DTC B1697: Lost Communication With Door Sensor LH

Diagnosis start condition: 

When the ignition voltage is 10 - 16 V.

DTC detecting condition: 

• Open or short circuit in harness of Side impact sensor LH (front door)
• Side impact sensor LH (front door) 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 (AB41, L51, Df12, AB62) between the airbag control module and Side impact sensor LH (front door).

   Is there poor contact?

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

   No  : Go to  2.

2. CHECK AIRBAG REAR HARNESS AND DOOR HARNESS (BETWEEN AIRBAG CONTROL MODULE AND Side impact sensor LH (front door)) (OPEN CIRCUIT)  .
   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>NOTE>BATTERY
   2. Disconnect the connector (AB94) from seat belt pretensioner LH.
   3. Disconnect the connector (AB100) from rear seat belt pretensioner LH.
   4. Disconnect the connector (AB88) from side airbag module LH.
   5. Disconnect the connector (AB92) from curtain airbag module LH.
   6. Disconnect the connectors (AB41, AB42, AB43) from airbag control module.
   7. Connect the connector (1BF) in the test harness BF to the connectors (AB41, AB42, AB43).
   8. Disconnect the connector (AB62) from Side impact sensor LH (front door).
   9. Connect the connector (1BG) in the test harness BG to the connector (AB62).
   10. Measure the resistance between connector (6BF) in the test harness BF and connector (2BG) in the test harness BG.

       Connector & terminal 

       (6BF) No. 8 - (2BG) No. 2:

       (6BF) No. 3 - (2BG) No. 1:

   Is the resistance less than 10 Ω?

   Yes  : Go to  3.

   No  : Check the door harness, and if any fault is found, replace the harness. If there is no fault, replace the airbag rear harness together with body harness.

3. CHECK AIRBAG REAR HARNESS AND DOOR HARNESS (BETWEEN AIRBAG CONTROL MODULE AND Side impact sensor LH (front door)) (SHORTED TO GROUND AND SHORTED BETWEEN LINES)  .

   Measure the resistance between connector (6BF) in the test harness BF and chassis ground, and the resistance between connector (6BF) terminals in the test harness BF.

   Connector & terminal 

   (6BF) No. 8 - Chassis ground:

   (6BF) No. 3 - Chassis ground:

   (6BF) No. 8 - (6BF) No. 3:

   Is the resistance 1 MΩ or more?

   Yes  : Go to  4.

   No  : Check the door harness, and if any fault is found, replace the harness. If there is no fault, replace the airbag rear harness together with body harness.

4. CHECK AIRBAG CONTROL MODULE  .
   1. Disconnect all test harnesses.
   2. Connect all connectors.
   3. Install the ground terminal to the battery sensor and turn the ignition switch to ON. Ref. to REPAIR CONTENTS>NOTE>BATTERY
   4. Using the Subaru Select Monitor, perform the clear memory of [Airbag]. Ref. to COMMON (DIAGNOSTICS)>CLEAR MEMORY
   5. Execute the inspection mode. Ref. to AIRBAG (DIAGNOSTICS)>INSPECTION MODE 
   6. Read the DTC of [Airbag] using the Subaru Select Monitor. Ref. to AIRBAG (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) 

   Is DTC B1697 or B1698 displayed? (Current code)

   Yes  : Replace Side impact sensor LH (front door). Ref. to AIRBAG SYSTEM>IMPACT SENSOR>REMOVAL>SIDE IMPACT SENSOR (FRONT DOOR) Replace the airbag control module if not operating normally even after replacing the sensor. Ref. to AIRBAG SYSTEM>AIRBAG CONTROL MODULE>REMOVAL

   No  : Finish the diagnosis.