Subject: | "Check Trailer Wiring" Message Displayed On DIC |
Models: | 2007 Chevrolet Silverado |
2007 GMC Sierra |
With RPO JL1 |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Some customers may experience an intermittent "Check Trailer Wiring" message in vehicles equipped with ITBC (Integrated Trailer Brake Controller) RPO JL1 and no DTC's stored. This message may be displayed each time the trailer's running lamps, turn signal lamps or brake lamps are turned on, especially if the trailer is equipped with a large number of lamps.
This condition is caused by insufficient grounding between the trailer and vehicle.
To correct this condition, perform the following procedure:
Inspect and clean the ground wire (normally white wire) connection on the trailer side of the 7-pin connector.
• | Make sure that the wires inside the trailer side connector are clean and securely fastened. |
• | If an electrical junction box exists on the trailer, make sure the wires inside the junction box are clean and securely fastened. |
Once this procedure is complete, check to see if the condition has been corrected, if not contain below.
• | Pre-drill trailer chassis location with a 3/16" hole. |
• | Make sure the trailer chassis location is clean of paint or coating material prior to installation. |
• | Galvanic corrosion between dissimilar trailer and screw metals may require that this ground location be periodically cleaned. |
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.