GF46.11-P-0001FL Steering Wheel Heater (LRH), Function
GF46.11-P-0001FL Steering wheel heater (LRH), function
- with CODE (443) Steering wheel heater
Function requirements, general
^ C. 15R On
^ Interior temperature T less than 30 degrees C
The terminal status circuit 15 is transmitted from the electronic ignition lock control unit (N73) via the interior CAN (CAN B) to the steering wheel heater control unit (N25/7).
The interior temperature value is transmitted from the AAC control and operating unit AAC (N22/7) via the interior CAN to the steering wheel heater control unit
Steering wheel heater, general
It is possible to heat the steering wheel rim using the steering wheel heater (R22/4).
The steering wheel heater function is comprised of the following partial functions:
^ Manual on/off function sequence
^ Automatic switch off function sequence
Manual on/off function sequence
Operation takes place via the steering wheel heater switch (S59/1s2) in the steering column tube module control unit (N80). The steering wheel heater is switched on and off by turning the heated steering wheel heater switch.
The request of the steering wheel heater switch is read in by the control unit steering column tube module control unit and transmitted via the chassis CAN (CAN E) to the front SAM control unit with fuse and relay module (N10/1). This transmits the information via the interior CAN to the steering wheel heater control unit.
Based on this, the steering wheel heater control unit actuates the heating element in the steering wheel heater (R22/4r1) in the steering wheel rim.
At the same time the steering wheel heater indicator lamp (S59/1e1) is actuated in the steering wheel heater switch by the steering wheel heater control unit.
The heating element temperature sensor (R22/4b1) measures the surface temperature of the steering wheel rim and transmits the value to the steering wheel electronics (N135). The latter transmits the value via the steering LIN (LIN E1) to the steering column module control unit.
The control unit steering column tube module control unit transmits the value via the chassis CAN to the front SAM control unit which passes on the information via the interior CAN to the steering wheel heater control unit.
The steering wheel heater control unit regulates the surface temperature of the steering wheel rim to T = 35 degrees C.
Automatic switch off function sequence
The timer control is realized by the steering wheel heater control unit. After expiry of t = 15 min the steering wheel heater is switched off automatically.
The timer control of the steering wheel heater can be parameterized via the Diagnose-Tester in the steering wheel heater control unit.
Other shutoff criteria:
- Shutoff in event of hardware defect
If an actuation of the steering wheel heater without any existing request or function requirement is detected, then the steering wheel heater is switched off and a fault message is stored in the fault memory.
- Shutoff in event of over temperature
If the interior temperature value T greater than 30 degrees C is reported by the AAC control and operating unit via the interior CAN to the steering wheel heater control unit, this switches off the steering wheel heater. The steering wheel heater indicator lamp remains on.
If the interior temperature drops below the cut-in temperature T less than 30 degrees C the steering wheel heater is switched on again automatically. The shutoff temperature of the steering wheel heater can be parameterized via the Diagnose-Tester in the steering wheel heater control unit.
If no plausible interior temperature value is present, the outside temperature value is used instead.
- Shutoff during starting process of the engine
The timer control continues running, the steering wheel heater indicator also remains on. No under voltage is detected during start-up.
- Cutout switch during under voltage
In the event of under voltage U less than 10.0 V the steering wheel heater control unit switches off the steering wheel heater.
If the steering wheel heater control unit switches off the function, first of all the indicator lamp steering wheel heater indicator remains on. If the on-board electrical system reaches is its normal voltage again within the following time of t = 3 min, the steering wheel heater starts again automatically.
If the shutoff takes longer than t = 3 min, the steering wheel heater indicator lamp is also switched off.
If the shutoff continues and the function is requested again, the steering wheel heater indicator lamp lights up for t = 1.5 s and then goes out again.
- Cutout switch in event of over voltage
In the event of over voltage U greater than 15.5 V the steering wheel heater control unit switches off the steering wheel heater. The timer control continues running, the steering wheel heater indicator lamp remains on.
Switching on again is only possible after a permissible voltage is applied again.
The over voltage threshold of the steering wheel heater is can be parameterized via the Diagnosis-Tester in the steering wheel heater control unit.
- Shutoff after circuit 15R OFF
If circuit 15C continues to be ON, the timer control continues running for t = 5 min. If circuit 15R is now switched on again, then the steering wheel heater is also switched on.
- Cutout switch at end of Diagnosis
Once the diagnose is ended the steering wheel heater switches off
