Brakes - ABS Telltale Lamp ON/DTC C0550 Stored
File In Section: 05 - BrakesBulletin No.: 03-05-25-003
Date: April, 2003
TECHNICAL
Subject:
ABS Telltale Illuminated, DTC C0550 Stored in History (Reprogram Electronic Brake Control Module (EBCM))
Models:
2003 Chevrolet Express
2003 Chevrolet Silverado with GVW Rating over 8600 lbs
2003 GMC Savana
2003 GMC Sierra with GVW Rating over 8600 lbs
Condition
Some customers may comment on a permanent illuminated ABS telltale lamp. When checking for DTCs with the diagnostic scan tool, you may encounter DTC C0550 stored in history.
Cause
The HVAC blower motor, when the vehicle is keyed off, may generate sufficient electrical power during it's coast down period to cause a false C0550 code to set in the ABS module. The generated power created by the blower motor is of a "dirty" erratic nature, which cannot be correctly interpreted by the ABS module.
Correction
Reprogram the EBCM with the new service calibration, which was available from Techline starting April 14, 2003 on the T152000 version 4.0 or later. This calibration is an electronic calibration and is not available from GMSPO. DO NOT REPLACE the EBCM for this condition unless normal diagnosis identifies the module as the cause.
Warranty Information
For vehicles repaired under warranty, use the table.
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