication with the brake module.

 

Cause

A poor connection at the EBCM ground is causing unnecessary replacements of brake modules.

 

Important: The EBCM Ground is different for each application. Refer to the list below for the proper ground reference:

 

• Midsize Utilities = Ground 304

 

• SSR = Ground 400

 

• Fullsize Trucks and Utilities = Ground 110

 

 

Correction

DO NOT REPLACE THE BRAKE MODULE.

 

Perform the following steps to improve the connection of the EBCM Ground:

 

Remove the EBCM Ground. The EBCM Ground is located on the frame beneath the driver's side door. If multiple grounds are found in this location, the EBCM ground can be identified as the heavy (12-gauge) wire.

Clean the area, front and back, using a Whiz Wheel®.

Install the ground, then the washer and then the bolt to the frame.

Important: It is important to use the bolts, washers and nuts specified in this bulletin. These parts have been identified due to their conductive finish.

 

Install a washer and nut to the back side of the frame.

Tighten

Tighten the nut to 9 N·m (79 lb in).

 

Cover the front and back side of the repair area using Rubberized Undercoating.

An additional check can be made to ensure a good connection for the Battery Cable to Frame ground. It is possible for this ground to cause similar symptoms with the ABS as described above.

 

Parts Information

FULL-SIZE TRUCKS, SUVs AND H2

 

Part Number

Description

 

11588564

Bolt

 

15650962

Washer

 

15672934

Nut

 

12378398

 

(in Canada, 10952414)

Rubberized Undercoating -- Paintable

 

MIDSIZE SUVs

 

Part Number

Description

 

11517555

Bolt

 

15650961

Washer

 

11503749

Nut

 

12378398

 

(in Canada, 10952414)

Rubberized Undercoating -- Paintable

 

 

Warranty Information

For vehicles repaired under warranty, use:

 

Labor Operation

Description

Labor Time

 

N9502

Ground Repair - EBCM Ground

0.2 hr

[383]

Thanks for the help Matt. I cleaned the ground where

it is fastened to the frame and it didn't fix the problem.

Is it nessesary to replace the bolt, washer, and nut

instead of just cleaning them? I didn't think of checking

the battery to frame connection, I'll do that tomorrow.

[billa32778]

I have a 2000 GMC Sierra 1500 with the same problem. I've cleaned and reinstalled the three grounds I could find along the frame with no luck.

 

My son printed a picture of gound 110, which according to his source is located on the front shock mount... no such ground exists on any GM product I've looked at.

 

I've had a Snap-On scanner give me codes CO265, CO245, CO241. CO251, CO246 and CO242. All of them seem to be connected with the ECBM. The only codes with any suggestions to them want you to check the 10 pin and 2 pin connectors, which I'm assuming the 2 pin connector is the one located on top of the shock mount and connects the wiring harnes to the lead that goes to the sensor in the front wheel hub.

 

My Brother-in-law says he's seen this kind of problem and it usually is a bad wire connection in the front bearing hub (he said you wouldn't believe how small a wire they use for this connection) and replacing the front hub/bearing solves it. He also mentioned that an ABS brake scanner will pinpoint which side is causing the problem... is an ABS Scanner going to give me a better reading on the system?

 

Anybody have any other input... I'll be cleaning the 2 pin connectors today and will let you know what happens.

[TBLAZER]

I have a 2000 GMC Sierra 1500 with the same problem. I've cleaned and reinstalled the three grounds I could find along the frame with no luck.

 

My son printed a picture of gound 110, which according to his source is located on the front shock mount... no such ground exists on any GM product I've looked at.

 

I've had a Snap-On scanner give me codes CO265, CO245, CO241. CO251, CO246 and CO242. All of them seem to be connected with the ECBM. The only codes with any suggestions to them want you to check the 10 pin and 2 pin connectors, which I'm assuming the 2 pin connector is the one located on top of the shock mount and connects the wiring harnes to the lead that goes to the sensor in the front wheel hub.

 

My Brother-in-law says he's seen this kind of problem and it usually is a bad wire connection in the front bearing hub (he said you wouldn't believe how small a wire they use for this connection) and replacing the front hub/bearing solves it. He also mentioned that an ABS brake scanner will pinpoint which side is causing the problem... is an ABS Scanner going to give me a better reading on the system?

 

Anybody have any other input... I'll be cleaning the 2 pin connectors today and will let you know what happens.

Check the ground connection at the front left side of the frame,behind the bumper area,this is the battery to frame ground.

[billa32778]

Check the ground connection at the front left side of the frame,behind the bumper area,this is the battery to frame ground.

 

 

That's one of the three grounds that I took apart, cleaned up with a drumel wheel and reattached. The second one was on the front driver side cab mount (just in front of the EBCM) and the third one is in the back just behind the gas filler door.

[doropallo]

Check the ground connection at the front left side of the frame,behind the bumper area,this is the battery to frame ground.

 

I cleaned all 3, one at a time, and the culprit seems to have been the one behind the bumper on the driver's side. The lights have been off all day, hope it did the trick. Figured it was the ground when I had to give a guy at work a jump start and couldn't draw enough power through the frame, had to use the negative on the battery. And then the light went out too. This board rocks.

[doropallo]

The ABS/Brake light came on again today, oh well, don't have time to look into anything else now. It does get frustrating, turn off the truck and try to get someone with a brake code reader and then turn the truck on and the lights aren't lit. They think I am nuts.

[mooreapi]

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

[Califxr]

Hi all!!! Well its my turn. A week ago my 01 2500HD rolled over 75 thousand miles and I put a for sale sign on it, and now the abs and brakelight has come on 3 times since. Its like it was programed to fail. I turn the motor off and back on and it goes away for a day or 2. Have any of you really had success repairing the grounds? I hope so, I'll try this weekend. Unfortunatlly its intermitten so it will take awhile before I know its fixed. Any other suggestions?

Gene

[jbordi]

Kesley Hayes Modules need to be rebuilt. I did try the ground with mine before sending off to have it rebuilt. See absfixer.com and modulemaster.com. The rebuilt ones are ten times better than the factory ones. Good luck.

[Draenor]

Kesley Hayes Modules need to be rebuilt. I did try the ground with mine before sending off to have it rebuilt. See absfixer.com and modulemaster.com. The rebuilt ones are ten times better than the factory ones. Good luck.

[jbordi]

You need

[c4racer]

Check the ground connection at the front left side of the frame,behind the bumper area,this is the battery to frame ground.

 

I cleaned all 3, one at a time, and the culprit seems to have been the one behind the bumper on the driver's side. The lights have been off all day, hope it did the trick. Figured it was the ground when I had to give a guy at work a jump start and couldn't draw enough power through the frame, had to use the negative on the battery. And then the light went out too. This board rocks.

 

 

indeed - quite frustrating. I thought I had it licked. First I replaced the right side hub. No change - lights came right back on. Next I replaced the left side hub and the light stayed off. Or so I thought. On a longer drive it eventually came on again.

 

So I cleaned the body computer ground under the drivers door. Again - I thought that fixed it because I did two drives without any lights. Then this AM on the 4th drive it came on again. Damn. Of course - I have the burb for sale now, and I thought I had this fixed... Damn. What a PITA.

 

So I guess next is the ground behind the front bumper? Where is that exactly? I had trouble finding it. I have a 2500 series 2001 Suburban.

[bill190]

Have you read the codes from the ABS to find the specific problem?