ABS light on

Good morning,
There are fault codes in the ABS system with the light. These codes will give us a direction to go for a diagnostic.

https://www.2carpros.com/articles/brake-system-warning-light-on

You can have the codes read for free at a parts store. Once you know the codes let me know so we can narrow the area of failure.

Roy

Got it. Looks like the ABS module is the failure

Roy

141,265
Bulletin

Bulletin No: 04-05-25-002

Date: March 10, 2004

TECHNICAL

Subject:
ABS Light On, DTCs C0265, C0201, U1041 Set and/or Loss of Communication with Brake Module (Reground G110 ABS Ground)

Models:
2004 Buick Rainier
2002-2004 Cadillac Escalade, Escalade EXT
2003-2004 Cadillac Escalade ESV
1999-2004 Chevrolet Silverado
2000-2004 Chevrolet Suburban, Tahoe
2002-2004 Chevrolet Avalanche, TrailBlazer, TrailBlazer EXT
2003-2004 Chevrolet SSR
1999-2004 GMC Sierra
2000-2004 GMC Yukon, Yukon Denali, Yukon XL
2002-2004 GMC Envoy, Envoy XL, Sierra Denali
2004 GMC Envoy XUV
2002-2004 Oldsmobile Bravada

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 G110 ABS ground is causing unnecessary replacements of brake modules.

Correction

DO NOT REPLACE THE BRAKE MODULE.

Perform the following steps to improve the connection of the G110 ground:

1. Remove the G110 ground. The G110 ground is located on the frame beneath the driver's side door. If multiple grounds are found in this location, the G110 ground can be identified as the heavy (12-gauge) wire.

2. Clean the area, front and back, using a Whiz Wheel(R).

3. Install the bolt, ground and a star washer to the frame.

4. Install a star washer and nut to the backside of the frame.

Tighten

Tighten the nut to 9 N.M (79 lb in).

5. Cover the front and backside of the repair area using Rubberized Undercoating.

Other codes

Circuit Description

The ABS relay supplies battery voltage to six valve solenoids. The EBCM microprocessor applies the grounds needed to activate each solenoid. The low side of each solenoid coil has a feedback circuit to the EBCM microprocessor. When a solenoid is commanded OFF, the feedback voltage is high. When a solenoid is commanded ON, the feedback voltage is low.

Conditions for Running the DTC

-The ignition is ON.
-The vehicle speed is greater than 6 km/h (4 mph).

Conditions for Setting the DTC

The EBCM detects an internal malfunction.

Action Taken When the DTC Sets

C0246, C0251, C0252, C0253 and C0254

If equipped, the following actions occur:
-The EBCM disables the DRP/ABS.
-The ABS indicator turns ON.
-The red brake warning indicator turns ON.

C0247 and C0248

If equipped, the following actions occur:
-The EBCM disables the ABS.
-The ABS indicator turns ON.

Conditions for Clearing the DTC

The Conditions for Setting the DTC are no longer present and you use the scan tool Clear DTC's function.

Diagnostic Aids

An intermittent open/shorted solenoid DTC can be set by several different internal EBCM problems. Replace the EBCM if an open/shorted solenoid DTC continues to set intermittently.