P0703

DTC P0703: Brake Switch Circuit Malfunction





Circuit Description
The brake switch is used to indicate brake pedal status to the Transaxle Control Module (TCM). The brake switch is a normally open switch. Applying the brake pedal closes the switch, supplying voltage to the TCM. Releasing the brake pedal interrupts voltage to the TCM.

NOTE: If the brake pedal was applied prior to or during the connection of the scan tool to the vehicle, P0703 will be disappeared. If the system is operating normally, the code will then be deleted once the brake pedal is applied with the scan tool connected.

This DTC is stored at start-up. If the TCM receives a brake switch signal after start-up, the DTC will be stored in memory.

Conditions for Setting the DTC
- Brake switch stuck to closed.
- Brake switch wiring harness shortage to ground.
- Brake switch wiring harness shortage to power.
- Immediately after the above condition occurs.

Action Taken When the DTC Sets
- No lamp control required but diagnostic information should be stored immediately when malfunction is detected.
- TCM assume that the brake light always active.

Conditions for Clearing the MIL/DTC
Using a scan tool can clear history DTCs.

Diagnostic Aids
- Inspect the poor wiring harness connection for TCM connectors and transaxle wiring connectors.
- Inspect the improperly formed or damage terminals.

Troubleshooting