DTC B2B20: Passenger's Door Power Window Auto Switch Stuck

DTC detecting condition: 

When AUTO terminal input ON is received for 20±1 seconds or longer.

Trouble symptom: 

When the power window sub-switch is operated, passenger's side window does not work.

Wiring diagram: 

Power window system Ref. to WIRING SYSTEM (IMPREZA MODEL)>POWER WINDOW SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (EXCEPT FOR HEV))>POWER WINDOW SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (HEV))>POWER WINDOW SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK MALFUNCTIONS  .
   1. Turn the ignition switch to ON.
   2. Operate the power window main switch and check that the power window (passenger's side) operates.

   Does the power window operate normally according to switch operation?

   Yes:  Even if DTC is displayed, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

   NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.

   No:  Go to  2.

2. CHECK [One's Seat Switch] (DATA MONITOR)  .

   Using the Subaru Select Monitor, check the following items in the [Data Monitor] of [Power Window (Passenger)]. Ref. to POWER WINDOW (DIAGNOSTICS)>DATA MONITOR .

   • One's Seat Switch

   Does the display change corresponding to the switch operation?

   Yes:  Replace the front regulator and motor assembly (passenger's side). Ref. to GLASS/WINDOW/MIRRORS>FRONT REGULATOR AND MOTOR ASSEMBLY .

   No:  Go to  3.

3. CHECK FRONT POWER WINDOW SUB-SWITCH UNIT  .
   1. Turn the ignition switch to OFF.
   2. Perform the inspection of front power window sub-switch unit. Ref. to GLASS/WINDOW/MIRRORS>POWER WINDOW CONTROL SWITCH .

   Is the check result OK?

   Yes:  Go to  4.

   No:  Replace the front power window sub-switch. Ref. to GLASS/WINDOW/MIRRORS>POWER WINDOW CONTROL SWITCH .

4. CHECK HARNESS (GROUND SHORT CIRCUIT)  .
   1. Disconnect the front power window sub-switch connector.
   2. Disconnect the front regulator and motor assembly (passenger's side) connector.
   3. Using a tester, measure the resistance between the front power window sub-switch connector and chassis ground.

      Connector and terminal 

      (D17) No. 1 - Chassis ground:

   Is the resistance 1 MΩ or more?

   Yes:  Replace the front regulator and motor assembly (passenger's side). Ref. to GLASS/WINDOW/MIRRORS>FRONT REGULATOR AND MOTOR ASSEMBLY .

   No:  Repair the short circuit to ground in harness between front power window subswitch connector and front regulator and motor assembly (passenger's side) connector.