DTC C1922: Hill Hold Switch Circuit

DTC Detecting condition: 

A fault is detected if the hill hold switch is pressed and held for a long period of time.

Trouble symptom: 

Hill hold function cannot be set.

Wiring diagram: 

Parking brake/brake fluid level warning light system Ref. to WIRING SYSTEM (CROSSTREK MODEL (HEV))>PARKING BRAKE/BRAKE FLUID LEVEL WARNING LIGHT SYSTEM .

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK HILL HOLD SWITCH POWER SUPPLY  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the connector from hill hold switch.
   3. Turn the ignition switch to ON.
   4. Measure the voltage between hill hold switch connector and chassis ground.

      Connector and terminal 

      (i156) No. 6 (+) - Chassis ground (-):

   Is the voltage 10 - 15 V?

   Yes:  Go to  2.

   No:  Repair the power supply circuit of hill hold switch.

2. CHECK HARNESS (CHECK FOR OPEN CIRCUIT)  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the connector from the VDCCM and H/U.
   3. Measure the resistance between VDCCM and H/U and hill hold switch connector.

      Connector and terminal 

      (i156) No. 8 - (B310) No. 24:

   Is the resistance less than 1 Ω?

   Yes:  Go to  3.

   No:  Repair harness and connector between VDCCM and H/U and hill hold switch connector.

3. CHECK HARNESS (CHECK FOR GROUND SHORT CIRCUIT)  .

   Measure the resistance between hill hold switch connector and chassis ground.

   Connector and terminal 

   (i156) No. 8 - Chassis ground:

   Is the resistance 1 MΩ or more?

   Yes:  Go to  4.

   No:  Repair ground short of harness between VDCCM and H/U and hill hold switch connector.

4. CHECK HARNESS (CHECK FOR SHORT CIRCUIT TO POWER SUPPLY)  .
   1. Turn the ignition switch to ON.
   2. Measure the voltage between hill hold switch connector and chassis ground.

      Connector and terminal 

      (i156) No. 8 (+) - Chassis ground (-):

   Is the voltage less than 1 V?

   Yes:  Go to  5.

   No:  Repair short to power supply of harness between VDCCM and H/U and hill hold switch connector.

5. CHECK HILL HOLD SWITCH  .

   Check the hill hold switch. Ref. to VEHICLE DYNAMICS CONTROL (VDC)>HILL HOLD SWITCH .

   Is the check result OK?

   Yes:  Go to  6.

   No:  Replace the hill hold switch. Ref. to VEHICLE DYNAMICS CONTROL (VDC)>HILL HOLD SWITCH .

6. CHECK VDCCM and H/U  .
   1. Connect all connectors.
   2. Using the Subaru Select Monitor, perform the clear memory of [Brake Control]. Ref. to COMMON (DIAG)>CLEAR MEMORY .
   3. Execute the inspection mode. Ref. to BRAKE CONTROL (DIAGNOSTICS) (HEV)>INSPECTION MODE .
   4. Read the DTC of [Brake Control] using the Subaru Select Monitor. Ref. to BRAKE CONTROL (DIAGNOSTICS) (HEV)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is the same DTC displayed?

   Yes:  Replace the VDCCM and H/U. Ref. to VEHICLE DYNAMICS CONTROL (VDC)>VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM & H/U) .

   No:  Go to  7.

7. CHECK DETECTION OF OTHER DTCS FOR VDC  .

   Read the DTC of [Brake Control] using the Subaru Select Monitor. Ref. to BRAKE CONTROL (DIAGNOSTICS) (HEV)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is any other DTC displayed?

   Yes:  Perform the diagnosis according to the DTC. Ref. to BRAKE CONTROL (DIAGNOSTICS) (HEV)>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.