DTC B1837: Short In Curtain Airbag LH Squib Circuit (To Ground)

Diagnosis start condition:

When the ignition voltage is 10 - 16 V.

DTC detecting condition:

Curtain airbag harness LH circuit is shorted to ground.
Curtain airbag module LH 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 curtain airbag module LH.

Is there poor contact?

Yes : Replace the airbag rear harness along with body harness.

No : Go to 2.
CHECK CURTAIN AIRBAG MODULE .
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 (AB92) from curtain airbag module LH.
3. Connect the connector (1N) in the test harness N to the connector (AB92).
4. Connect the airbag resistor to the connector (2N) of test harness N.
5. Install the ground terminal to the battery sensor and turn the ignition switch to ON. Refer to REPAIR CONTENTS>NOTE>BATTERY .
  Does the airbag warning light illuminate for six seconds and go off?
  
  Yes : Replace the curtain airbag module LH. Refer to AIRBAG SYSTEM>Curtain Airbag Module .
  
  No : Go to 3.
CHECK AIRBAG REAR HARNESS (CURTAIN AIRBAG MODULE HARNESS LH) (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 (AB94) from seat belt pretensioner LH.
3. Disconnect the connector (AB98) from the adaptive force limiter LH.
4. Disconnect the connector (AB96) from lap seat belt pretensioner LH.
5. Disconnect the connector (AB100) from rear seat belt pretensioner LH.
6. Disconnect the connector (AB88) from side airbag module LH.
7. Disconnect the airbag resistor from test harness N.
8. Disconnect the connectors (AB41, AB42, AB43) from airbag control module.
9. Connect the connector (1BF) in the test harness BF to the connectors (AB41, AB42, AB43).
10. Measure the resistance between connector (7BF) in the test harness BF and chassis ground.
  Connector & terminal
  
  (7BF) No. 1 - Chassis ground:
  
  (7BF) No. 6 - Chassis ground:
  
  Is the resistance 1 MΩ or more?
  
  Yes : Go to 4.
  
  No : Replace the airbag rear harness along with body harness.
CHECK AIRBAG CONTROL MODULE .
1. Disconnect the test harness BF from the connectors (AB41, AB42, AB43).
2. Connect all connectors.
3. Using the Subaru Select Monitor, perform the clear memory of [Airbag]. Refer to COMMON (DIAG)>CLEAR MEMORY .
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 B1837 displayed? (Current malfunction)
  
  Yes : Replace the airbag control module. Refer to AIRBAG SYSTEM>AIRBAG CONTROL MODULE .
  
  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.