Answer

DTC C0201

Circuit Description

The system relay, located within the electronic brake control module (EBCM), supplies battery voltage to all of the valve solenoids and to the ABS pump motor. When the relay contacts close, the EBCM monitors the voltage supplied to the valve solenoids and compares this voltage to monitored ignition voltage.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0201 Antilock Brake System (ABS) Enable Relay Contact Circuit

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The EBCM detects that the voltage supplied to the valve solenoids is less than 80 percent of monitored ignition voltage for 50 milliseconds.

Action Taken When the DTC Sets

•	The EBCM disables the ABS/DRP.

•	The ABS indicator turns ON.

•	The brake warning indicator turns ON.

 

 

 

Here is a bulletin that may help you repair the fault.

 

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

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Subject:

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

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:

1. 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.
2. Clean the area, front and back, using a Whiz Wheel®.
3. 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.

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

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

5. 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