HEATED STEERING WHEEL SYSTEM FAIL-SAFE CHART

MALFUNCTION DETECTION (w/o Steering Wheel Vibration)

1. Operation when malfunction is detected

   Content	Operation
   When thermistor malfunction is detected	Heater off
   When overheating (175°C (347°F)) of controller is detected	Heater off
   When load short current (50 A or more) is detected	Heater off
   When undervoltage (4.5 V) is detected	Heater off
   OFF timer (30 minutes)	After preset time of timer passes, heater off
   Reverse voltage protection	Protection circuit operates

2. Malfunction detection conditions

   
   

   1. When an open or short in the steering wheel heater unit thermistor continues for 2 seconds or more.

   2. When the steering heater switch is pressed continuously for 10 seconds or more.

3. Malfunction display

   
   

   1. The LED of the steering heater switch goes off.

4. Restore condition

   
   

   1. If the normal condition is restored 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, and regardless of if the normal condition is restored and the system is operating normally, the timer will turn off the heater 30 minutes after the steering heater switch was first turned on.

MALFUNCTION DETECTION (w/ Steering Wheel Vibration)

1. Operation when malfunction is detected

   Content		Operation
   Heater failure	Overcurrent detection of drive element	Heater output off
   	Overheating detection of drive element	Heater output off
   Power failure	Low-voltage detection	Heater output off
   	Over-voltage detection	Heater output off
   Heater OFF timer	30 minutes after heated steering wheel system is turned on	Heater output off

2. Malfunction detection conditions

   
   

   1. When an open or short in the steering wheel heater unit thermistor continues for 2 seconds or more.

   2. When the steering heater switch is pressed continuously for 10 seconds or more.