DTC B181C: Short In Passenger Side Airbag Variable Vent Hole Squib Circuit (To Ground)

Diagnosis start condition:

When the ignition voltage is 10 - 16 V.

DTC detecting condition:

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

Wiring diagram:

Airbag system Refer to WIRING SYSTEM>Airbag System>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

CAUTION: Before performing diagnosis, refer to "CAUTION" in "General Description". Refer to AIRBAG (DIAGNOSTICS)>General Description>CAUTION .

CHECK POOR CONTACT OF CONNECTORS .
Check for poor contact of the connectors between the airbag control module and the passenger's airbag module (variable vent hole).

Is there poor contact?

Yes : Replace the airbag harness.

No : Go to 2.
CHECK AIRBAG MAIN HARNESS (PASSENGER'S AIRBAG (VARIABLE VENT HOLE) HARNESS) (SHORTED TO GROUND) .
1. Turn the ignition switch to OFF, and wait for 60 seconds or more after disconnecting the ground terminal from the battery sensor. Refer to REPAIR CONTENTS>NOTE>BATTERY .
2. Disconnect the connector (AB46) from the roll connector.
3. Disconnect the passenger's airbag module connectors (AB83) and (AB84).
4. Disconnect the connector (AB86) from the driver's knee airbag module.
5. Disconnect the connectors (AB41, AB42, AB43) from airbag control module.
6. Using a probe, measure the resistance between connector (AB84) of the passenger's airbag (variable vent hole) and chassis ground. Refer to AIRBAG (DIAGNOSTICS)>General Description>PREPARATION TOOL>HOW TO USE PROBE .
  CAUTION: When measuring the resistance, make sure that the probe is inserted from the back side (harness side) of the connector. Also, do not insert the probe forcibly.
  
  Connector & terminal
  
  (AB84) No. 1 - Chassis ground:
  
  (AB84) No. 2 - Chassis ground:
  
  Is the resistance 1 MΩ or more?
  
  Yes : Go to 3.
  
  No : Replace the airbag main harness along with body harness.
CHECK AIRBAG CONTROL MODULE .
1. Connect the connectors (AB41, AB42, AB43) to the airbag control module.
2. Connect the connector (AB46) to the roll connector.
3. Connect the passenger's airbag module connector (AB83).
4. Connect the connector (AB86) to the driver's knee airbag module.
5. Install the ground terminal to the battery sensor and turn the ignition switch to ON. Refer to REPAIR CONTENTS>NOTE>BATTERY .
6. Execute the inspection mode. Refer to AIRBAG (DIAGNOSTICS)>Inspection Mode .
7. Read the DTC of [Airbag] using the Subaru Select Monitor. Refer to AIRBAG (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
  Is DTC B181C displayed? (Current malfunction)
  
  Yes : Replace the airbag control module. Refer to AIRBAG SYSTEM>Airbag Control Module>REMOVAL .
  
  No : Go to 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. Refer to REPAIR CONTENTS>NOTE>BATTERY .
2. Connect the passenger's airbag module (variable vent hole) connector (AB84).
3. Install the ground terminal to the battery sensor and turn the ignition switch to ON. Refer to REPAIR CONTENTS>NOTE>BATTERY .
4. Execute the inspection mode. Refer to AIRBAG (DIAGNOSTICS)>Inspection Mode .
5. Read the DTC of [Airbag] using the Subaru Select Monitor. Refer to AIRBAG (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
  Is DTC B181C displayed? (Current malfunction)
  
  Yes : Replace the passenger's airbag module. Refer to AIRBAG SYSTEM>Passenger's Airbag Module>REMOVAL .
  
  No : Go to 5.
CHECK FOR ANY OTHER DTC ON DISPLAY .
Read the DTC of [Airbag] using the Subaru Select Monitor. Refer to AIRBAG (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

Is any other DTC displayed? (Current malfunction)

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

No : Finish the diagnosis.