Customer Concern: All the brake lights on the truck work properly but the trailer brake lights don't work. The trailer parking lights and turn signals all are working. There are no codes in the Totally Integrated Power Module (TIPM).
Tests: 1. Check brake switch operation in the Totally Integrated Power Module (TIPM).
2. If the brake switch input doesn't change from yes to no or applied to not applied check power feed at the TIPM C6 connector pin #7 the White/Tan wire - should have power when the brakes are applied.
Potential Causes: Totally Integrated Power Module (TIPM)
Totally Integrated Power Module (TIPM) Wiring
Confirmed Fix: Repaired Totally Integrated Power Module (TIPM) Connector: Repaired TIPM C6 connector pin 7 for a bad connection causing the TIPM to not see brake switch input.
Tech Tips: The brake input to the TIPM is hard wired from the brake switch. The wiring diagram forgets to put the switch in there but shows a splice # with no input. It appears to be a high side driver at the TIPM for brake switch output but its being fed so the TIPM knows the brakes are applied. Then the TIPM puts out voltage to the trailer wiring for the brakes.