DTC P0719 Brake Switch "B" Circuit Low: Notes

DTC detecting condition: 

Immediately at fault recognition

Trouble symptom: 

Gear is not shifted down when climbing a hill or driving down a hill.

Wiring diagram: 

• Non-turbo model (without EyeSight and X mode)

  Stop light system Ref. to WIRING SYSTEM>Stop Light System>WIRING DIAGRAM>WITHOUT EyeSight AND X MODE .

  Fig 1: Brake Switch (B) Circuit Low Wiring Diagram (Without Eyesight And X Mode)

  Courtesy of SUBARU OF AMERICA, INC.
• Except for non-turbo model (without EyeSight and X mode)

  Stop light system Ref. to WIRING SYSTEM>Stop Light System>WIRING DIAGRAM>EXCEPT FOR MODEL WITHOUT EyeSight AND X MODE .

1. CHECK FUSE. 
   1. Turn the ignition switch to OFF.
   2. Remove the fuse (No. 8).
   3. Check the fuse.

   Is the check result OK?

   • Yes  : Go to 2. 
   • No  : Replace the fuse (No. 8). If the new fuse (No. 8) has blown out easily, repair the short circuit of harness between fuse (No. 8) and stop light switch.
2. CHECK HARNESS. 
   1. Turn the ignition switch to OFF.
   2. Disconnect the TCM connector.
   3. Disconnect the stop light switch connector.
   4. Measure the resistance between TCM connector and stop light switch connector.

      Connector & terminal 

      (B54) No. 29 - (B65) No. 2:

   Is the resistance less than 1 Ω?

   • Yes  : Go to 3. 
   • No  : Repair the open circuit of harness.
3. CHECK HARNESS. 

   Measure the resistance between the stop light switch connector and fuse (No. 8).

   Connector & terminal 

   (B65) No. 1 - fuse (No. 8):

   Is the resistance less than 1 Ω?

   • Yes  : Go to 4. 
   • No  : Repair the open circuit of harness.
4. CHECK INPUT SIGNAL FOR TCM. 
   1. Install the fuse (No. 8).
   2. Connect the stop light switch connector.
   3. Depress the brake pedal.
   4. Measure the voltage between TCM connector and chassis ground.

      Connector & terminal 

      (B54) No. 29 (+) - Chassis ground (-):

   Is the voltage 10 V or more?

   • Yes  : Go to 5. 
   • No  : Replace the stop light switch. Ref. to BRAKE>Stop Light Switch .
5. CHECK INPUT SIGNAL FOR TCM. 
   1. Connect the TCM connector.
   2. With brake pedal depressed, read the data of [Stop Light Switch] using Subaru Select Monitor.

   Is "ON" displayed?

   • Yes  : Current condition is normal. Check for poor contact in connectors or harnesses, and repair the defective part.
   • No  : Go to 6. 
6. CHECK FOR POOR CONTACT. 

   Is there poor contact in the input signal circuit of stop light switch?

   • Yes  : Repair the poor contact.
   • No  : Replace the TCM. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>Transmission Control Module (TCM) . Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>Transmission Control Module (TCM) .