Silverado Classic 1500 4WD V8-4.8L (2007)
Trailer Brake Control Module: Customer Interest
Electrical - 'No Trailer Connected' Message On DIC
TECHNICAL
Bulletin No.: 09-05-22-004
Date: November 05, 2009
Subject: No "Trailer Connected" Message on Driver Information Center (DIC) at Startup When Trailer is Connected (Reprogram ITBCM)
Models:
2007-2008 Chevrolet Silverado
2007-2008 GMC Sierra
Equipped with Integrated Trailer Brake (RPO JL1)
Condition
Some customers may comment that when they connect their trailer, with the engine off, and after they start the engine, the Trailer Connected message is
not displayed on the DIC. With the engine running, if the trailer connector is cycled, the vehicle will detect the trailer and display Trailer Connected.
This concern should only affect trailers equipped with trailer brakes on a single axle.
Cause
The trailer brake control system is only compatible with trailers equipped with electric trailer brakes. The system will not work or detect trailers
equipped with any other types of brakes such as surge, air or electric-over-hydraulic trailer brake systems. When a trailer is connected, the Trailer Brake
Control Module (TBCM) performs a test to determine if the trailer is equipped with electric trailer brakes. If the trailer wiring or electric trailer brake
magnets have additional resistance (caused by poor connections, corrosion, improper splices, etc.), the TBCM may not be able to detect the trailer.
Correction
A revised calibration has been developed to address these issues. Reprogram the Integrated Trailer Brake Control Module (ITBCM) with updated
calibration files using the TIS2WEB Service Programming System (SPS) application. Refer to SI and Service Programming System (SPS)
documentation for programming instructions, if required. Refer to Trailer Brake Control Module Programming and Setup in SI.
Warranty Information
For vehicles repaired under warranty, use the table.
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