DTC B1805: Short In Passenger's Airbag

Diagnosis start condition: 

When the ignition voltage is 10 - 16 V.

DTC detecting condition: 

• Airbag main harness circuit is shorted.
• Airbag module harness circuit (passenger's side) is shorted.
• Passenger's airbag module is faulty.
• Airbag control module is faulty.

Wiring diagram: 

Airbag system Ref. to WIRING SYSTEM (IMPREZA MODEL)>AIRBAG SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (EXCEPT FOR HEV))>AIRBAG SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (HEV))>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 HARNESS)  .
   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 REPAIR CONTENTS>REPAIR CONTENTS>NOTE>BATTERY .
      NOTE: For the hybrid model, turn the ignition switch to OFF, and wait for 60 seconds or more after disconnecting the ground terminal from the battery.
   2. Disconnect the connectors (AB7) and (AB2).
   3. Disconnect the connector (AB66) from the driver's knee airbag module.
   4. Disconnect the connectors (AB6, AB17, AB18) from airbag control module.
   5. Connect the connectors (AB6, AB17, AB18) to the connector (1AG) in the test harness AG, and disengage the short mechanism of the connectors (AB6, AB17, AB18).
   6. Disconnect the passenger's airbag module connector (AB9).
   7. Using a probe, measure the resistance between the terminals of connector (AB9). Ref. 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 

      (AB9) No. 1 - (AB9) No. 2:

   Is the resistance 1 MΩ or more?

   Yes  : Go to  3.

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

3. CHECK AIRBAG CONTROL MODULE  .
   1. Disconnect the test harness AG from the connectors (AB6, AB17, AB18).
   2. Connect the connectors (AB6, AB17, AB18) and the airbag control module.
   3. Connect the connectors (AB7) and (AB2).
   4. Connect the connector (AB66) to the driver's knee airbag module.
   5. Install the ground terminal to the battery sensor and turn the ignition switch to ON. Ref. to REPAIR CONTENTS>REPAIR CONTENTS>NOTE>BATTERY .
      NOTE: For the hybrid model, connect the battery ground terminal and turn the ignition switch to ON.
   6. Execute the inspection mode. Ref. to AIRBAG (DIAGNOSTICS)>INSPECTION MODE .
   7. Read the DTC of [Airbag] using the Subaru Select Monitor. Ref. to AIRBAG (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC B1805 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  .
   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 REPAIR CONTENTS>REPAIR CONTENTS>NOTE>BATTERY .
      NOTE: For the hybrid model, turn the ignition switch to OFF, and wait for 60 seconds or more after disconnecting the ground terminal from the battery.
   2. Connect the passenger's airbag module connector (AB9).
   3. Install the ground terminal to the battery sensor and turn the ignition switch to ON. Ref. to REPAIR CONTENTS>REPAIR CONTENTS>NOTE>BATTERY .
      NOTE: For the hybrid model, connect the battery ground terminal and turn the ignition switch to ON.
   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 B1805 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.