Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
VEHICLES WITH AUTOMATIC CLIMATE CONTROL, Climatronic Control Module -J255
The Climatronic Control Module -J255-
A head area heater is installed as optional equipment for the A3 Cabrio. On vehicles with a head area heater there is an additional vent installed in the seat and in the A/C control head the Climatronic Control Module -J255- there are additional buttons -1 and 2- to switch on and off the head area heater. Additional information. Refer to HEAD AREA HEATER .
Different versions of the Climatronic Control Module -J255- A/C control head on vehicles with and without a high voltage system. Refer to the Parts Information. On a Climatronic Control Module -J255- for vehicles with a high voltage system with the additional function to activate the shut-off valves -N541-, -N542-, the Electrical A/C Compressor -V470- etc. but without the possibility to activate the parking heater installed as retro-fit or the A/C Compressor Regulator Valve -N280-.
Different versions for vehicles with a high voltage system for example for Europe or North America. On vehicles for North American is for example an A/C Pressure/Temperature Sensor -G395- is installed instead of the A/C Compressor Regulator Valve -G805- and another version of the Electrical A/C Compressor -V470- (with the A/C Compressor Control Module -J842-) is installed. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function and refer to the Parts Information.
The following illustration shows the Climatronic Control Module -J255- A/C control head without the button for switching on and off the head area heater.
- A - Climatronic Control Module -J255- Control Head for Vehicles without Seat Heating
- 1 - Driver Side Temperature Preset Regulator
- 2 - Display
- 3 - Knob for Fresh Air Blower -V2-
- 4 - A/C
Button for A/C Compressor
- Illuminated LED indicates the "A/C compressor on" function is selected
- 5 - Front Passenger Side Temperature Preset Regulator
- 6 -
Button for Setting the Upper Air Distribution
- Illuminated LED indicates the "Upper air distribution" function is selected
- Different versions (with different symbols on the button). Refer to the Parts Information
- 7 -
Button for Setting the Center Air Distribution
- Illuminated LED indicates the "Center air distribution" function is selected
- 8 -
Button for Setting the Lower Air Distribution
- Illuminated LED indicates the "Lower air distribution" function is selected
- 9 -
Rear Window Defogger Button
- Illuminated LEDs indicate the "Rear window defogger on" function is selected.
- By pressing and holding the button the rear window defogger can be continuously switched on. Refer to Rear Window Defogger -Z1-, CHECKING - If the rear window defogger button is pressed for a long period of time when turning on the rear window defogger, the rear window defogger remains switched on until the button is pressed again or the ignition is switched off. Refer to the Owner's Manual. .
- 10 -
Recirculation Mode Button
- Illuminated LEDs indicate the "recirculated-air mode" function is selected.
- The "recirculated-air mode" function is canceled when the defrost mode button (air to the windshield) is pressed
- 11 -
Defrost Mode Button
- Illuminated LED indicates the "defrost mode" function is selected.
- Different versions (with different symbols on the button). Refer to the Parts Information
- 12 - Auto
Button for Automatic A/C System Control
- Illuminated LED indicates the "Automatic control" function is selected
- B - Climatronic Control Module -J255- Control Head for Vehicles with Seat Heating
- 1 - Driver Side Temperature Preset Regulator
- 2 - Display
- 3 - Knob for Fresh Air Blower -V2-
- 4 - A/C
Button for A/C Compressor
- Illuminated LED indicates the "A/C compressor on" function is selected
- 5 - Front Passenger Side Temperature Preset Regulator
- 6 -
Left Seat Heating Button
- Illuminated LED indicates the level selected.
- The selected level is set back one unit after a preset time. Refer to FRONT SEAT HEATING, CHECKING - 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. .
- 7 -
Button for Setting the Upper Air Distribution
- Illuminated LED indicates the "Upper air distribution" function is selected
- Different versions (with different symbols on the button). Refer to the Parts Information
- 8 -
Button for Setting the Center Air Distribution
- Illuminated LED indicates the "Center air distribution" function is selected
- 9 -
Button for Setting the Lower Air Distribution
- Illuminated LED indicates the "Lower air distribution" function is selected
- 10 -
Rear Window Defogger Button
- Illuminated LEDs indicate the "Rear window defogger on" function is selected.
- By pressing and holding the button the rear window defogger can be continuously switched on. Refer to Rear Window Defogger -Z1-, CHECKING - If the rear window defogger button is pressed for a long period of time when turning on the rear window defogger, the rear window defogger remains switched on until the button is pressed again or the ignition is switched off. Refer to the Owner's Manual. .
- 11 -
Recirculation Mode Button
- Illuminated LEDs indicate the "recirculated-air mode" function is selected.
- The "recirculated-air mode" function is canceled when the defrost mode button (air to the windshield) is pressed
- 12 -
Defrost Mode Button
- Illuminated LED indicates the "defrost mode" function is selected.
- Different versions (with different symbols on the button). Refer to the Parts Information
- 13 - Auto
Button for Automatic A/C System Control
- Illuminated LED indicates the "Automatic control" function is selected
- 14 -
Right Seat Heating Button
- Illuminated LED indicates the level selected.
- The selected level is set back one unit after a preset time. Refer to FRONT SEAT HEATING, CHECKING - 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. .
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.