Front Seat Heating, Checking

The Components Involved with the Seat Heating Actuation:

The Heater Control Module -J65- (vehicles without A/C system), the A/C Control Module -J301- (vehicles with manually regulated A/C system), or the Climatronic Control Module -J255- (vehicles with Automatic climate control) control head sends the request to activate the heated seats via the Data Bus. The Vehicle Electrical System Control Module -J519- then directly activates the heating elements in the seats. Use the Vehicle Diagnostic Tester in the"Guided Fault Finding"  function and Wiring diagrams, Troubleshooting & Component locations.

Check the seat heating function and actuation using the Vehicle Diagnostic Tester in the"Guided Fault Finding"  function for the Vehicle Electrical System Control Module -J519-.

Procedure 

Courtesy of AUDI OF AMERICA, LLC

The seat heating is set via the buttons -1 and 3- on the Heater Control Module -J65- /A/C Control Module -J301- -A- or Climatronic Control Module -J255- -B- control head.

• When the seat heating is switched on, the function indicator lamps in the buttons -1 and 3- illuminate. Refer to the Vehicle Owner's Manual.
• If it is not possible to switch on the heated seats due to a switch off condition detected by the Vehicle Electrical System Control Module -J519-, the Vehicle Electrical System Control Module -J519- sends the corresponding information back to the control head via the Data Bus. The function indicator lamps in the buttons -1 and 3- do not illuminate or go out.
• The seat heating is adjusted on the control head (Heater Control Module -J65-, A/C Control Module -J301- or Climatronic Control Module -J255-). The specified temperatures for the different seat heating settings are stored in the Vehicle Electrical System Control Module -J519-. Depending on the Vehicle Electrical System Control Module -J519- version, the specified temperature for the seat heating can be different with the same setting on the control head. Use the Vehicle Diagnostic Tester in the"Guided Fault Finding"  function and Wiring diagrams, Troubleshooting & Component locations.
• The adjusted setting for the driver seat heating can be stored in a key-dependent manner in the control head (Heater Control Module -J65-, A/C Control Module -J301- or Climatronic Control Module -J255-). The settings made prior to the ignition being switched off are applied during the next driving cycle. Refer to the Owner's Manual.
• Depending on the vehicle and the control head (Heater Control Module -J65-, A/C Control Module -J301- or Climatronic Control Module -J255-), the adjusted setting for the seat heating automatically reduces after a certain amount of time (for example, after 10 minutes). Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function and the Owner's Manual. 
• For vehicles with the Start/Stop System, the heated seats can be switched off to protect the Battery -A- when the stop function is active. The setting for seat heating activation remains stored however in the control head (Heater Control Module -J65-, A/C Control Module -J301- or Climatronic Control Module -J255-). The heated seats are switched on again as soon as the engine is restarted via the start function. Use the Vehicle Diagnostic Tester in the"Guided Fault Finding"  function (for the Vehicle Electrical System Control Module -J519-).
• On vehicles without the passenger occupant detection system for the front passenger seat, the seat heating is currently not switched off automatically by the control head (Heater Control Module -J65-, A/C Control Module -J301- or Climatronic Control Module -J255-) if there is an unoccupied seat while driving. If the ignition is turned off and not turned on again within about 10 minutes, the setting for the seat heating activation is erased. Refer to the Owner's Manual.
• If, for example, the Vehicle Electrical System Control Module -J519- voltage measured at terminal "30" falls below a value stored in the Vehicle Electrical System Control Module -J519-, the seat heating is output is reduced or switched off completely to reduce the load on the Generator -C-. Use the Vehicle Diagnostic Tester in the"Guided Fault Finding"  function for the Vehicle Electrical System Control Module -J519-.
• If there is a condition that prevents the driver or passenger seat heating from switching on (for example, there is an open circuit in the voltage supply to the particular control module, etc.), this will be stored as a fault in the Vehicle Electrical System Control Module -J519-. In this vehicle, information stating that the event memory in the relevant control module needs to be read out may not be sent via the Data Bus to the control head (Heater Control Module -J65-, A/C Control Module -J301- or Climatronic Control Module -J255-). Use the Vehicle Diagnostic Tester in the"Guided Fault Finding"  function. In the event of a complaint regarding seat heating, first check the event memory of the control modules activating the seat heating, for example the Vehicle Electrical System Control Module -J519-.
• Depending on the version and equipment of the vehicle, the various information regarding seat heating activation (the setting transmitted by the Heater Control Module -J65-, A/C Control Module -J301- or Climatronic Control Module -J255- control head, the target and actual seat temperature, etc.) is displayed in different measured value blocks in various control modules. Use the Vehicle Diagnostic Tester in the"Guided Fault Finding"  function.
• In the"Guided Fault Finding"  "Read measured values" function for the control head (Heater Control Module -J65-, A/C Control Module -J301- or Climatronic Control Module -J255-) the selected setting for the seat heating is displayed. The seat heating activation, the actual and target seat temperature, the actual current supplied to the seat heating, etc. are displayed in the "Read measured values" function of the Vehicle Electrical System Control Module -J519-, depending on the vehicle version and equipment. Use the Vehicle Diagnostic Tester in the"Guided Fault Finding"  function.
• The function test of heated seat activation is described in the"Guided Fault Finding"  for the Vehicle Electrical System Control Module -J519- on the Vehicle Diagnostic Tester.