DTC C0054 BLS Off Malfunction: Wiring Diagram

Fig 1: BLS Off Malfunction - Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

STOP LIGHT SWITCH DIAGNOSTIC PROCEDURE

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.	Is the resistance 0.5 Ω or less when the switch is ON (when pedal is depressed)?	Go to step 2.	Replace the stop light switch.
2 CHECK POWER SUPPLY OF STOP LIGHT SWITCH. Measure the voltage between the 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 power supply circuit of stop light.
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 0.5 Ω?	Go to step 4.	Repair the stop light switch circuit.
4 CHECK POOR CONTACT IN CONNECTORS.	Is there poor contact in 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. Refer to CLEAR MEMORY MODE . Perform the Inspection Mode. Refer to INSPECTION MODE . Read the DTC.	Is the same DTC displayed?	Replace the VDCCM only. Refer 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. Refer to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .	Temporary poor contact occurs.