04 silvarado is throwing a U1041 code.....

[69SS]

U1041 - Loss of EBCM Communication. What the heck is this? (ebcm)

[Russ Chastain]

Body Control Module? I have heard of that here, but no idea what it actually does.

[p.hinds]

Document ID# 1734167
2004 Chevrolet Chevy C Silverado - 2WD


--------------------------------------------------------------------------------


Subject: ABS Light On, DTCs C0265, C0201, U1041 Set and/or Loss of Communication with Brake Module (Reground EBCM Ground) #04-05-25-002C - (11/23/2005)



Models: 2004-2005 Buick Rainier

2002-2006 Cadillac Escalade, Escalade EXT

2003-2006 Cadillac Escalade ESV

1999-2006 Chevrolet Silverado

2000-2006 Chevrolet Suburban, Tahoe

2002-2006 Chevrolet Avalanche

2002-2005 Chevrolet TrailBlazer, TrailBlazer EXT

2003-2005 Chevolet SSR

1999-2006 GMC Sierra

2000-2006 GMC Yukon, Yukon Denali, Yukon XL

2002-2005 GMC Envoy, Envoy XL

2002-2006 GMC Sierra Denali

2004-2005 GMC Envoy XUV

2002-2004 Oldsmobile Bravada




--------------------------------------------------------------------------------

This bulletin is being revised to provide further diagnostic information and add 2006 model year full-size vehicles. Please discard Corporate Bulletin Number 04-05-25-002B (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




GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION


© Copyright General Motors Corporation. All Rights Reserved.


--------------------------------------------------------------------------------
Document ID# 1734167
2004 Chevrolet Chevy C Silverado - 2WD

[69SS]

Thank you for your help.

[Russ Chastain]

p.hinds is a wonderful person.

- Russ

[HI85WH1]

Gonna go check mine tomorrow...

[diehrd]

p.hinds rules....

[HI85WH1]

Ground is not the cause of my problems... gonna pull the ABS module and send it to modulemasters.com