DTC B0004[1B] Driver Knee Airbag Circuit High Resistance (Air Bag (Driver/Passenger/Side/Roof/Knee/Far Side))

1. SRS system check

Refer to "58.SRS Control 8A.Troubleshooting(Air Bag (Driver/Passenger/Side/Roof/Knee/Far Side)) diagnostic system check-SRS controls".

2. Driver knee airbag circuit resistance check

1) Observe the Driver Knee Airbag Loop Resistance parameter on the scan tool. Is the Driver Knee Airbag Loop Resistance parameter more than or equal to the specified value?

Value: 7 Ω

Yes

=>Go to Connection check for driver knee airbag harness connector.

Go to Intermittent conditions of SRS control.

Refer to "209.Restraints 22D.Symptom Intermittent conditions of SRS control".

3. Connection check for driver knee airbag harness connector

4. SRS coil harness connector connection verification

1) Turn OFF the ignition switch for 15 seconds or more.

2) Verify that the driver knee airbag harness connector (B81) is securely connected. Is the driver knee airbag harness connector (B81) securely connected?

Refer to "LHD SRS airbag (Driver/Passenger/Side/Curtain/Knee)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD SRS airbag (Driver/Passenger/Side/Curtain/Knee)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD SRS airbag (Driver/Passenger/Side/Curtain/Knee/Far Side)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to Driver knee airbag harness connector inspection.

Securely connect the driver knee airbag harness connector (B81).

=>Go to Repair verification.

5. Driver knee airbag harness connector inspection

6. SRS coil harness connector inspection

1) Disconnect the driver knee airbag harness connector (B81).

2) Inspect the driver knee airbag harness connector terminals (pins 1 and 2 of B81) for bending, dirt, etc. Is the result normal?

Refer to "LHD SRS airbag (Driver/Passenger/Side/Curtain/Knee)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD SRS airbag (Driver/Passenger/Side/Curtain/Knee)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD SRS airbag (Driver/Passenger/Side/Curtain/Knee/Far Side)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to Current DTC check.

Repair the connections as necessary.

=>Go to Repair verification.

7. Current DTC check

1) Connect the driver knee airbag harness connector (B81).

Refer to "LHD SRS airbag (Driver/Passenger/Side/Curtain/Knee)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD SRS airbag (Driver/Passenger/Side/Curtain/Knee)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD SRS airbag (Driver/Passenger/Side/Curtain/Knee/Far Side)" in the ETM (wiring diagram). (Open using the ETM viewer.).

2) Turn ON the ignition switch.

3) Observe the DTC information with a scan tool for DTC B0004[1B] being set as a current failure. Is a DTC set?

Yes

=>Go to Driver knee airbag circuit check.

=>Go to Repair verification.

8. Driver knee airbag circuit check

1) Turn OFF the ignition switch for 15 seconds or more.

2) Disconnect the driver knee airbag harness connector (B81).

3) Connect the SRS alternative load and the appropriate adapter from the adapter harness kit to the SRS control unit side of the driver knee airbag harness connector (B81).

Refer to "LHD SRS airbag (Driver/Passenger/Side/Curtain/Knee)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD SRS airbag (Driver/Passenger/Side/Curtain/Knee)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD SRS airbag (Driver/Passenger/Side/Curtain/Knee/Far Side)" in the ETM (wiring diagram). (Open using the ETM viewer.).

SST: 5-8840-2857-0 - adapter harness kit

SST: 5-8840-2856-0 - SRS alternative load

4) Turn ON the ignition switch.

5) Observe the DTC information with a scan tool for DTC B0004[1B] being set as a current failure. Is a DTC set?

Yes

=>Go to Inspection for open circuit in driver knee airbag deployment current output (High) circuit.

Replace the driver knee airbag.

Refer to "8.Restraints 8B.Airbag Systems knee air bag removal".

Refer to "8.Restraints 8B.Airbag Systems knee air bag installation".

=>Go to Repair verification.

9. Inspection for open circuit in driver knee airbag deployment current output (High) circuit

1) Turn OFF the ignition switch for 15 seconds or more.

2) Inspect the driver knee airbag deployment current output (High) circuit between the SRS control unit (pin 16 of B9) and the driver knee airbag (pin 2 of B81) for an open circuit or high resistance. Is the result normal?

Refer to "LHD SRS airbag (Driver/Passenger/Side/Curtain/Knee)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD SRS airbag (Driver/Passenger/Side/Curtain/Knee)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD SRS airbag (Driver/Passenger/Side/Curtain/Knee/Far Side)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to Inspection for open circuit in driver knee airbag deployment current output (Low) circuit.

Repair the circuit as necessary.

=>Go to Repair verification.

10. Inspection for open circuit in driver knee airbag deployment current output (Low) circuit

1) Inspect the driver knee airbag deployment current output (Low) circuit between the SRS control unit (pin 17 of B9) and the driver knee airbag (pin 1 of B81) for an open circuit or high resistance. Is the result normal?

Refer to "LHD SRS airbag (Driver/Passenger/Side/Curtain/Knee)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD SRS airbag (Driver/Passenger/Side/Curtain/Knee)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD SRS airbag (Driver/Passenger/Side/Curtain/Knee/Far Side)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to SRS control unit harness connector inspection.

Repair the circuit as necessary.

=>Go to Repair verification.

11. SRS control unit harness connector inspection

1) Inspect for poor connections at the SRS control unit harness connector (pins 16 and 17 of B9). Is the result normal?

Refer to "LHD SRS airbag (Driver/Passenger/Side/Curtain/Knee)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD SRS airbag (Driver/Passenger/Side/Curtain/Knee)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD SRS airbag (Driver/Passenger/Side/Curtain/Knee/Far Side)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to SRS control unit replacement.

Repair the connections as necessary.

=>Go to Repair verification.

12. SRS coil check

13. SRS control unit replacement

Note

Perform the VIN programming and ECU lock after replacing the SRS control unit.

Refer to "8.Restraints 8Z.Seat Belt and SRS Airbag Electrical Control SRS control unit removal".

Refer to "8.Restraints 8Z.Seat Belt and SRS Airbag Electrical Control SRS control unit installation".

Refer to "8.Restraints 8Z.Seat Belt and SRS Airbag Electrical Control SRS control unit setting".

Procedure completion

=>Go to Repair verification.

14. Repair verification

1) Reconnect all of the disconnected harness connectors.

2) Clear the DTC with a scan tool.

3) Turn OFF the ignition switch for 15 seconds or more.

4) Turn ON the ignition switch.

5) Observe the DTC information with a scan tool.