DTC B181D: Short In Passenger Side Airbag Variable Vent Hole Squib Circuit (To +B)

Diagnosis start condition: 

When the ignition voltage is 10 - 16 V.

DTC detecting condition: 

• Airbag main harness circuit is shorted to power supply.
• Airbag module harness (passenger's side) circuit is shorted to power supply.
• Passenger's airbag module (variable vent hole) is faulty.
• Airbag control module is faulty.

Wiring diagram: 

Airbag system Ref. to WIRING SYSTEM>AIRBAG SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK POOR CONTACT OF CONNECTORS  .

   Check for poor contact of the connectors between the airbag control module and the passenger's airbag module.

   Is there poor contact?

   Yes  : Replace the airbag harness.

   No  : Go to  2 .

2. CHECK AIRBAG MAIN HARNESS (PASSENGER'S AIRBAG (VARIABLE VENT HOLE) HARNESS) (SHORTED TO POWER SUPPLY)  .
   1. Turn the ignition switch to OFF, and wait for 60 seconds or more after disconnecting the ground terminal from the battery sensor Ref. to GROUND TERMINAL REMOVAL OR INSTALLATION .
   2. Disconnect the connector (AB2) from the roll connector.
   3. Disconnect the passenger's airbag module connectors (AB9) and (AB27).
   4. Disconnect the connector (AB66) from the driver's knee airbag module.
   5. Disconnect the connectors (AB6, AB17, AB18) from airbag control module.
   6. Install the ground terminal to the battery sensor and turn the ignition switch to ON. Ref. to GROUND TERMINAL REMOVAL OR INSTALLATION .
   7. Measure the voltage between connector (AB27) of the passenger's airbag (variable vent hole) and chassis ground. Ref. to AIRBAG (DIAGNOSTICS)>General Description>PREPARATION TOOL>HOW TO USE PROBE .
      CAUTION: Connect the test harness AT terminal to the connector (AB27) terminal and contact a tester to the test harness AT.

      Connector and terminal 

      (AB27) No. 1 (+) - Chassis ground (-):

      (AB27) No. 2 (+) - Chassis ground (-):

   Is the voltage less than 1 V?

   Yes  : Go to  3 .

   No  : Replace the airbag main harness along with body harness.

3. CHECK AIRBAG CONTROL MODULE  .
   1. Turn the ignition switch to OFF, and wait for 60 seconds or more after disconnecting the ground terminal from the battery sensor. Ref. to GROUND TERMINAL REMOVAL OR INSTALLATION .
   2. Connect the connectors (AB6, AB17, AB18) and the airbag control module.
   3. Connect the connector (AB2) to the roll connector.
   4. Connect the passenger's airbag module connector (AB9).
   5. Connect the connector (AB66) to the driver's knee airbag module.
   6. Install the ground terminal to the battery sensor and turn the ignition switch to ON. Ref. to GROUND TERMINAL REMOVAL OR INSTALLATION .
   7. Execute the inspection mode. Ref. to AIRBAG (DIAGNOSTICS)>INSPECTION MODE .
   8. Read the DTC of [Airbag] using the Subaru Select Monitor. Ref. to AIRBAG (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC B181D displayed? (Current malfunction)

   Yes  : Replace the airbag control module. Ref. to AIRBAG SYSTEM>AIRBAG CONTROL MODULE>REMOVAL .

   No  : Go to  4 .

4. CHECK PASSENGER'S AIRBAG MODULE (VARIABLE VENT HOLE)  .
   1. Turn the ignition switch to OFF, and wait for 60 seconds or more after disconnecting the ground terminal from the battery sensor. Ref. to GROUND TERMINAL REMOVAL OR INSTALLATION .
   2. Connect the passenger's airbag module (variable vent hole) connector (AB27).
   3. Install the ground terminal to the battery sensor and turn the ignition switch to ON. Ref. to GROUND TERMINAL REMOVAL OR INSTALLATION .
   4. Execute the inspection mode. Ref. to AIRBAG (DIAGNOSTICS)>INSPECTION MODE .
   5. Read the DTC of [Airbag] using the Subaru Select Monitor. Ref. to AIRBAG (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC B181D displayed? (Current malfunction)

   Yes  : Replace the passenger's airbag module. Ref. to AIRBAG SYSTEM>PASSENGER'S AIRBAG MODULE>REMOVAL .

   No  : Go to  5 .

5. CHECK FOR ANY OTHER DTC ON DISPLAY  .

   Read the DTC of [Airbag] using the Subaru Select Monitor. Ref. to AIRBAG (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is any other DTC displayed? (Current malfunction)

   Yes  : Perform the diagnosis for other displayed DTCs. Ref. to AIRBAG (DIAGNOSTICS)>Diagnostic Trouble Code (DTC)>LIST .

   No  : Finish the diagnosis.