Control Module HVAC: Description and Operation

Climatronic Control Module (J255)

- Climatronic control module, removing and installing, refer to=> [ Climatronic Control Module (J255) ] Climatronic Control Module (J255).

• On vehicles with heating (without A/C system), a Climatronic control module is installed instead of the A/C control head. There is no Instrument Panel Interior Temperature Sensor (G56) and no Interior Temperature Sensor Fan (V42) installed in the Climatronic control module heater control head.

• The Climatronic control module, can currently be exchanged as usual, component protection is not active at this time. Check using Vehicle diagnosis, testing and information system (VAS5051B) in the "Guided Fault Finding" function.

• If a Climatronic control module with active component protection (anti-theft system) is installed in a different vehicle, only the functions necessary for vehicle safety can be selected, comfort functions can no longer be selected. Check using Vehicle diagnosis, testing and information system (VAS5051B) in the "Guided Fault Finding" function.

• Component protection (anti-theft system, introduction not yet finalized) can only be cancelled by entering specific vehicle data using Vehicle diagnosis, testing and information system (VAS5051B) in the "Guided Fault Finding" function.

• When replacing a Climatronic control module, observe exact allocation. Refer to Electronic Parts Catalog (ETKA). Different versions, with or without seat heating switch, with different temperature unit (°C or °F) on temperature setting rotary switch, rotary switches with black or silver surface.

• If a new Climatronic control module was installed and basic setting was not performed, A/C system regulation is limited and this is displayed in the DTC memory as a malfunction. After installing the Climatronic control module, perform a basic setting to the A/C (heater) according to Vehicle diagnosis, testing and information system (VAS5051B) in the "Guided Fault Finding" function.

• The Climatronic control module buttons and rotary switches are lit with light diodes (LEDs, that cannot be replaced).

• The function and indicator lights in the buttons and in the rotary switches cannot be replaced separately.

• If the Instrument Panel Interior Temperature Sensor (G56) measurement is incorrect, check Climatronic control module intake grille trim (it must not be closed) and function of the Interior Temperature Sensor Fan (V42) using Vehicle diagnosis, testing and information system (VAS5051B) in the "Guided Fault Finding" function.

• The selected functions are displayed when the function lights in the various Climatronic control module buttons, rotary switches or display fields light up.

• From May 2007, a A/C air distribution housing with a door in the air outlet to the defroster vents in the instrument panel without a side cut-out is gradually being installed. With the introduction of the door without the side cut-out, the Climatronic control module (J255) is also changed (due the missing cut-out, the door must be open wider to direct the same amount of air to the windshield). Refer to the Electronic Parts Catalog. The Climatronic control module, part number "8J0 820 043" through index "AA" only may be installed only in vehicles which have a A/C air distribution housing with a door in the air outlet to the defroster vents in the instrument panel without a side cut-out (exception: vehicles that will only be driven in tropical regions). Refer to => [ A/C Air Distribution Housing Defroster Outlet Door ] A/C Air Distribution Housing Defroster Outlet Door. With the Climatronic control module part number "8J0 820 043" from index "AB" the "adaptation" function, the version of the door in the air outlet to the defroster vents in the instrument panel) can be entered (Climatronic control module adapting) using Vehicle diagnosis, testing and information system (VAS5051B) in the "Guided Fault Finding" function.

• 5 cylinder vehicle may only have heater controls, part number 8J0 819 043 starting with index "D". Refer to the Electronic Parts Catalog and Vehicle diagnosis, testing and information system (VAS5051B) in the "Guided Fault Finding" function.

• 5 cylinder vehicle may only have A/C controls, part number 8J0 820,043 starting with index "D". Refer to the Electronic Parts Catalog and Vehicle diagnosis, testing and information system (VAS5051B) in the "Guided Fault Finding" function.

• Starting with model year 2011, A/C system control heads-part number 8J0 820,043, beginning with index "BA"-shall be gradually installed. These control modules possess an added function for the expanded change indicator that is part of the efficiency indicator for the on-board computer. Therefore, no A/C control head-part number 8J0 820 043 through index "AS"-is allowed to be installed in a vehicle with an expanded on-board computer's change indicator. The A/C control heads-part number 8J0 820 043 beginning with index "BA" are easy to identify because of the silver (chrome-plated) knobs. Refer to Electronic Parts Catalog (ETKA), Vehicle diagnosis, testing and information system (VAS5051B) in the "Guided Fault Finding" function and the vehicle owner's manual.

• Starting with model year 2011, heating system control heads-part number 8J0 819 043, beginning with index "H"-shall be gradually installed. These control modules possess an added function for the expanded change indicator that is part of the efficiency indicator for the on-board computer. Therefore, no heater control head-part number 8J0 819 043 through index "AS"-is allowed to be installed in a vehicle with an expanded on-board computer's change indicator. The heater control heads-part number 8J0 819 043 beginning with index "H" are easy to identify because of the silver (chrome-plated) knobs. Refer to Electronic Parts Catalog (ETKA), Vehicle diagnosis, testing and information system (VAS5051B) in the "Guided Fault Finding" function and the vehicle owner's manual.

• A/C (heater) control head, removing and installing, refer to => [ Climatronic Control Module (J255) ] Climatronic Control Module (J255).