Bulletin BES 04-22

Subject: Anti Lock Brakes: Poor ground sets false ABS codes

Vehicle Involved: 2004 Rainier 2002-2004 Escalade, Escalade EXT 2003-2004 Cadillac Escalade ESV 1999-2004 Silverado 2000-2004 , Tahoe 2002-2004 , Trailblazer, Trailblazer EXT 2003-2004 Chevrolet SSR 1999-2004 GMC Sierra 2000-2004 GMC Yukon, Yukon Denali, Yukon XL 2002-2004 GMC , Envoy XUV, Envoy XL, Sierra Denali 2002-2004 Bravada

Condition: Poor ground connection at the Electronic Brake Control Module (EBCM) is causing unnecessary replacements of ABS brake control modules.

Repair Procedure: The EBCM ground location is different for each of the above listed applications. The Original Equipment (OE) service manuals reference ground number 304 for midsize utility vehicles. Ground number 400 is for the SSR. Ground number 110 is for full-size trucks and utilities.

The ABS light may be illuminated on some of these vehicles. Diagnostic trouble codes (DTC) CO265, C201 may be set. It is also possible that code DTC U1041 may be set in other modules. Sometimes the diagnostic scan tool may indicate a loss of communication with the brake control module.

Do not replace the brake module.

• Locate and remove the ABS brake controller ground. • Clean the ground strap location. (Most locations are on the frame beneath the driver’s side door). Clean both sides. • Install the bolt, ground strap and star washer to the frame. • Install the star washer and nut to the backside of the frame. • Tighten the nut securely. • Seal the front and backside of the repair with a rubberized undercoating.

NAPA Brake and Chassis ■ 4400 Prime Parkway ■ McHenry, IL 60050 ■ (815) 363-9000