DTC C0054 BLS Off Malfunction: Wiring Diagram

WARNING: This page is about a different car, the 2012 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Stop Light Switch Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC PROCEDURE CHART

Step	Check	Yes	No
1 CHECK STOP LIGHT SWITCH. Turn the ignition switch to OFF. Disconnect the stop light switch connector. Measure the resistance of stop light switch terminals. Terminals No. 2 - No. 3:	Is the resistance 1 n or less when the switch is ON (when pedal is depressed)?	Go to step 2.	Replace the stop light switch. < Ref. to STOP LIGHT SWITCH . >
2 CHECK STOP LIGHT POWER SUPPLY. Measure the voltage between stop light switch terminal and chassis ground. Connector & terminal (B65) No. 2 (+) - Chassis ground (-):	Is the voltage 10 - 15 V?	Go to step 3.	Repair the stop light power supply circuit.
3 CHECK STOP LIGHT SWITCH HARNESS. Disconnect the connector from the VDCCM&H/U. Measure the resistance between VDCCM&H/U and stop light switch. Connector & terminal (B65) No. 3 - (B310) No. 30:	Is the resistance less than 1 Ω?	Go to step 4.	Repair the stop light switch circuit.
4 CHECK POOR CONTACT OF CONNECTORS.	Is there poor contact of connector between stop light switch and VDCCM&H/U?	Repair the connector.	Go to step 5 .
5 CHECK VDCCM&H/U. Connect all connectors. Clear the memory. < Ref. to CLEAR MEMORY MODE . > Perform the Inspection Mode. < Ref. to INSPECTION MODE . > Read the DTC.	Is the same DTC displayed?	Replace the VDCCM only. < Ref. to REPLACEMENT , VDC Control Module and Hydraulic Control Unit (VDCCM&H/U). >	Go to step 6 .
6 CHECK OTHER DTC DETECTION.	Is any other DTC displayed?	Perform the diagnosis according to DTC. < Ref. to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) . >	Temporary poor contact occurs.