Subaru Legacy BN/BS (2015-2019) Service Manual: Dtc b1627 side airbag sensor lh lost communication

Subaru Legacy BN/BS (2015-2019) Service Manual / Airbag system (diagnostics) / Diagnostic chart with trouble code / Dtc b1627 side airbag sensor lh lost communication

DIAGNOSIS START CONDITION:

Ignition voltage is 10 V to 16 V.

DTC DETECTING CONDITION:

Side airbag sensor LH communication error (open/short circuit or connector connection failure between airbag CM and sensor, sensor internal communication circuit failure, CM internal communication circuit failure)

CAUTION:

Before performing diagnosis, refer to “CAUTION” in “General Description”. General Description > CAUTION

WIRING DIAGRAM:

NOTE:

For the coupling connector, refer to “WIRING SYSTEM”.

Airbag system Airbag System > WIRING DIAGRAM

STEP	CHECK	YES	NO
1.CHECK POOR CONTACT OF CONNECTORS. Check for poor contact of the connectors between the airbag control module and the side airbag sensor LH.	Is there poor contact-	Replace the airbag main harness along with body harness.	Diagnostic Chart with Trouble Code > DTC B1627 SIDE AIRBAG SENSOR LH LOST COMMUNICATION
2.CHECK AIRBAG REAR HARNESS (BETWEEN AIRBAG CONTROL MODULE AND SIDE AIRBAG SENSOR LH) (OPEN CIRCUIT). 1) Turn the ignition switch to OFF, disconnect the battery ground cable, and wait for 60 seconds or more. 2) Disconnect the connector (AB21) from seat belt pretensioner LH. 3) Disconnect the connector (AB5) from seat cushion airbag module LH. 4) Disconnect the connector (AB31) from curtain airbag module LH. 5) Disconnect the connector (AB19) of the side airbag module LH. 6) Disconnect the connectors (AB6, AB17, AB18) from airbag control module. 7) Connect the connector (1AD) in test harness AD AV to the connectors (AB6, AB17, AB18). 8) Connect the connector (2AD) in test harness AD AV and the connector (1AG) in test harness AG. 9) Disconnect the connector (AB23) from side airbag sensor LH, and connect the connector (2V) in test harness V to connector (AB23). 10) Measure the resistance between connector (5AG) in the test harness AG and connector (3V) in the test harness V. Connector & terminal (5AG) No. 14 — (3V) No. 2: (5AG) No. 16 — (3V) No. 1:	Is the resistance less than 10 --	Diagnostic Chart with Trouble Code > DTC B1627 SIDE AIRBAG SENSOR LH LOST COMMUNICATION	Replace the airbag rear harness along with body harness.
3.CHECK AIRBAG REAR HARNESS (BETWEEN AIRBAG CONTROL MODULE AND SIDE AIRBAG SENSOR LH) (SHORTED TO GROUND AND SHORTED BETWEEN LINES). Measure the resistance between connector (5AG) in the test harness AG and chassis ground, and the resistance between connector (5AG) terminals in the test harness AG. Connector & terminal (3V) No. 1 — Chassis ground: (3V) No. 2 — Chassis ground: (3V) No. 1 — (3V) No. 2:	Is the resistance 1 M- or more-	Diagnostic Chart with Trouble Code > DTC B1627 SIDE AIRBAG SENSOR LH LOST COMMUNICATION	Replace the airbag rear harness along with body harness.
4.CHECK AIRBAG CONTROL MODULE. 1) Connect all connectors. 2) Clear the memory. Clear Memory Mode 3) Perform the Inspection Mode. Inspection Mode 4) Read the DTC. (Current malfunction) Read Diagnostic Trouble Code (DTC)	Is DTC B1627 displayed-	Diagnostic Chart with Trouble Code > DTC B1627 SIDE AIRBAG SENSOR LH LOST COMMUNICATION	Diagnostic Chart with Trouble Code > DTC B1627 SIDE AIRBAG SENSOR LH LOST COMMUNICATION
5.CHECK SIDE AIRBAG SENSOR LH. 1) Turn the ignition switch to OFF, disconnect the battery ground cable, and wait for 60 seconds or more. 2) Replace the side airbag sensor LH by the side airbag sensor RH. Side Airbag Sensor > REMOVAL 3) Connect all connectors. 4) Clear the memory. Clear Memory Mode 5) Perform the Inspection Mode. Inspection Mode 6) Read the DTC. (Current malfunction) Read Diagnostic Trouble Code (DTC)	Is DTC B1627 displayed-	Diagnostic Chart with Trouble Code > DTC B1627 SIDE AIRBAG SENSOR LH LOST COMMUNICATION	Replace the side airbag sensor LH. Side Airbag Sensor > REMOVAL
6.CHECK CURTAIN AIRBAG SENSOR LH. 1) Turn the ignition switch to OFF, disconnect the battery ground cable, and wait for 60 seconds or more. 2) Restore the side airbag sensors LH and RH back to their original position. Side Airbag Sensor > REMOVAL 3) Replace the curtain airbag sensor LH by the curtain airbag sensor RH. Curtain Airbag Sensor > REMOVAL 4) Connect all connectors. 5) Clear the memory. Clear Memory Mode 6) Perform the Inspection Mode. Inspection Mode 7) Read the DTC. (Current malfunction) Read Diagnostic Trouble Code (DTC)	Is DTC B1627 displayed-	Diagnostic Chart with Trouble Code > DTC B1627 SIDE AIRBAG SENSOR LH LOST COMMUNICATION	Replace the curtain airbag sensor LH. Curtain Airbag Sensor > REMOVAL
7.CHECK AIRBAG CONTROL MODULE. 1) Turn the ignition switch to OFF, disconnect the battery ground cable, and wait for 60 seconds or more. 2) Restore the curtain airbag sensors RH and LH back to their original position. Curtain Airbag Sensor > REMOVAL 3) Connect all connectors. 4) Clear the memory. Clear Memory Mode 5) Perform the Inspection Mode. Inspection Mode 6) Read the DTC. (Current malfunction) Read Diagnostic Trouble Code (DTC)	Is DTC B1627 displayed-	Replace the airbag control module. Airbag Control Module > REMOVAL	Diagnostic Chart with Trouble Code > DTC B1627 SIDE AIRBAG SENSOR LH LOST COMMUNICATION
8.CHECK FOR ANY OTHER DTC ON DISPLAY. Read the DTC. (Current malfunction) Read Diagnostic Trouble Code (DTC)	Is any other DTC displayed-	Check DTC using “List of Diagnostic Trouble Code (DTC)”. List of Diagnostic Trouble Code (DTC)	Finish the diagnosis.

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Other materials:

Removal
1. SEAT HEATER MODULE - FRONT1. Remove the front seats. Front Seat > REMOVAL2. Remove the backrest cover of front seat and seat cushion cover. Front Seat > DISASSEMBLY3. Remove the seat heater module - front from the pad assembly.CAUTION:If the seat heater module is removed, replace the pad assemb ...