AIRBAG SYSTEM (DIAGNOSTICS) > Subaru Select Monitor

INSPECTION

1. COMMUNICATION FOR INITIALIZING IMPOSSIBLE

DETECTING CONDITION:

Defective harness connector

TROUBLE SYMPTOM:

Communication is impossible between the airbag control module and the Subaru Select Monitor.

WIRING DIAGRAM:

STEPCHECKYESNO

1.CHECK IGNITION SWITCH.

Is the ignition switch ON?

Turn the ignition switch to ON, and select the airbag mode using the Subaru Select Monitor.

2.CHECK BATTERY.

1) Turn the ignition switch to OFF.

2) Measure the battery voltage.

Is the voltage 11 V or more?

Charge or replace the battery.

3.CHECK BATTERY TERMINAL.

Is there poor contact at battery terminal?

Repair or tighten the battery terminal.

4.CHECK SUBARU SELECT MONITOR COMMUNICATION.

1) Turn the ignition switch to ON.

2) Using the Subaru Select Monitor, check whether communication to other systems can be executed normally.

Is the system name displayed on Subaru Select Monitor?

5.CHECK FUSE NO. 25 (IN FUSE & RELAY BOX).

Remove the fuse No. 25 and perform visual inspection.

Is the fuse No. 25 (in fuse & relay box) blown out?

Replace the fuse No. 25. If fuse No. 25 is blown out again, check the power supply circuit.

6.CHECK AIRBAG CONTROL MODULE CONNECTOR.

1) Turn the ignition switch to OFF, disconnect the battery ground cable, and wait for 20 seconds or more.

2) Confirm that the connectors of airbag control module (AB6, AB17, and AB18) are securely connected.

Is the connector of the airbag control module securely connected?

Connect the connector of the airbag control module.

7.CHECK SUBARU SELECT MONITOR COMMUNICATION.

1) Turn the ignition switch to OFF.

2) Disconnect the airbag control module connector.

3) Turn the ignition switch to ON.

4) Check whether communication to other systems can be executed normally.

Is the system name displayed on Subaru Select Monitor?

Replace the airbag control module.

8.CHECK HARNESS CONNECTOR BETWEEN EACH CONTROL MODULE AND DATA LINK CONNECTOR.

1) Turn the ignition switch to OFF.

2) Disconnect the airbag control module, VDC&H/U, ECM and TCM.

3) Measure the resistance between data link connector and chassis ground.

Connector & terminal

(B40) No. 7 — Chassis ground:

Is the resistance 1 MΩ or more?

Repair the harness and connector between each control module and data link connector. (Replace the entire harness if repair is necessary for airbag harness.)

9.CHECK OUTPUT SIGNAL TO THE AIRBAG CONTROL MODULE.

1) Turn the ignition switch to ON in the condition of step 8.

2) Measure the voltage between data link connector and chassis ground.

Connector & terminal

(B40) No. 7 (+) — Chassis ground (−):

Is the voltage less than 1 V?

Repair the harness and connector between each control module and data link connector. (Replace the entire harness if repair is necessary for airbag harness.)

10.CHECK HARNESS BETWEEN THE AIRBAG CONTROL MODULE AND DATA LINK CONNECTOR.

1) Turn the ignition switch to OFF, disconnect the battery ground cable, and wait for 20 seconds or more.

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

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

NOTE:

For model without side airbag, connect test harness AH between the connectors (AB6, AB17, AB18) and (1AG).

4) Measure the resistance between connector (4AG) in the test harness AG and the data link connector.

Connector & terminal

(4AG) No. 1 — (B40) No. 7:

Is the resistance less than 10 Ω?

Repair the harness between the airbag control module and the data link connector. Or replace the airbag main harness along with the bulkhead harness.

11.CHECK POWER SUPPLY CIRCUIT.

1) Turn the ignition switch to ON.

2) Measure the voltage between connector (2AG) in the test harness AG and chassis ground.

Connector & terminal

(2AG) No. 1 — Chassis ground:

Is the voltage 10 V or more?

Repair the harness between the airbag control module and the battery. Or replace the airbag main harness along with the bulkhead harness.

12.CHECK BETWEEN THE AIRBAG CONTROL MODULE AND CHASSIS GROUND.

1) Turn the ignition switch to OFF.

2) Measure the resistance between connector (2AG) in the test harness AG and chassis ground.

Connector & terminal

(2AG) No. 4 — Chassis ground:

(2AG) No. 3 — Chassis ground:

Is the resistance less than 10 Ω?

Repair the harness between the airbag control module and the chassis ground. Or replace the airbag main harness along with the bulkhead harness.

13.CHECK POOR CONTACT OF CONNECTOR.

Is there poor contact of the control module power supply, ground circuit and data link connector?

Repair the connector. (For airbag system connectors, do not repair but replace the entire harness.)

Replace the airbag control module only.