DTC P0572: Brake Switch "A" [Stop Lamp Switch] Circuit Low: Wiring Diagram

WARNING: This page is about a different car, the 2015 Subaru XV Crosstrek. However, it is still accessible from the selected car via links, so may be relevant.

Stop light system < Ref. to WIRING DIAGRAM , Stop Light System.>

Fig 1: Stop Lamp Switch Circuit - Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

DTC PROCEDURE

Step	Check	Yes	No
1 CHECK STOP LIGHT & BRAKE SWITCH. Check the stop light & brake switch. < Ref. to STOP LIGHT & BRAKE SWITCH .>	Is the stop light & brake switch and installation position OK?	Go to step 2 .	Replace the stop light & brake switch. Or adjust the installation position.
2 CHECK STOP LIGHT & BRAKE SWITCH CIRCUIT. Turn the ignition switch to OFF. Disconnect the stop light & brake switch connector. Turn the ignition switch to ON. Measure the voltage between the stop light & brake switch connector and chassis ground. Connector & terminal (B65) No. 3 (+) - Chassis ground (-):	Is the voltage 10 V or more?	Go to step 3 .	Check fuse No. 8 (in fuse & relay box). Check for open or short in the harness between stop light & brake switch and fuse & relay box.
3 CHECK STOP LIGHT & BRAKE SWITCH CIRCUIT. Turn the ignition switch to OFF. Disconnect the ECM connector. Measure the resistance between the ECM connector and stop light & brake switch connector. Connector & terminal (B137) No. 7 - (B65) No. 4:	Is the resistance less than 10 Ω?	Replace the ECM. < Ref. to ENGINE CONTROL MODULE (ECM) .>	Repair the open circuit of harness between ECM connector and stop light & brake switch connector.