Brake Signal Circuit: Notes

Fig 1: Brake Signal Circuit Diagram

Courtesy of GENERAL MOTORS CORP.

When brake pedal is applied, switch opens circuit to PCM/TCM. If brake switch signal is incorrect, TCC operation may be affected.

1. This step checks for voltage to brake switch.
2. This step checks if brake switch is open or faulty.
3. This step checks circuit 420 from brake switch to PCM/TCM.
4. This step simulates normal brake switch operation.