A3 Quattro L4-2.0L Turbo (CBFA) (2009)
Seat Heater: Testing and Inspection
Heating
Seat Heater, Activation
Special tools, testers and auxiliary items required
‹› Test Box 105 Pin (V.A.G 1598/42-1) and Test Adapter (V.A.G 1598/47)
‹› Vehicle Diagnostic, Testing and Information System ( VAS 5051 A) with Multimeter Leads (VAS 5051/7 )
‹› The Heater Control Module (J65) provides a voltage via the Heated Driver Seat Adjuster (E94) and Heated Front Passenger Seat Adjuster (E95)
(a potentiometer is operated via the respective knurled wheel - C -).
‹› The voltage supplied by Heater Control Module (J65 ) - A - with seat heater switched on is dependent on the knurled wheel position and on the
vehicle voltage supply, it is in the range of less than 0.5 volts in position "0" to approximately 10 volts in position "5" (measured to Ground
-GND- e.g. at connector - B - terminal "20") with engine running. The voltage is transferred via connector - B - (from terminal "11" to Driver Seat
Heater Control Module (J726) and from terminal "15" to Front Passenger Seat Heater Control Module (J727)) Wiring diagrams, Troubleshooting
& Component location.
‹› Resistance of seat heater potentiometer is dependent on the knurled wheel position, it cannot be measured using workshop equipment.
‹› Check function of seat heater and repair. Refer to Vehicle Diagnosis, Testing and Information System VAS 5051 under "Guided Fault Finding.
‹› Beginning with MY 2009 and as a running change, seat heating control modules are being installed that control the seat heating temperature at a
lower characteristic curve.
‹› Beginning with MY 2010, a Start/Stop System is offered as an option on certain engines. If the vehicle has a Start/Stop System, seat heating is
switched off when the stop function is active (by the Vehicle Electrical System Control Module (J519) to protect the Battery (A)). After the engine