The Steering Heater Does Not Operate

CHECK POWER SUPPLY INPUT .
1. Disconnect the ground terminal from battery sensor and wait for 60 seconds or more.
2. Disconnect the connector between steering roll connector and steering heater unit.
3. Connect the ground terminal to the battery sensor and turn the ignition switch to ON.
4. Measure the steering roll connector voltage.
  Connector & terminal
  
  (Sg11) No. 4 (+) - No. 3 (-)
Is the voltage 10 - 14 V?

Yes : Go to 2.

No : Go to 8.
CHECK STEERING HEATER SWITCH .
Check the steering heater switch. Refer to POWER ASSISTED SYSTEM (POWER STEERING)>Steering Wheel>INSPECTION>STEERING HEATER SWITCH .

Is the steering heater switch OK?

Yes : Go to 3.

No : Replace the steering heater switch. Refer to POWER ASSISTED SYSTEM (POWER STEERING)>Steering Wheel>DISASSEMBLY .
CHECK STEERING HEATER UNIT .
Check the steering heater unit. Refer to POWER ASSISTED SYSTEM (POWER STEERING)>ELECTRICAL SPECIFICATION>STEERING HEATER UNIT .

Is the steering heater unit OK?

Yes : Go to 4.

No : Replace the steering heater unit. Refer to POWER ASSISTED SYSTEM (POWER STEERING)>Steering Wheel>DISASSEMBLY .
CHECK STEERING WHEEL .
Check the steering wheel. Refer to POWER ASSISTED SYSTEM (POWER STEERING)>Steering Wheel>INSPECTION>STEERING WHEEL HEATER

Is the steering wheel OK?

Yes : Go to 5.

No : Replace the steering wheel. Refer to POWER ASSISTED SYSTEM (POWER STEERING)>Steering Wheel .
CHECK HARNESS .
Check the harness between steering roll connector and steering heater unit.

Connector & terminal

(Sg1) No. 3 - (Sg23) No. 1:

(Sg1) No. 4 - (Sg23) No. 4:

Is harness normal?

Yes : Go to 6.

No : Repair or replace the harness.
CHECK HARNESS .
Check the harness between steering heater switch and steering roll connector.

Connector & terminal

(Sg33) No. 1 - (Sg1) No. 4:

Is harness normal?

Yes : Go to 7.

No : Repair or replace the harness.
CHECK HARNESS .
Check the harness between steering heater switch and steering heater unit.

Connector & terminal

(Sg33) No. 4 - (Sg23) No. 2:

(Sg33) No. 2 - (Sg23) No. 3:

Is harness normal?

Yes : Go to 8.

No : Repair or replace the harness.

CHECK ROLL CONNECTOR (HEATER) .

Turn the ignition switch to OFF.
Disconnect the ground terminal from the battery sensor, and wait for at least 60 seconds before starting work. Refer to Repair Contents>Note>Battery .
Remove the steering roll connector. Refer to Airbag System>Roll Connector>Removal .

Measure the resistance between connectors.

Preparation tool:

Circuit tester

Courtesy of SUBARU OF AMERICA, INC.

Terminal No.	Inspection conditions	Standard
G3 - H2	Always	Less than 1 Ω
G4 - H4	Always	Less than 1 Ω

Is the measured value within the standard value?

Yes : Go to 9.

No : Replace the steering roll connector. Refer to Airbag System>Roll Connector .

CHECK HARNESS .
Measure the resistance between connector of steering roll connector and body ground and between relay holder and body ground.

Connector & terminal

(i96) No. 2 - Chassis ground:

(i12) No. 2 - Chassis ground:

Is the resistance less than 10 Ω?

Yes : Go to 10.

No : Repair or replace the harness.
CHECK HARNESS .
Check the harness between relay holder and steering roll connector.

Connector & terminal

(i12) No. 4 - (i96) No. 4:

Is harness normal?

Yes : Go to 11.

No : Repair or replace the harness.
CHECK FUSE .
1. Turn the ignition switch to OFF.
2. Check the fuse No. 35 in the fuse & relay box.
Is the fuse OK?

Yes : Go to 12.

No : Replace the fuse.
CHECK RELAY .
Check the steering heater relay. Refer to POWER ASSISTED SYSTEM (POWER STEERING)>Relay and Fuse .

Is the steering heater relay OK?

Yes : Go to 13.

No : Replace the steering heater relay.
CHECK BATTERY VOLTAGE .
Measure the battery voltage.

Is the battery OK?

Yes : It is possible that temporary poor contact occurs. Restore the parts and check it again.

No : Check the battery. Refer to Starting/Charging Systems (H4DO)>Battery>Inspection .