Heating & A/C Unit Components - Manually Regulated A/C System
Heating & A/C Unit Components - Manually 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
• Different versions of heating & A/C unit in vehicles with manually and automatically regulated A/C system. Refer to Electronic Parts Catalog (ETKA).
• 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 & A/C unit, removing and installing, refer to => [ A/C Unit ] A/C Unit.
• 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 A/C System Controls / Base Plate
• Different versions of base plate on vehicles with manually regulated A/C system and without A/C system (with heating system only). Refer to Electronic Parts Catalog (ETKA).
• Removing and installing, refer to=> [ Heater Controls ] Heater Controls.
3 A/C System Controls, A/C Control Module (J301)
• Different versions depending on vehicle equipment (with and without Driver Heated Seat Adjuster (E94) and Front Passenger Heated Seat Adjuster (E95) ). Refer to Electronic Parts Catalog (ETKA).
• Removing and installing, refer to=> [ Heater Controls ] Heater Controls.
• Function, electrical test using Vehicle diagnosis, testing and information system (VAS5051B) in "Guided Fault Finding".
4 Heat Core For Heater Unit
• Removing and installing, refer to=> [ Heater Core ] Heater Core.
5 Temperature Regulator Door Motor (V68)
• With Temperature Regulator Door Motor Position Sensor (G92).
• 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.
6 Left Footwell Vent Temperature Sensor (G261)
• This sensor is installed only at beginning of production (discontinued as running change).
• Measured value of this sensor is not evaluated by A/C control module (J301) , a malfunction at left footwell vent temperature sensor is not detected.
• Removing and installing, refer to=> [ Left Footwell Vent Temperature Sensor (G261) ] Left Footwell Vent Temperature Sensor (G261).
7 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).
8 Flexible Shaft
• To gear mechanism with curved washer for activation of air distribution doors.
• Removing and installing, refer to => [ Air Distribution Flexible Shaft ] Air Distribution Flexible Shaft.
9 To Gear Mechanism With Curved Washer For Activation Of Air Distribution Doors
• Do not remove, adjustment cannot be reproduced.
10 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).
• On version for manually regulated A/C system, the recirculation door motor does not have potentiometer installed, therefore this motor is always actuated in one direction (fresh air or recirculated air mode). The direction of control motor rotation is reversed by switching the positive and negative on the outputs of A/C Control Module (J301). The A/C control module detects via the current strength, which flows via the control motor, that is has reached its end position.
• The recirculation door motor does not have a potentiometer, therefore a malfunction at the control motor or in its wire connection is not always detected by A/C control module (J301).
• Checking function using Vehicle diagnosis, testing and information system (VAS5051B) in "Guided Fault Finding".
• Removing and installing, refer to => [ Fresh/Recirculation Air Door Motor (V154)/(V113) ] Fresh/Recirculation Air Door Motor (V154)/(V113).
11 Intake Housing With Fresh/Recirculating Air Door
• Different versions of the air intake shroud in vehicles with manually and automatically regulated A/C system. Refer to Electronic Parts Catalog (ETKA).
• Removing and installing, refer to => [ Air Intake Housing With Fresh/Recirculating Air Door ] Air Intake Housing With Fresh/Recirculating Air Door.
12 Fresh Air Blower (V2)
• Different versions of Fresh Air Blower in vehicles with manually and automatically regulated A/C system. Refer to Electronic Parts Catalog (ETKA).
• Removing and installing, refer to => [ Fresh Air Blower (V2) ] Service and Repair.
13 Fresh Air Blower Series Resistor With Fuse (N24)
• Removing and installing, refer to => [ Fresh Air Blower Series Resistor with Fuse (N24) ] Service and Repair.
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 10-pin Connector
• To vehicle wiring harness.
16 Evaporator Vent Temperature Sensor (G263)
• Removing and installing, refer to => [ Evaporator Vent Temperature Sensor (G263) ] Evaporator Vent Temperature Sensor (G263).
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.