Subaru Legacy BN/BS (2015-2019) Service Manual: Dtc b1801 open in driver's airbag

Subaru Legacy BN/BS (2015-2019) Service Manual / Airbag system (diagnostics) / Diagnostic chart with trouble code / Dtc b1801 open in driver's airbag

DIAGNOSIS START CONDITION:

Ignition voltage is 10 V to 16 V.

DTC DETECTING CONDITION:

Open circuit failure (open circuit in main harness, open circuit in roll connector, open circuit in driver’s airbag, open circuit in airbag CM internal circuit, connectors connection failure)

CAUTION:

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

NOTE:

Prior to starting work, prepare two AIRBAG RESISTORs (98299PA040).

WIRING DIAGRAM:

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 driver’s airbag module.	Is there poor contact-	Replace the airbag harness.	Diagnostic Chart with Trouble Code > DTC B1801 OPEN IN DRIVER'S AIRBAG
2.CHECK DRIVER’S AIRBAG MODULE. 1) Turn the ignition switch to OFF, disconnect the battery ground cable, and wait for 60 seconds or more. 2) Remove the driver’s airbag module. 3) Connect the connector (1N) in the test harness N to the connector (AB38). 4) Connect the airbag resistor to the connector (2N) of test harness N. 5) Connect the connector (1Q) in the test harness Q to connector (AB37). 6) Connect the airbag resistor to the connector (2Q) in the test harness Q. 7) 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 driver’s airbag module. Driver’s Airbag Module	Diagnostic Chart with Trouble Code > DTC B1801 OPEN IN DRIVER'S AIRBAG
3.CHECK ROLL CONNECTOR AND AIRBAG MAIN HARNESS (DRIVER’S AIRBAG HARNESS) (SHORTED BETWEEN LINES). 1) Turn the ignition switch to OFF, disconnect the battery ground cable, and wait for 60 seconds or more. 2) Remove the console front panel and disconnect the connector (AB9). 3) Disconnect the airbag resistor from the connector (2N) in test harness N. 4) Disconnect the airbag resistor from the connector (2Q) of test harness Q. 5) Disconnect the connectors (AB6, AB17, AB18) from airbag control module. 6) Measure the resistance between connector (2Q) terminals in test harness Q. Connector & terminal (2Q) No. 1 — (2Q) No. 2:	Is the resistance less than 10 --	Diagnostic Chart with Trouble Code > DTC B1801 OPEN IN DRIVER'S AIRBAG	Diagnostic Chart with Trouble Code > DTC B1801 OPEN IN DRIVER'S AIRBAG
4.CHECK ROLL CONNECTOR (SHORTED BETWEEN LINES). 1) Remove the instrument panel lower cover and column cover, and disconnect the connector (AB7) from (AB2). 2) Measure the resistance between connector (2Q) terminals in test harness Q. Connector & terminal (2Q) No. 1 — (2Q) No. 2:	Is the resistance less than 10 --	Replace the airbag main harness along with body harness.	Replace the roll connector. Roll Connector
5.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 B1801 displayed-	Replace the airbag control module. Airbag Control Module	Diagnostic Chart with Trouble Code > DTC B1801 OPEN IN DRIVER'S AIRBAG
6.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.

Dtc b1802 short in driver's airbag (to ground)

DIAGNOSIS START CONDITION:Ignition voltage is 10 V to 16 V.DTC DETECTING CONDITION:GND short circuit failure (shorted to ground in main harness, shorted to ground in roll connector, shorted to ground ...

Dtc b1800 short in driver's airbag

DIAGNOSIS START CONDITION:Ignition voltage is 10 V to 16 V.DTC DETECTING CONDITION:Shorted between +/− lines (shorted between main harness lines, shorted between roll connector lines, shorted be ...

Other materials:

16
Detected when ignition switch is turned to OFF or malfunction related to the ignition switch occurs.TROUBLE SYMPTOM:Cruise control cannot be set.WIRING DIAGRAM:Cruise control system Cruise Control System > WIRING DIAGRAMSTEPCHECKYESNO1.CHECK IGNITION SWITCH CIRCUIT.1) Turn the ignition switch to OF ...