Steering Wheel does not Heat Up When Heated Steering Wheel Switch is Pressed

STEERING COLUMN: HEATED STEERING WHEEL SYSTEM: Steering Wheel does not Heat Up When Heated Steering Wheel Switch is Pressed
- Steering Wheel does not Heat Up When Heated Steering Wheel Switch is Pressed

DESCRIPTION

The heater unit heats the steering wheel when the steering heater switch is operated.

HINT
* The heater unit is built into the steering wheel.
* As the steering wheel cannot be disassembled, replace the steering wheel when there is a malfunction in the heater unit.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK STEERING HEATER SWITCH (LED OPERATION)





(a) Check the illumination condition of the LED.

Result:





B -- INSPECT STEERING WHEEL ASSEMBLY (HEATER - THERMOSTAT)
A -- Continue to next step.

2. INSPECT STEERING WHEEL ASSEMBLY (THERMISTOR)

(a) Disconnect the steering wheel controller connector.

(b) Measure the resistance according to the value(s) in the table below.





Standard Resistance:





Text in Illustration





NG -- REPLACE STEERING WHEEL ASSEMBLY Removal
OK -- Continue to next step.

3. INSPECT STEERING WHEEL ASSEMBLY (HEATER - THERMOSTAT)

(a) Disconnect the steering wheel controller connector.

(b) Measure the resistance according to the value(s) in the table below.





Standard Resistance:





Text in Illustration





NG -- REPLACE STEERING WHEEL ASSEMBLY Removal
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (STEERING HEATER SWITCH - SPIRAL CABLE)

(a) Disconnect the G66 steering heater switch connector.

(b) Disconnect the G30 spiral cable connector.

(c) Measure the resistance according to the value(s) in the table below.





Standard Resistance:





Text in Illustration





(d) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





NG -- REPAIR OR REPLACE WIRE HARNESS OR CONNECTOR
OK -- Continue to next step.

5. INSPECT SPIRAL CABLE SUB-ASSEMBLY

NOTICE:
If there are any defects as mentioned below, replace the spiral cable with a new one:

Scratches, cracks, dents or chips in the connector or spiral cable.

(a) Disconnect the G30 spiral cable connector.

(b) Disconnect the heated steering wheel controller connector.

(c) Measure the resistance according to the value(s) in the table below.





Standard Resistance:





Text in Illustration





NG -- REPLACE SPIRAL CABLE SUB-ASSEMBLY Removal
OK -- Continue to next step.

6. CHECK STEERING HEATER SWITCH

(a) Disconnect the steering heater switch connector.

(b) Measure the voltage according to the value(s) in the table below.





HINT
As the circuit has a diode, perform the measurement in diode test mode and make sure that the polarity is correct.

Standard Voltage:





Text in Illustration





NG -- REPLACE STEERING HEATER SWITCH Removal

OK -- REPLACE HEATED STEERING HEATER CONTROLLER Removal