The Steering Heater Does Not Operate
- CHECK POWER SUPPLY INPUT.
- Disconnect the battery ground terminal, and wait for 60 seconds or more.
- Disconnect the connector between steering roll connector and steering heater unit.
- Connect the battery ground terminal and turn the ignition switch to ON.
- Measure the steering roll connector voltage.
Connector and terminal
(ST12) No. 4 (+) - No. 3 (-)
Is the voltage 10 - 14 V?
Yes: Go to 2.
No : Go to 5.
- CHECK STEERING HEATER SWITCH.
Check the steering heater switch. Ref. 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. Ref. to POWER ASSISTED SYSTEM (POWER STEERING)>STEERING WHEEL>DISASSEMBLY .
- CHECK STEERING HEATER UNIT.
Check the steering heater unit. Ref. to POWER ASSISTED SYSTEM (POWER STEERING)>STEERING HEATER SYSTEM>ELECTRICAL SPECIFICATION>STEERING HEATER UNIT .
Is the steering heater unit OK?
Yes: Go to 4.
No : Replace the steering heater unit. Ref. to POWER ASSISTED SYSTEM (POWER STEERING)>STEERING WHEEL>DISASSEMBLY .
- CHECK STEERING WHEEL.
Check the steering wheel. Ref. to POWER ASSISTED SYSTEM (POWER STEERING)>STEERING WHEEL>INSPECTION>STEERING WHEEL HEATER .
Is the steering wheel OK?
Yes: It is possible that temporary poor contact occurs. Restore the parts and check it again.
No : Replace the steering wheel. Ref. to POWER ASSISTED SYSTEM (POWER STEERING)>STEERING WHEEL .
- CHECK FUSE.
- Turn the ignition switch to OFF.
- Check the fuse No. 33 in the fuse & relay box.
Is the fuse OK?
Yes: Go to 6.
No : Replace the fuse.
- CHECK RELAY.
Check the steering heater relay. Ref. to POWER ASSISTED SYSTEM (POWER STEERING)>RELAY AND FUSE .
Is the steering heater relay OK?
Yes: Go to 7.
No : Replace the steering heater relay.
- CHECK BATTERY VOLTAGE.
Measure the battery voltage.
Is the battery OK?
Yes: Go to 8.
No : Check the battery. Ref. to STARTING/CHARGING SYSTEMS (H4DOTC)>BATTERY>INSPECTION .
- CHECK ROLL CONNECTOR (HEATER).
Measure the resistance between steering roll connectors (heater part). Ref. to COMMUNICATION SYSTEM>HORN SWITCH>INSPECTION>CHECK STEERING ROLL CONNECTOR .
Is the steering roll connector OK?
Yes: It is possible that temporary poor contact occurs. Restore the parts and check it again.
No : Replace the steering roll connector. Ref. to AIRBAG SYSTEM>ROLL CONNECTOR .