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HOMESERVICE MANUALSSUBARU2016LEGACY 2.5IREPAIR AND DIAGNOSISBRAKESTRACTION CONTROLVEHICLE DYNAMICS CONTROL (VDC) SYSTEM (DIAGNOSTICS)DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)DTC C1531 BLS OFF STUCKWIRING DIAGRAM
2016 Subaru Legacy 2.5i

DTC C1531 BLS Off Stuck: Wiring Diagram

2016 Subaru Legacy 2.5iSECTION Wiring Diagram

Vehicle dynamics control system < Ref. to appropriate wiring diagram in SYSTEM WIRING DIAGRAM article. >

Fig 1: BLS OFF Stuck - Wiring Diagram
G10311126Courtesy of SUBARU OF AMERICA, INC.
DIAGNOSTIC PROCEDURE

Step Check Yes No
1 CHECK STOP LIGHT. 
  1. Turn the ignition switch to OFF.
  2. Check the stop light. < Ref. to STOP LIGHT SYSTEM . >
 Are the stop lights OK? Go to step 2  . Replace the stop lights. < Ref. to STOP LIGHT SYSTEM . >
2 CHECK STOP LIGHT SWITCH. 
Check the stop light switch. < Ref. to INSTALLATION , Stop Light Switch. >		 Is the installation position of the stop light switch correct? Go to step 3  . Adjust the installation position of the stop light switch. < Ref. to INSTALLATION , Stop Light Switch. >
3 CHECK STOP LIGHT SWITCH. 
  1. Disconnect the stop light switch connector.
  2. Measure the resistance of stop light switch terminals.

    Terminals 

    No. 1 - No. 2: 

 Is the resistance less than 1 Ω when the stop light switch is ON (when pedal is depressed)? Go to step 4  . Replace the stop light switch. < Ref. to STOP LIGHT SWITCH . >
4 CHECK STOP LIGHT RELAY. 
Measure the resistance of stop light relay terminals.
Terminals 
No. 12 - No. 15: 		 Is the resistance less than 1 Ω? Go to step 5  . Replace the stop light relay.
5 CHECK VDCCM & H/U CONNECTOR. 
Disconnect the connector from the VDCCM & H/U.		 Is there poor contact or damage of the VDCCM & H/U connector? Repair the VDCCM & H/U connector. Go to step 6  .
6 CHECK STOP LIGHT SWITCH CIRCUIT (CHECK FOR OPEN CIRCUIT). 
Measure the resistance of stop light switch circuit.
Connector & terminal 
(B310) No. 17 - (B48) No. 15: 
(B65) No. 2 - (B48) No. 12: 
(B65) No. 1 - (F/B fuse) No. 37: 		 Is the resistance less than 1 Ω? Go to step 7  . Repair the stop light switch circuit.
7 CHECK STOP LIGHT SWITCH CIRCUIT. 
  1. Connect all connectors.
  2. Turn the ignition switch to ON.
  3. Measure the voltage between stop light relay and chassis ground.

    Connector & terminal 

    (B48) No. 15 (+) - Chassis ground (-): 

 Is the voltage 10 V or more when the stop light switch is ON (when pedal is depressed)? Go to step 8  . Repair the stop light switch circuit.
8 CHECK VDCCM & H/U. 
  1. Perform the Clear Memory Mode. < Ref. to CLEAR MEMORY MODE . >
  2. Perform the Inspection Mode. < Ref. to INSPECTION MODE . >
  3. Read the DTC. < Ref. to READ DIAGNOSTIC TROUBLE CODE (DTC) . >
 Is the same DTC displayed? Replace the VDCCM & H/U. < Ref. to VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM & H/U) . > Go to step 9  .
9 CHECK DETECTION OF OTHER DTCS FOR VDC. 
< Ref. to READ DIAGNOSTIC TROUBLE CODE (DTC) . >		 Is any other DTC displayed? Perform the diagnosis according to DTC. < Ref. to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) . > Currently, it is normal. There may have been a poor contact in the harness and connector or a temporarily noise interference.
RENDER: 1.0x

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