DTC B1642: Side Satellite Sensor Bus RH Lost Communication

Diagnosis start condition:

When the ignition voltage is 10 - 16 V.

DTC detecting condition:

Open or short circuit in harness of Side impact sensor RH (center pillar)
Side impact sensor RH (center pillar) is faulty.
Open or short circuit in harness of Side impact sensor RH (rear wheel house)
Side impact sensor RH (rear wheel house) is faulty.
Open or short circuit in harness of Side impact sensor RH (front door)
Side impact sensor RH (front door) is faulty.
Airbag control module is faulty.

Failure detection pattern:

"Primary" (high-priority diagnosis)

Warning light/indicator light:

Airbag warning light◦

Wiring diagram:

Airbag system Ref. to WIRING SYSTEM>AIRBAG SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

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

CHECK DTC .
Read the DTC of [Airbag] using the Subaru Select Monitor. Ref. to AIRBAG (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

Is DTC B1622 or B1623 displayed? (Current code)

Yes: Perform the diagnosis for the displayed DTC B1622 or B1623. Ref. to AIRBAG (DIAGNOSTICS)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC B1622 SIDE AIRBAG SENSOR RH LOST COMMUNICATION . AIRBAG (DIAGNOSTICS)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC B1623 SIDE AIRBAG SENSOR RH INITIALIZATION ERROR .

No: GO TO 2.
CHECK DTC .
Read the DTC of [Airbag] using the Subaru Select Monitor. Ref. to AIRBAG (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

Is DTC B1632 or B1633 displayed? (Current code)

Yes: Perform the diagnosis for the displayed DTC B1632 or B1633. Ref. to AIRBAG (DIAGNOSTICS)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC B1632 CURTAIN AIRBAG SENSOR RH LOST COMMUNICATION . AIRBAG (DIAGNOSTICS)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC B1633 CURTAIN AIRBAG SENSOR RH INITIALIZATION ERROR .

No: GO TO 3.
CHECK DTC .
Read the DTC of [Airbag] using the Subaru Select Monitor. Ref. to AIRBAG (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

Is DTC B1692 or B1693 displayed? (Current code)

Yes: Perform the diagnosis for the displayed DTC B1692 or B1693. Ref. to AIRBAG (DIAGNOSTICS)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC B1692 LOST COMMUNICATION WITH DOOR SENSOR RH . AIRBAG (DIAGNOSTICS)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC B1693 DOOR SENSOR RH INITIALIZATION INCOMPLETE .

No: GO TO 4.
CHECK POOR CONTACT OF CONNECTORS .
Check for poor contact of the connectors between the airbag control module and Side impact sensor RH (front door).

Is there poor contact?

Yes: Replace the airbag rear harness and the door harness.

No: GO TO 5.
CHECK AIRBAG REAR HARNESS (BETWEEN AIRBAG CONTROL MODULE AND Side impact sensor RH (center pillar)) (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 (AB93) from seat belt pretensioner RH.
3. Disconnect the connector (AB99) from Rear seatbelt pretensioner RH.
4. Disconnect the connector (AB89) from seat cushion airbag module RH.
5. Disconnect the connector (AB87) from side airbag module RH.
6. Disconnect the connector (AB91) from curtain airbag module RH.
7. Disconnect the connectors (AB41, AB42, AB43) from airbag control module.
8. Connect the connector (1BF) in the test harness BF to the connectors (AB41, AB42, AB43).
9. Disconnect the connector (AB55) from Side impact sensor RH (center pillar).
10. Connect the connector (1BH) in the test harness BH to the connector (AB55).
11. Measure the resistance between connector (4BF) in the test harness BF and connector (2BH) in the test harness BH.
  Connector & terminal
  
  (4BF) No. 1 - (2BH) No. 2:
  
  (4BF) No. 5 - (2BH) No. 1:
Is the resistance less than 10 Ω?

Yes: GO TO 6.

No: Replace the airbag rear harness along with body harness.
CHECK AIRBAG REAR HARNESS (BETWEEN AIRBAG CONTROL MODULE AND Side impact sensor RH (center pillar)) (SHORTED TO GROUND AND SHORTED BETWEEN LINES) .
Measure the resistance between connector (4BF) in the test harness BF and chassis ground, and the resistance between connector (4BF) terminals in the test harness BF.

Connector & terminal

(4BF) No. 1 - Chassis ground:

(4BF) No. 5 - Chassis ground:

(4BF) No. 1 - (4BF) No. 5:

Is the resistance 1 MΩ or more?

Yes: GO TO 7.

No: Replace the airbag rear harness along with body harness.
CHECK AIRBAG REAR HARNESS (BETWEEN AIRBAG CONTROL MODULE AND Side impact sensor RH (rear wheel house)) (OPEN CIRCUIT) .
1. Disconnect the connector (AB57) from Side impact sensor RH (rear wheel house).
2. Connect the connector (1BH) in the test harness BH to the connector (AB57).
3. Measure the resistance between connector (4BF) in the test harness BF and connector (2BH) in the test harness BH.
  Connector & terminal
  
  (4BF) No. 6 - (2BH) No. 1:
  
  (4BF) No. 2 - (2BH) No. 2:
Is the resistance less than 10 Ω?

Yes: GO TO 8.

No: Replace the airbag rear harness along with body harness.
CHECK AIRBAG REAR HARNESS (BETWEEN AIRBAG CONTROL MODULE AND Side impact sensor RH (rear wheel house)) (SHORTED TO GROUND AND SHORTED BETWEEN LINES) .
Measure the resistance between connector (4BF) in the test harness BF and chassis ground, and the resistance between connector (4BF) terminals in the test harness BF.

Connector & terminal

(4BF) No. 6 - Chassis ground:

(4BF) No. 2 - Chassis ground:

(4BF) No. 6 - (4BF) No. 2:

Is the resistance 1 MΩ or more?

Yes: GO TO 9.

No: Replace the airbag rear harness along with body harness.
CHECK AIRBAG REAR HARNESS AND DOOR HARNESS (BETWEEN AIRBAG CONTROL MODULE AND Side impact sensor RH (front door)) (OPEN CIRCUIT) .
1. Disconnect the connector (AB61) from Side impact sensor RH (front door).
2. Connect the connector (1H) in the test harness H to the connector (AB61).
3. Measure the resistance between connector (4BF) in the test harness BF and connector (3H) in the test harness H.
  Connector & terminal
  
  (4BF) No. 7 - (3H) No. 6:
  
  (4BF) No. 3 - (3H) No. 5:
Is the resistance less than 10 Ω?

Yes: GO TO 10.

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.
CHECK AIRBAG REAR HARNESS AND DOOR HARNESS (BETWEEN AIRBAG CONTROL MODULE AND Side impact sensor RH (front door)) (SHORTED TO GROUND AND SHORTED BETWEEN LINES) .
Measure the resistance between connector (4BF) in the test harness BF and chassis ground, and the resistance between connector (4BF) terminals in the test harness BF.

Connector & terminal

(4BF) No. 7 - Chassis ground:

(4BF) No. 3 - Chassis ground:

(4BF) No. 7 - (4BF) No. 3:

Is the resistance 1 MΩ or more?

Yes: GO TO 11.

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.
CHECK AIRBAG CONTROL MODULE .
1. Disconnect all test harnesses.
2. Connect all connectors.
3. Using the Subaru Select Monitor, perform the clear memory of [Airbag]. Ref. to COMMON (DIAGNOSTICS)>CLEAR MEMORY .
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 B1642 displayed? (Current code)

Yes: GO TO 12.

No: Finish the diagnosis.
REPLACE Side impact sensor RH (center pillar) AND CHECK AIRBAG CONTROL MODULE AFTER REPLACEMENT .
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. Replace Side impact sensor RH (center pillar). Ref. to AIRBAG SYSTEM>IMPACT SENSOR>REMOVAL .
3. Connect all connectors.
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 B1642 displayed? (Current code)

Yes: GO TO 13.

No: Finish the diagnosis.
REPLACE Side impact sensor RH (rear wheel house) AND CHECK AIRBAG CONTROL MODULE AFTER REPLACEMENT .
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. Replace Side impact sensor RH (rear wheel house). Ref. to AIRBAG SYSTEM>IMPACT SENSOR>REMOVAL .
3. Connect all connectors.
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 B1642 displayed? (Current code)

Yes: GO TO 14.

No: Finish the diagnosis.
REPLACE Side impact sensor RH (front door) AND CHECK AIRBAG CONTROL MODULE AFTER REPLACEMENT .
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. Replace Side impact sensor RH (front door). Ref. to AIRBAG SYSTEM>IMPACT SENSOR>REMOVAL .
3. Connect all connectors.
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 B1642 displayed? (Current code)

Yes: Replace the airbag control module. Ref. to AIRBAG SYSTEM>AIRBAG CONTROL MODULE>REMOVAL .

No: Finish the diagnosis.