Heating & A/C Unit Components - Automatically Regulated A/C System
Heating & A/C Unit Components - Automatically Regulated A/C System
• The design of the heating & A/C unit is largely the same on vehicles with manually and automatically regulated A/C systems, the differences can be found in the operation of the doors, in fresh air blower (V2) and in the number and version of the motors
Observe notes for control and regulation of components in passenger compartment. Refer to=> [ A/C System Control and Regulation Components Inside Passenger Compartment ] A/C System Control and Regulation Components Inside Passenger Compartment.
• Air duct in air conditioner and in vehicle, refer to => [ Air Routing and Distribution in Passenger Compartment ] Air Routing and Distribution In Passenger Compartment.
• Heating & A/C unit, removing and installing, refer to => [ A/C Unit ] A/C Unit.
1 - A/C Unit With Evaporator
• May only be removed when refrigerant circuit has been removed. Bring vehicle to a workshop that has the necessary tools and in which the work can be performed accordingly by qualified personnel.
• Heating and A/C unit, removing and installing, refer to => [ A/C Unit ] A/C Unit.
• Heating and A/C unit, disassembling and assembling, refer to => [ A/C Unit ] A/C Unit.
• Clean air conditioning system evaporator with Ultrasound A/C Cleaner (VAS 6189). Refer to=> [ Evaporator, Cleaning ] Evaporator, Cleaning.
2 - Defroster Door Motor (V107)
• With Defroster Door Motor Position Sensor (G135).
• Lever color identification: blue.
• Removing and installing, refer to => [ Defroster Door Motor (V107) ] Defroster Door Motor (V107).
• This motor is fastened on the right on air distributor housing in vehicles with right-side steering.
3 - Left Footwell Vent Temperature Sensor (G261)
• Removing and installing, refer to => [ Left Footwell Vent Temperature Sensor (G261) ] Left Footwell Vent Temperature Sensor (G261).
4 - Central Air Door Motor (V70)
• With Central Door Motor Position Sensor (G112).
• Removing and installing, refer to => [ Central Air Door Motor (V70) ] Central Air Door Motor (V70).
5 - Auxiliary Air Heater Heating Element (Z35) (with Auxiliary Air Heater Control Module (J604) )
• The electric auxiliary air heater is available in different versions. On vehicles equipped with a diesel engine built through November 2006 (running change) the control of the auxiliary air heater heating element via the auxiliary air heater control module. Check using Vehicle diagnosis, testing and information system (VAS5051B) in "Guided Fault Finding". On diesel vehicles built from November 2006 (running change) have a 3-stage Auxiliary Air Heater Heating Element (Z35) which is controlled by a relay from the engine control module. Check using Vehicle diagnosis, testing and information system (VAS5051B) in "Guided Fault Finding".
• Check the function of the auxiliary air heater control module, perform Guided Fault Finding using Vehicle diagnosis, testing and information system (VAS5051B) in "Guided Fault Finding".
• Removing and installing, refer to => [ Auxiliary Air Heater Heating Element (Z35) with Control Module (J604) ] Auxiliary Air Heater Heating Element (Z35) With Control Module (J604).
6 - Heat Core For Heater Unit
• Removing and installing, refer to => [ Heater Core ] Heater Core.
7 - Left Temperature Door Motor (V158)
• With Left Temperature Door Potentiometer/Actuator (G220).
• Lever color identification: white.
• Removing and installing, refer to => [ Left Temperature Door Motor (V158)/Temperature Regulator Door Motor (V68) ] Left Temperature Door Motor (V158)/Temperature Regulator Door Motor (V68).
• The name for this control motor in Guided Fault Finding and in the wiring diagram is different on vehicles with a manually and an automatically regulated A/C system.
• On vehicles with manually regulated A/C system, this control motor operates both temperature doors (the right and left temperature doors are connected to each other via the shaft). On vehicles with an automatically regulated A/C system, the left and right temperature doors are each actuated by one control motor.
8 - Airflow Door Motor (V71)
• With Back Pressure Door Motor Position Sensor (G113).
• Removing and installing, refer to => [ Airflow Door Motor (V71)/Recirculation Door Motor (V113) ] Airflow Door Motor (V71)/Recirculation Door Motor (V113)
• To the end of model year 2007, the Airflow door motor (V71) is being discontinued as a running change, on vehicles without the Airflow door motor the air flow door (fresh air door) is actuated via a curved washer and lever of the Recirculation door Motor (V113). Refer to=> [ Recirculation Door Motor (V113) ] Recirculation Door Motor (V113). Therefore note the correct allocation of the Climatronic control module (J255) , if the allocation or the adaptation is not OK this is detected during basic setting and stored as a malfunction. Refer to Electronic Parts Catalog (ETKA) and Vehicle diagnosis, testing and information system (VAS5051B) under "Guided Fault Finding".
9 - Recirculation Door Motor (V113)
• With Recirculation Door Motor Position Sensor (G143).
• Removing and installing, refer to => [ Recirculation Door Motor (V113) ] Recirculation Door Motor (V113).
• Different versions of recirculation door motor in vehicles with manually and automatically regulated A/C system. Refer to Electronic Parts Catalog (ETKA).
• Different versions of recirculation door motor on vehicles with automatically regulated A/C system, with and without Airflow door motor (V71) (see item 7) and Electronic Parts Catalog.
10 - Right Footwell Vent Temperature Sensor (G262)
• Removing and installing, refer to => [ Right Footwell Vent Temperature Sensor (G262) ] Right Footwell Vent Temperature Sensor (G262).
11 - Intake Housing With Recirculating Air Back Pressure Door (Fresh Air Door)
• Removing and installing, refer to => [ Air Intake Housing ] Air Intake Housing.
12 - Fresh Air Intake Duct Temperature Sensor (G89)
• Removing and installing, refer to => [ Fresh Air Intake Duct Temperature Sensor (G89) ] Fresh Air Intake Duct Temperature Sensor (G89).
• From model year 2006, the Fresh Air Intake Duct Temperature Sensor has been gradually discontinued, on vehicles without this temperature sensor, only the Climatronic Control Module (J255) with part number as of index M is or may be installed.
• On vehicles without Fresh Air Intake Duct Temperature Sensor, a Climatronic Control Module (J255) with part number up to index L installed enters a DTC into the DTC memory.
13 - Fresh Air Blower Control Module (J126) and Fresh Air Blower (V2)
• Removing and installing, refer to => [ Fresh Air Blower Control Module (J126) and Fresh Air Blower (V2) ] Fresh Air Blower Control Module (J126) and Fresh Air Blower (V2).
• Different versions, as of model year 2007 the Fresh Air Blower Control Module (J126) and Fresh Air Blower (V2) can each be replaced separately (running change in production). Refer to=> [ Fresh Air Blower Control Module (J126) and Fresh Air Blower (V2) ] Fresh Air Blower Control Module (J126) and Fresh Air Blower (V2) and Electronic Parts Catalog.
• Fresh Air Blower Control Module (J126) is installed in Fresh Air Blower (V2).
• Checking, use Vehicle diagnosis, testing and information system (VAS5051B) under "Guided Fault Finding".
14 - Dust and Pollen Filter
• Removing and installing, refer to => [ Dust and Pollen Filter ] Service and Repair.
• Follow the replacement intervals.
• As a replacement part, the dust and pollen filter is available in different versions (with and without activated charcoal element). Refer to Electronic Parts Catalog (ETKA).
• For information regarding for version with an activated charcoal insert, refer to => [ Dust and Pollen Filter with Activated Charcoal Insert ] Description and Operation.
15 - Evaporator Vent Temperature Sensor (G263)
• Removing and installing, refer to => [ Evaporator Vent Temperature Sensor (G263) ] Evaporator Vent Temperature Sensor (G263).
16 - Right Temperature Door Motor (V159)
• With Right Temperature Door Potentiometer/Actuator (G221).
• Removing and installing, refer to => [ Right Temperature Door Motor (V159) ] Right Temperature Door Motor (V159).
17 - Coolant Pipes To Heater Core
18 - Grommet
• For sealing off opening for coolant and refrigerant lines through bulkhead to engine compartment.
• A foam spacer bracket is installed between grommet and heating & A/C unit.
• Installing, refer to=> [ A/C Unit ] A/C Unit.
19 - Condensation Water Drain Connection
• Condensation water drain valve, checking, removing and installing, refer to=> [ Condensate Drain Hose, Checking ] Condensate Drain Hose, Checking.
20 - Expansion Valve
• Refrigerant lines, disconnecting and reconnecting, refer to=> [ Expansion Valve Refrigerant Lines, Disconnecting and Connecting ] Expansion Valve Refrigerant Lines, Disconnecting and Connecting.
• Removing and installing, refer to=> [ Expansion Valve ] Expansion Valve.
• After switching off the A/C compressor in this vehicle, it may take a relatively long time for the pressure on the high pressure side to decrease. This is because the expansion valve is cold and the pressure on the low pressure side increases quickly after shutting the compressor off, then the expansion valve closes and the refrigerant flows slowly to the low pressure side.