DTC P0573 Brake Switch "A" Circuit High: Notes

1. - 

DTC detecting condition: 

Stop light SW1 signal of EEB control module ON stuck

Trouble symptom: 

• Regenerative brake cannot be controlled.
• Brake assist does not operate.
• EyeSight functions (ACC/PCS) do not operate.

Wiring diagram: 

Electronic controlled brake system Ref. to WIRING SYSTEM (CROSSTREK MODEL (HEV))>ELECTRIC CONTROL BRAKE SYSTEM .

Courtesy of SUBARU OF AMERICA, INC.

1. INTERVIEW CUSTOMERS  .

   Make sure that the operation was performed in which accelerator pedal and brake pedal were depressed simultaneously (with depressing brake pedal with left foot).

   Were the acceleration pedal and brake pedal depressed simultaneously?

   Yes:  System is normal. (DTC may be recorded if the brake pedal is always depressed while driving.)

   No:  Go to  2.

2. CHECK STOP LIGHT RELAY  .
   1. Turn the ignition switch to OFF.
   2. Measure the resistance of stop light relay terminals.

      Terminals 

      No. 12 - No. 13:

      Is the resistance less than 1 Ω?

      Yes:  Replace the stop light relay. Ref. to VEHICLE DYNAMICS CONTROL (VDC)>RELAY AND FUSE .

      No:  Go to  3.

3. CHECK CONNECTOR  .
   1. Disconnect the coupling connector. (AD81, B652)
   2. Check the intermediate connector.

      Is there poor contact or damage at the connector?

      Yes:  Repair or replace the intermediate connector.

      No:  Go to  4.

4. CHECK STOP LIGHT SWITCH CIRCUIT  .
   1. Turn the ignition switch to ON.
   2. Measure the voltage between stop light relay and chassis ground.
      NOTE: When stop lights are not illuminating (when brake pedal is not depressed)

      Connector & terminal 

      (B225) No. 13 (+) - Chassis ground (-):

      Is the voltage 10 V or more?

      Yes:  Repair the stop light switch circuit.

      No:  Go to  5.

5. CHECK DTC  .
   1. Using the Subaru Select Monitor, perform the clear memory of [Electric Brake Booster]. Ref. to COMMON (DIAG)>CLEAR MEMORY .
   2. Read the DTC of [Electric Brake Booster] using the Subaru Select Monitor. Ref. to ELECTRIC BRAKE BOOSTER (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

      Is DTC P0573 displayed?

      Yes:  Go to  6.

      No:  Go to  7.

6. CHECK HARNESS BETWEEN EEB CONTROL MODULE AND INTERMEDIATE CONNECTOR  .
   1. Remove brake booster assembly (with the master cylinder) from vehicle.
   2. Disconnect the EEB control module connector.
   3. Measure the resistance between EEB control module connector and intermediate connector.

      Connector & terminal 

      (AD82) No. 20 - (AD81) No. 17:

      Is the resistance less than 1 Ω?

      Yes:  Replace the brake booster assembly (with the master cylinder). Ref. to BRAKE>BRAKE BOOSTER .

      No:  Repair or replace the harness.

7. CHECK DETECTION OF OTHER DTCS FOR EBB CONTROL MODULE  .

   Read the DTC of [Electric Brake Booster] using the Subaru Select Monitor. Ref. to ELECTRIC BRAKE BOOSTER (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is any other DTC displayed?

   Yes:  Perform the diagnosis according to the DTC. Ref. to ELECTRIC BRAKE BOOSTER (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST .

   No:  Currently, it is normal. There may have been a temporary poor contact in the harness and connector or a temporary noise interference.