Audi Q7: Seat Heating
Front Seat Heating
Note
Depending on vehicle equipment, there are different versions of the A/C system for the Audi Q7. Make sure to use the correct version and pay attention to the allocation of different components. Refer to → Chapter "A/C System Versions" and Parts Catalog.
Components that are involved in the activation of the front seat heating (seat ventilation)
The Front A/C Display Control Head -E87- (version -A- with a "Low" and "Mid" A/C system, or version -B- with a "Mix" and "High" A/C system) sends the request to switch on the seat heating (and seat ventilation) for the front seats to the respective control module (the affected control module depends on the vehicle version and the vehicle equipment for the respective control module) via the data bus. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" function and refer to → Wiring diagrams, Troubleshooting & Component locations.
- For vehicles without seat ventilation, the Vehicle Electrical System Control Module -J519- activates the seat heating for the driver and front passenger side, depending on the request from the Front A/C Display Control Head -E87-. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" function. Refer to → Wiring diagrams, Troubleshooting & Component locations (for the respective vehicle system).
- A Start/Stop System is available for certain engines for this vehicle. For vehicles with a Start/Stop System, the seat heating can be switched off for the time in which the Stop function is active (to protect the Battery -A-). The setting for activating the seat heating remains stored however in the Front A/C Display Control Head -E87-. After the engine was restarted using the Start function, the seat heating is switched on again. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
- The set driver seat heating stage can be stored in a key-dependent manner. The settings made prior to the ignition being switched off are applied during the next driving cycle. Refer to Operating Instructions.
- For vehicles without the passenger occupant detection system for the front passenger and rear seats, there is currently no automatic shut-off for the seat heating when there is an unoccupied seat while driving. If the ignition is turned off and not turned on again within approximately 10 minutes, the activation setting for the seat heating is erased. Refer to the Owner's Manual.
- Depending on the vehicle, the seat heating setting automatically reduces after a certain amount of time (for example, after 10 minutes). Refer to the Owner's Manual.
Note
- Seat heating activation can differ, depending on the vehicle version. Refer to → Wiring diagrams, Troubleshooting & Component locations.
- Depending on the vehicle version and equipment, the various information regarding the seat heating activation (setting transmitted by the Front A/C Display Control Head -E87-, the specified and actual temperature of the seat, etc.) is displayed differently in various measured values in different control modules. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
- If there is a condition in which the driver or front passenger seat heating cannot be switched on (for example, short circuit in the connection to a seat heating element, interruption in the power supply to the respective control module, etc.), it is stored as a malfunction in the Vehicle Electrical System Control Module -J519- (depending on the vehicle version and equipment level). For this vehicle, information stating that the DTC memory in the respective control module must be read out may not be sent via the data bus to the Front A/C Display Control Head -E87-. Refer to 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.
- The function test for the seat heating activation is described in Guided Fault Finding for the respective control module (for example, in the Vehicle Electrical System Control Module -J519-, depending on the vehicle version and equipment). Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
- If, for example, the voltage at terminal "30" measured at the Vehicle Electrical System Control Module -J519- falls below a value stored in the Vehicle Electrical System Control Module -J519-, the seat heating output is reduced or switched off completely in order to reduce the load on the Generator -C-. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
- In the "Read measured values" function of Guided Fault Finding, the Front A/C Display Control Head -E87- indicates what level the seat heating is set at. The seat heating activation, the actual and specified seat temperature, the actual current supplied to the seat heating, etc. are displayed in the "Read measured values" function of the Guided Fault Finding for the respective control module, depending on the vehicle version and equipment. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
- Depending on the vehicle version, the seat heating for the front passenger seat can be switched off after a certain period of time if it is detected that the seat is empty. Refer to the Owner's Manual.
- There are different versions of the Front A/C Display Control Head -E87-. Refer to the Parts Catalog. The various versions of the Front A/C Display Control Head -E87- (version -A- with a "Low" and "Mid" A/C system, or version -B- with a "Mix" and "High" A/C system) can be recognized by the symbols on the buttons for vehicles with "seat heating" and "seat ventilation" optional equipment, for example. Refer to the Owner's Manual.
- When the seat heating or seat ventilation is switched on, the function indicator lamps in the respective buttons illuminate. Refer to the Owner's Manual.
- The seat heating or seat ventilation level is set on the Front A/C Display Control Head -E87-. This setting is transmitted to the respective control module via the data bus. The target temperatures for the different seat heating settings are stored in the relevant control modules. Depending on the version of the control module and the vehicle date of manufacture, the specified temperature for the seat heating can differ with the same setting on the Front A/C Display Control Head -E87-. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
Rear Seat Heating
Components which participate in the activation of the rear seat heating
Rear seat heating activation depends on the version and equipment of the vehicle.
Vehicles without Rear A/C Display Control Head -E265-
Note
Depending on vehicle equipment, there are different versions of the A/C system for the Audi Q7. Make sure to use the correct version and pay attention to the allocation of different components. Refer to → Chapter "A/C System Versions" and Parts Catalog.
Note
- For vehicles with a "Low" A/C system (without Rear A/C Display Control Head -E265-, version -A or B-), the seat heating for the rear seats is adjusted using the Left Seat Heating Button -E653- and the Right Seat Heating Button -E654-, for example (different designations depending on the version and the vehicle date of manufacture. Refer to → Wiring diagrams, Troubleshooting & Component locations).
- The Left Seat Heating Button -E653--A- and the Right Seat Heating Button -E654--B- are installed in the rear center console trim on a vehicle with a "Low" A/C system (without Rear A/C Display Control Head -E265-, different designations depending on the version and the vehicle date of manufacture. Refer to → Wiring diagrams, Troubleshooting & Component locations).
- The Left Rear Bench Seat Heating Element -Z10-, the Left Rear Backrest Heating Element -Z11-, the Right Rear Bench Seat Heating Element -Z12- and the Right Rear Backrest Heating Element -Z13- are activated by the Rear Seat Heating Control Module -J786- or by the Seat Heating Control Module -J882--C- (different designations depending on the version and date of manufacture of the vehicle. Refer to → Wiring diagrams, Troubleshooting & Component locations).
- The control module ( Rear Seat Heating Control Module -J786- or module Seat Heating Control -J882-) -C- is currently installed under the left C-pillar trim panel. Refer to → Wiring diagrams, Troubleshooting & Component locations.
- The control module ( Rear Seat Heating Control Module -J786- or module Seat Heating Control -J882-) -C-) is currently not OBD-capable. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" function and refer to → Wiring diagrams, Troubleshooting & Component locations. The rear seat heating is only activated when it is enabled by the Vehicle Electrical System Control Module -J519- accordingly.
Vehicles with a Rear A/C Display Control Head -E265-
Note
Depending on vehicle equipment, there are different versions of the A/C system for the Audi Q7. Make sure to use the correct version and pay attention to the allocation of different components. Refer to → Chapter "A/C System Versions" and Parts Catalog.
For vehicles with a Rear A/C Display Control Head -E265- (version -A- with a "Mid" or "Mix" A/C system, or version -B- with a "High" A/C system), the seat heating for the rear seats is adjusted via the Rear A/C Display Control Head -E265-. The Rear A/C Display Control Head -E265- activates the seat heating for the rear seats depending on the vehicle equipment and vehicle version. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" function and refer to → Wiring diagrams, Troubleshooting & Component locations.
- A Start/Stop System is available for certain engines for this vehicle. For vehicles with a Start/Stop System, the seat heating can be switched off for the time in which the Stop function is active (to protect the Battery -A-). The setting for seat heating activation remains stored in the Rear A/C Display Control Head -E265-. After the engine was restarted using the Start function, the seat heating is switched on again. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
Note
- Seat heating activation can differ, depending on the vehicle version. Refer to → Wiring diagrams, Troubleshooting & Component locations.
- Depending on the vehicle version and equipment, the various information regarding the seat heating activation (setting transmitted by the Rear A/C Display Control Head -E265-, the specified and actual temperature of the seat, etc.) is displayed differently in various measured values in different control modules. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
- If there is a condition in which the rear seat heating cannot be switch on (for example, there is a short circuit in the connection to a seat heating element, interruption in the power supply to the respective control module, etc.), it is stored as a malfunction in the Rear A/C Display Control Head -E265-, in the Vehicle Electrical System Control Module -J519-, in the Front A/C Display Control Head -E87-, in the Data Bus on Board Diagnostic Interface -J533-, in the Driver Side Rear Seat Adjustment Control Module -J876- or in the Passenger Side Rear Seat Adjustment Control Module -J877- (depending on the vehicle version and vehicle equipment). For this vehicle, information stating that the DTC memory in the respective control module must be read out may not be sent via the data bus to the Rear A/C Display Control Head -E265-. Refer to 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.
- The function test for the seat heating activation is described in Guided Fault Finding for the respective control module (different versions of the Rear A/C Display Control Head -E265-, version -A- with a "Mid" or "Mix" A/C system, or version -B- with a "Mid" or "Mix" A/C system), depending on the vehicle version and equipment. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
- If, for example, the voltage at terminal "30" measured at the Vehicle Electrical System Control Module -J519- falls below a value stored in the Vehicle Electrical System Control Module -J519-, the seat heating output is reduced or switched off completely in order to reduce the load on the Generator -C-. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
- In the "Read measured values" function of Guided Fault Finding, the Rear A/C Display Control Head -E265- indicates what level the seat heating is set at. The seat heating activation, the actual and specified seat temperature, the actual current supplied to the seat heating, etc. are displayed in the "Read measured values" function of the Guided Fault Finding for the respective control module, depending on the vehicle version and equipment. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
- Depending on the vehicle version, the rear seat heating can be switched off after a certain period of time if it is detected that a seat is empty. Refer to the Owner's Manual.
