Subaru Crosstrek Service Manual: Dtc b1908 short in front p/t lh (to +b)

Diagnosis start condition:

Ignition voltage is 10 V to 16 V.

DTC detecting condition:

• Seat belt pretensioner (LH) circuit is shorted to power supply.

• Pretensioner (LH) is faulty.

• Pretensioner harness (LH) is faulty.

• Airbag control module is faulty.

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

1.CHECK POOR CONTACT OF CONNECTORS.

Check for poor contact of the connectors between the airbag control module and the seat belt pretensioner LH.

Is there poor contact?

Replace the airbag rear harness along with body harness.

Diagnostic Chart with Trouble Code > DTC B1908 SHORT IN FRONT P/T LH (TO +B)">Go to Step 2.

2.CHECK SEAT BELT PRETENSIONER.

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) Connect the connector (1N) in the test harness N to the connector (AB21).

4) Connect the airbag resistor to the connector (2N) of test harness N.

5) Connect the battery ground terminal and turn the ignition switch to ON.

Does the airbag warning light illuminate for six seconds and go off?

Replace the seat belt pretensioner (LH). Front Seat Belt">

Diagnostic Chart with Trouble Code > DTC B1908 SHORT IN FRONT P/T LH (TO +B)">Go to Step 3.

3.CHECK AIRBAG REAR HARNESS (PRETENSIONER HARNESS LH).

1) Turn the ignition switch to OFF, disconnect the battery ground cable, and wait for 60 seconds or more.

2) Disconnect the airbag resistor from the connector (2N) of test harness N.

3) Disconnect connector (AB19) from side airbag module (LH).

4) Disconnect the connector (AB31) from curtain airbag module (LH).

5) Disconnect the connectors (AB6, AB17, AB18) from airbag control module.

6) Connect the connector (1AG) in the test harness AG to the connectors (AB6, AB17, AB18).

7) Connect the battery ground terminal and turn the ignition switch to ON.

8) Measure the voltage between connector (3AG) in the test harness AG and chassis ground.

Connector & terminal

(3AG) No. 10 (+) — Chassis ground (−):

(3AG) No. 12 (+) — Chassis ground (−):

Is the voltage less than 1 V?

Diagnostic Chart with Trouble Code > DTC B1908 SHORT IN FRONT P/T LH (TO +B)">Go to Step 4.

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 B1908 displayed?

Replace the airbag control module. Airbag Control Module">

Diagnostic Chart with Trouble Code > DTC B1908 SHORT IN FRONT P/T LH (TO +B)">Go to Step 5.

5.CHECK FOR ANY OTHER DTC ON DISPLAY.

Is any other DTC displayed?

Check DTC using “List of Diagnostic Trouble Code (DTC)”. List of Diagnostic Trouble Code (DTC)">

Finish the diagnosis.

Dtc b19f0 short in front p/t 2 rh

Dtc b1905 short in front p/t lh

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