FAIL-SAFE CHART [01/2012 - ]
- MALFUNCTION DETECTION Operation when malfunction is detected Content Operation When thermistor trouble is detected Heater turns off When overheating (150°C (302°F)) of controller is detected Heater turns off When overvoltage (60 V) is detected Heater turns off When undervoltage (6 V) is detected Heater turns off After preset time of timer passes (30 min.) Heater turns off Malfunction detection conditions An open or short in the steering wheel thermistor continues for 2 seconds or more. The steering heater switch is pressed continuously for 10 seconds or more. Malfunction display The LED of the steering heater switch blinks at 0.3 second intervals. Restore condition If the system returns to normal for 2 seconds or more, the previous operation before the malfunction occurred continues. However, regardless of if a malfunction is detected and the malfunction operation is occurring, or if the system returns to normal, the timer will turn off the heater 30 minutes after the switch was first turned on.
PROCEDURE
- CHECK COMBINATION SWITCH ASSEMBLY (LED OPERATION) Check the illumination condition of the LED. Result LED Condition Proceed to Blinks Engine switch on (IG) Combination switch is pushed and held continuously for 10 seconds or more A Illuminates Engine switch on (IG) Combination switch is pushed B Does not blink or illuminate Engine switch on (IG) Combination switch is pushed B B --> See step 3 A: Go to next step
- INSPECT STEERING WHEEL ASSEMBLY (THERMISTOR) Disconnect the steering wheel controller connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1 (TH2) - 3 (TH1) 25°C (77°F) 9.7 to 10.3 kohms TEXT IN ILLUSTRATION *a Front view of wire harness connector (to Heated Steering Wheel Controller) NG --> See step 7 OK: Go to next step
- INSPECT STEERING WHEEL ASSEMBLY (HEATER.THERMOSTAT) Disconnect the steering wheel controller connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 2 (SH2) - 4 (SH1) 20°C (68°F) 1.88 to 2.26 ohms TEXT IN ILLUSTRATION *a Front view of wire harness connector (to Heated Steering Wheel Controller) NG --> See step 7 OK: Go to next step
- CHECK HARNESS AND CONNECTOR (COMBINATION SWITCH - SPIRAL CABLE) Disconnect the E102 combination switch connector. Disconnect the E103 spiral cable connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E102-1 (+) - E103-1 (BTM) Always Below 1 ohms E102-11 (IN) - E103-3 (ETM) Always Below 1 ohms E103-2 (EHT) - Body ground Always Below 1 ohms TEXT IN ILLUSTRATION *a Front view of wire harness connector (to Combination switch) *b Front view of wire harness connector (to Spiral Cable) Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition E103-4 (BHT) - Body ground Engine switch on (IG) 11 to 14 V NG --> REPAIR OR REPLACE WIRE HARNESS OR CONNECTOR OK: Go to next step
- INSPECT SPIRAL CABLE SUB-ASSEMBLY NOTE: 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. Disconnect the E103 spiral cable connector. Disconnect the heated steering wheel controller connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1 (CCU) - E103-1 (BTM) Always Below 1 ohms 2 (CCV) - E103-3 (ETM) Always Below 1 ohms 3 (CCX) - E103-2 (EHT) Always Below 1 ohms 4 (CCW) - E103-4 (BHT) Always Below 1 ohms TEXT IN ILLUSTRATION *a Component without harness connected (Spiral Cable) *b Front view of harness connector (to Heated Steering Wheel Controller) NG --> See step 9 OK: Go to next step
- CHECK COMBINATION SWITCH ASSEMBLY Disconnect the combination switch connector. 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 Tester Connection Positive (+) tester probe - Negative (-) tester probe Switch Condition Specified Condition E102-9 (IG) - E102-11 (IN) Combination switch is pushed Below 1.25 V TEXT IN ILLUSTRATION *a Component without harness connected (to Combination switch) NG --> See step 8 OK --> See step 10
- REPLACE HEATED STEERING WHEEL CONTROLLER. Refer to «REMOVAL [01/2012 - ] - Step 6»(ref-603959-S21030337402014031100000)
- REPLACE COMBINATION SWITCH ASSEMBLY. Refer to «REMOVAL [01/2012 - ]»(ref-603959-S26327421542014031100000)
- REPLACE SPIRAL CABLE SUB-ASSEMBLY. Refer to «REMOVAL [01/2012 - ]»(ref-603953-S03456294402014031100000)
- REPLACE HEATED STEERING WHEEL CONTROLLER. Refer to «REMOVAL [01/2012 - ] - Step 6»(ref-603959-S21030337402014031100000)