Checking heating elements
WARNING: This page is about a different car, the 2008 Audi S4, 2008 Audi RS 4, and 2008 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.
Special tools and equipment
- Diagnostic Operation System VAS 5051A (with Inductive Pickup (50 Amp) VAS 5051/9)
- Connector Test Set V.A.G 1594C
- Test Box V.A.G 1598A and Adapter - 16 Terminals V.A.G 1598/12
NOTE:
- All fuses OK
- Switch off ignition.
- Remove operating and display module, Climatronic Control Module J255.
- Disconnect connectors - D - and - F - from operating and display module, Climatronic Control Module J255.
- Connect test box Adapter - 16 Terminals V.A.G 1598/12 to disconnected connector - D -.
- Connect Test Box V.A.G 1598A to Adapter - 16 Terminals V.A.G 1598/12
- Measure voltage between contact "3" at connector - F - and socket "13" (Ground (GND) connection) of Test Box V.A.G 1598A.
- Specified value: approx. Battery voltage
- Measure resistance between contact "1" at connector - F - (to heater element for Drivers Seat Heating Element Z6) and socket "13" (Ground (GND) connection) of Test Box V.A.G 1598A.
- Specified value: Resistance approx. 1.5 (to 2.5) to 25 Ω (ohms)
- Measure resistance between contact "2" at connector - F - (to heater element in front passenger seat) and socket "13" (Ground (GND) connection) of Test Box V.A.G 1598A.
- Specified value: Resistance approx. 1.5 (to 2.5) to 25 Ω (ohms)
NOTE:
- Contact resistance at the various connectors may result in resistance values of up to approx. 25 Ω being measured. As soon as a voltage of 12 V is applied, this contact resistance decreases and the seat heating function is not impaired.
- On right-hand drive vehicles, the driver seat is connected to contact "2" and the front passenger seat to contact "1".
- The resistance of the seat heater elements changes with temperature (at a seat temperature of 20 °C, the resistance is approx. 1.9 Ω).
- As resistances of less than 10 Ω cannot be measured with sufficient accuracy using workshop equipment, it is not possible to establish a short circuit in the wiring or in the seat heater elements.
- If the resistance value is too high, check wiring to seat heater elements for open circuit and eliminate this. If the open circuit is in the seat, repair the seat and →
- 72 - SEAT - FRAMES
- 72 - SEAT - FRAMES for BODY INTERIOR - CABRIOLET
- Plug connectors - D - and - F - to operating and display module, Climatronic Control Module J255 (all connectors are now plugged in at operating and display module, Climatronic Control Module J255).
- Guide wire to connector - F - contact "1" through Inductive Pickup (50 Amp) VAS 5051/9.
- On Diagnostic Operation System VAS 5051A, set "Multi-meter measurement: inductive pickup (50 amp)" mode.
- Set both thumb wheels for heated seats (at operating and display module, Climatronic Control Module J255) to position "0".
NOTE:
- All connectors must be plugged in at the operating and display module, Climatronic Control Module J255.
- Start engine.
- Set thumb wheel for heated driver seat to position "6".
- Specified value: Display switches from approx. 0 A to less than 10 A
- Set thumb wheel for heated driver seat to position "0".
- Specified value: Display switches from less than 10 A to approx. 0 A
- Guide wire to connector - F - contact "2" (contact "1" on right-hand drive vehicles) through Inductive Pickup (50 Amp) VAS 5051/9.
- Set thumb wheel for heated front passenger seat to position "6".
- Specified value: Display switches from approx. 0 A to less than 10 A
- Set thumb wheel for heated front passenger seat to position "0".
- Specified value: Display switches from less than 10 A to approx. 0 A
NOTE:
- Interference on the current probe measuring leads 1 2 may cause a slight current to be displayed with the seat heating switched off.
- In the event of an open circuit or a short circuit in the connection to the seat temperature sensor, the output to the heater element is does not switch by the operating and display module, Climatronic Control Module J255.
- In the event of a short to Ground (GND) in the seat heater element or in the wiring, the operating and display module, Climatronic Control Module J255 does not switch on the heating (immediate deactivation as soon as current is too high).
- The design of the seat heater elements differs. Depending on heater element design there is thus a possibility of the two side bolsters being constantly heated, e.g. in the event of an open circuit in the seat cushion heater element (the temperature sensor is located in the seat cushion).