DTC B1870: Short In Front Seat Cushion Airbag RH

Diagnosis start condition:

When the ignition voltage is 10 - 16 V.

DTC detecting condition:

Shorted between +/- lines (shorted between rear harness lines, shorted between front seat cushion airbag RH lines, shorted between airbag Control Module internal lines)

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 seat cushion airbag module RH.

Is there poor contact?

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

No : Go to 2.
CHECK SEAT CUSHION 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 (AB89) from the seat cushion airbag module RH, and connect the connector (1D) in the test harness D to connector (AB89).
3. Connect the airbag resistor to connector (3D) in the test harness D.
4. 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 seat cushion airbag module RH. Refer to AIRBAG SYSTEM>Seat Cushion Airbag Module .
  
  No : Go to 3.
CHECK AIRBAG REAR HARNESS (SEAT CUSHION AIRBAG MODULE HARNESS RH) (SHORTED BETWEEN LINES) .
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 (AB93) from seat belt pretensioner RH.
3. Disconnect the connector (AB97) from the adaptive force limiter RH.
4. Disconnect the connector (AB99) from Rear seatbelt pretensioner RH.
5. Disconnect the connector (AB87) from side airbag module RH.
6. Disconnect the connector (AB91) from curtain airbag module RH.
7. Disconnect the airbag resistor from test harness D.
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 (3D) terminals in test harness D.
  Connector & terminal
  
  (3D) No. 3 - (3D) No. 4:
  
  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 B1870 displayed?
  
  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.