CHECK TRAILER WIRING and TRAILER NOT CONNECTED: Notes

These messages will be displayed if:

• The ITBC system first determines connection to a trailer with electric brakes, and then if the trailer harness becomes disconnected from the vehicle. If a trailer connection is made initially and the vehicle or trailer wiring connections is not correct the TRAILER NOT CONNECTED message will display during key up as if there is no trailer connected. If the TBCM trailer connection is recognized initially and the disconnect occurs while the vehicle is stationary, this message will automatically turn off in about thirty seconds. This message will also turn off if the driver acknowledges this message off or if the trailer harness is re-connected. If the disconnect occurs while the vehicle is moving, the CHECK TRAILER WIRING message will continue until the ignition is turned off. This message will also turn off if the driver acknowledges this message off or if the trailer harness is re-connected or repairs completed.
• There is an electrical fault in the wiring to the electric trailer brakes. The CHECK TRAILER WIRING message will continue as long as there is an electrical fault in the trailer wiring. This message will also turn off if the driver acknowledges this message off. To determine if the electrical fault is on the vehicle side or trailer side of the trailer wiring harness connection, do the following:

1. Disconnect the trailer wiring harness from the vehicle.
2. Turn the ignition OFF.
3. Wait ten seconds, then turn the ignition back to RUN.
4. If the CHECK TRAILER WIRING message re-appears, the electrical fault is on the vehicle side. If the CHECK TRAILER WIRING message only re-appears when you connect the trailer wiring harness to the vehicle, the electrical fault is on the trailer side. Refer to Symptoms - Trailer Brake Controls