P0571

DTC P0571 Brake Switch "A" Circuit

CIRCUIT DESCRIPTION

DTC Detection Condition:

The purpose of this circuit is to prevent the engine from stalling, when brakes are suddenly applied. When the brake pedal is depressed, this switch sends a signal to the ECM.

Wiring Diagram:

Step 1 - 2:

Step 2 (Continued) - 3:

INSPECTION PROCEDURE

HINT: Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, this is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.

CHECK FOR INTERMITTENT PROBLEMS

TOYOTA hand-held tester only:
By putting the vehicle's ECM in the check mode, 1 trip detection logic is possible instead of 2 trip detection logic and sensitivity to detect open circuits is increased. This makes it easier to detect intermittent problems.

1. Clear the DTC.
2. Set the check mode.
3. Perform a simulation test.
4. Check the connector and terminal.
5. Handle the connector.