TOYOTAKARL case: GMC Sierra ABS/Brake light issue

[Its me]

So for the past few years I have been living with the ABS light and Brake light both occasionally coming on while driving my 2000 GMC Sierra. If you turn the truck off, the lights go off and may stay off for days or only hours… So a few years ago I pulled the brake error code C0265 with my MODIS so I knew I was dealing with either a ground issue or an Electronic Brake Control Module (EBCM) that was going bad. The EBCM new is very pricey at around $600-$700 where you look. The good news is that you can get EBCM’s rebuilt for anywhere from $60-$100.

As I have been trying to get the GMC back to tip top shape and I am now living in a State which experiences a lot of snow and ice, I am going to address this now. There is a Technical Service Bulletin (TSB) about this exact issue. I have checked the battery ground cable and found no issues, so this is the repair I hope will take care of the problem. I completed the repair and drove the vehicle for over an hour and a distance of 50 miles, without a light… I still have my fingers crossed.

If I do get this error code again, I will have no choice but to remove the EBCM and get it re-built or replaced. The difficult part is the location of this on the Truck. It is attached to the ABS hydraulic unit on the frame on the drivers side and the top of the EBCM has little access to remove the screws. It is most likely that I will have to remove the whole assembly to gain access to this. The EBCM is held on by 4 torx screws which can strip out easily…. If I remove the hydraulic unit, I will have to completely re-bleed the whole system by using my MODIS because there is a bleed mode procedure that has to be done for this year and model GMC. This is not something I want to do, but will if necessary.

At the end of this post, I have included the actual TSB for this procedure.
This is a very simple procedure, but I post it here in case someone else may be having the same issue.

The first thing I did is call and ordered the parts, the dealership got them for me the next day.
All that is required is:

1. Washer – part number 11609679 – Price $.85
2. Bolt – part number 11588564 – Price $1.98
3. Nut – part number 11609746 – Price $1.50

Note: These nut and the washer numbers I have listed are different from the TSB due to a change in part numbers.

Additionally I needed rubberized paint, but since GM wanted $28 a can, I bought a can of rubberized paint for $4.99 at the local Advance Auto.

First I located the ground. I confirmed this was the ground by disconnecting it and starting the vehicle… Immediately the ABS light came on and stayed on.

Next I removed the bolt and nut.

Old and new… Both old and new nuts and bolts were 13mm….

I then prepped the surface with a wire brush to clean the contact area…

Then I installed the new bolt and nut..

Then I applied the rubberized paint.

Although it is not a master paint job, nobody ever looks down there and it is for practicality 😉

Hopefully this will be the end of the ABS light. If I have to replace the EBCM, I will post the work here.

Cheers!
-Karl!

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

——————————————————————————–

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

——————————————————————————–

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

Topic

[dave]

It would have been cool to get a voltage drop reading over the ground strap/nut just to see if it exceeded the .10 volt ASE standard for ground circuit resistance. Awesome post btw, glad you found a TSB that specifically addressed the problem. It does seem weird to run a ground wire of such a critical component to a place that is exposed on the frame and could be more susceptible to corrosion than if it were hidden in the engine compartment for example.

[Its me]

[quote=”Wrench Turner” post=68692]It would have been cool to get a voltage drop reading over the ground strap/nut just to see if it exceeded the .10 volt ASE standard for ground circuit resistance. Awesome post btw, glad you found a TSB that specifically addressed the problem. It does seem weird to run a ground wire of such a critical component to a place that is exposed on the frame and could be more susceptible to corrosion than if it were hidden in the engine compartment for example.[/quote]

Dang it, you are right… This would have been a perfect opportunity to document a voltage drop test… I am kicking myself now….

Cheers!

Karl

[Author]

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