GM Tech Tip: Trailer Wiring Damages Body Control Module

GM Tech Tip: Trailer Wiring Damages Body Control Module

GM cautions not to splice in trailer light wiring into the factory wiring harness when preparing for trailer towing on Acadias, Enclaves, Outlooks and Traverses. On these vehicles, the circuits for stop lamps/turn signals, tail lights and the lighting grounds are controlled through the Body Control Module (BCM).

trailer-wiring-bcm-featured

Models: 2008-’11 Buick Enclave, 2009-’11 Chevrolet Traverse, 2007-’11 GMC Acadia, 2007-’11 Saturn Outlook

Condition: Installing trailer wiring on a vehicle not equipped with a towing package.

Repair Procedure: GM cautions not to splice in trailer light wiring into the factory wiring harness when preparing for trailer towing on Acadias, Enclaves, Outlooks and Traverses. On these vehicles, the circuits for stop lamps/turn signals, tail lights and the lighting grounds are controlled through the Body Control Module (BCM).

Model year 2007-’11 vehicles not equipped with a towing package must be modified by installing a new Underhood Bussed Electrical Center (UBEC) cataloged for vehicles with a towing package. Check with a GM dealer for the appropriate part number. Order the UBEC for the vehicle with the same options as equipped plus trailer towing package option V92.

Model year 2007 vehicles must also modify the backup light circuit after installation of the new UBEC. Start by disconnecting Connector X7 from the BCM. Remove the terminal for Pin 3 from the connector: the wire color is dark blue. Reconnect the Connector X7 to the BCM. Cut the terminal off of the dark blue wire and strip the end. Splice this wire into the light green wire, pin 2, of the 24-pin Connector X6 on the BCM.

Courtesy of ALLDATA.

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