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.

You May Also Like

How To Answer Customer Ride Control Questions

Presenting your customer with inspection results and benefits of replacement will help sell the job.

Your typical customer is not like you; their point of view is completely different. You must understand what they know and what they value when it comes to their transportation. The old proverb “walk a mile in their shoes” applies to advising customers about shocks and struts.

Selling ride control is difficult. If you just sell them shocks and struts, you are asking the customer to exchange money for a parts and service. Advising and educating a customer about the condition of their car or truck is easy. Presenting your customer with inspection results and benefits of replacement will sell the job without even asking for the sale. 

Broken Springs

What is the cause for the failure? Why does it occur with specific vehicles? The answers might surprise you.

ADAS Module Programming

Reflashing and reprogramming is a necessary service for repairing vehicles.

Tuning Adjustable Shocks and Struts

Let’s take a closer look at adjustable shocks and struts, what they do, and how one should go about adjusting them.

Ball Joint Inspection

It’s important to remember not to miss a worn joint. If a ball joint fails, the driver loses control of the vehicle.

Other Posts

Ride Height Sensors

If one of these sensors is replaced, it must be calibrated after it is installed.

GM Rattle or Creak Noise From Front Suspension

The noise may be originating from the front lower control arm front bushing. Here’s how to correct it.

Mercedes Airmatic Suspensions

Diagnostic tips to aid your repair efforts.

ADAS Sensor Corrections

When performing a calibration, you are adjusting the connection between the sensor, vehicle and surroundings.