374113 - O21 DRIVER'S SEAT HEATING IS NOT WORKING

the driver's seat heater pad and potentiometer are connected to the Driving Position Node.The seat heater pad consists of two elements, fitted in the seat and the backrest, controlled in parallel by the Driving Position Node.The heater pad in the seat has an NTC sensor for controlling the temperature.
STEPOPERATIONS TO BE CARRIED OUTTEST RESULTS
1CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Connect the Examiner diagnostic equipment to the diagnostic connect and check the following at the Driving Position NodeIn errors ambient

  • that there are no faults
In parameters ambient

  • the plausibility of the heater pad potentiometer parameter
In active diagnosis ambient

  • the operation of the heater pad
Move on to Step 1. presence of faults1. continue following the instructions for the diagnostic equipment.
2. heater pad potentiometer parameter not plausibleMove on to Step
3. heater pad not workingMove on to Step
2COMPONENT CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Remove the control panel and check:

  • the operation of the temperature selector
  • the electrical connection between the Driving Position Node and the potentiometer (Wiring Diagram ) E3075 HEATED SEATS
Move on to Step 1. Temperature selector faulty1. Replace the temperature selector
2. Electrical equipment faulty2. Restore the electrical connection (Wiring Diagram ) E3075 HEATED SEATS
3ELECTRICAL SYSTEM CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Remove the seat and check the electrical connection between:

  • Driving Position Node and heater pad in seat
  • Driving Position Node and sensor for heater pad in seat
  • Driving Position Node and backrest heater pad
  • Heater pads and earth (Wiring Diagram ) E3075 HEATED SEATS
Move on to Step Electrical equipment faultyRestore the electrical connection (Wiring Diagram ) E3075 HEATED SEATS
4COMPONENT CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check

  • the resistance of the heater pads (about 5.5 ohm at 20 degrees)
  • the resistance of the heater pad sensor (about 1 kohm at 20 degrees) (Wiring Diagram ) E3075 HEATED SEATS
Move on to Step 1. Heater pads broken1. Replace the heater pads
2. Sensor broken2. Replace the seat heater pad.
5CHECK ON CORRECT OPERATIONALL OKPROBLEMS ENCOUNTEREDACTION
Check that the fault is no longer presentFault persistsReplace the Driving Position Node