A/C Unit
A/C Unit
• On removal, mark the various control motors and the associated connecting elements between door and motor to prevent mix-ups with connecting elements of other control motors.
• If connecting elements are interchanged, actuators with incorrect connecting elements do not reach their specified end position, and fault "upper or lower limit exceeded" may be displayed in DTC memory after basic setting.
• When removing, mark the various connectors to the control motors (risk of interchange with connectors and control motors of identical construction).
• Various connectors of identical construction are present on wiring harness of heating & A/C unit, apply identifying marks on connectors before disconnecting (risk of interchange).
• The control motor housings are currently identical (except the Control Motor for the Rear Vent (V112)), but the shaft of each motor is different due to the different connecting elements so if they are switched, it may not be possible to install the connecting element.
• Various control motors are installed on the A/C unit and in the air intake unit. They have different electrical values (e.g. potentiometer with an adjustment range of 120° or 150°) and are different in the part number index (at start of production, without index, with index "A" or "B"). For this reason, mark the control motors prior to removing them (risk of interchange).
• Apply a small amount of Grease (G 000 150) to the connecting element guides, as well as the pins and toothed segments on the door levers.
• The A/C unit may only be removed when the refrigerant circuit has been discharged. Bring the vehicle to a workshop that has the necessary tools and where the work can be performed by qualified personnel => A/C System with Refrigerant R134a.
• Heating & A/C unit, removing and installing => [ A/C Unit ] A/C Unit.
• Prior to disassembly, remove the heat exchanger for heating from the A/C unit => [ Evaporator and Heat Exchanger Housing ] Evaporator and Heat Exchanger Housing and disconnect the plug from the Evaporator Vent Temperature Sensor (G263).
• There are different versions of the heat exchanger and the associated coolant pipes. In model year 2006, the seal between connections on the heat exchanger and coolant pipes was converted from an axial/radial seal - A - and - B - to a radial seal - D - and - E - as a running change, make sure the version is correct when replacing the heat exchanger and O-ring seal - -C- is in the correct installation position. -
• On vehicles with a radial seal on coolant pipes - B - to the heat exchanger, a plastic clamp - A - may also be installed instead of screw clip.
• The A/C unit may only be removed when the refrigerant circuit has been discharged. Bring the vehicle to a workshop that has the necessary tools and where the work can be performed by qualified personnel => A/C System with Refrigerant R134a.
• Heating & A/C unit, removing and installing => [ A/C Unit ] A/C Unit.
1 Evaporator and heat exchanger housing
• Different versions in vehicles with steering on the left or right.
• Disassembling and assembling => [ Evaporator and Heat Exchanger Housing ] Evaporator and Heat Exchanger Housing
2 Air distribution housing
• Versions vary for vehicles with the Climatronic Control Module (J255) A/C control head in the "Comfort" or "Basic" version.
• Removed and install components that are installed => [ A/C Unit Electrical Components ] A/C Unit Electrical Components
• Remove and then install electrical components and the corresponding connecting elements from the air distributor housing => [ Air Intake Unit Electrical Components and Connecting Elements ] Air Intake Unit Electrical Components and Connecting Elements
• In model year 2008, there is a rolling change in the threading at the screw points of the air distributor housing to the central tube of the instrument panel (the cast metal inserts have been eliminated, the screws go directly into the plastic), ensure the proper screw version during installation.
3 Wiring harness for heating and A/C unit
- When removing, mark the various connectors (risk of interchange with connectors and control motors of identical construction).
• Versions vary for vehicles with the Climatronic Control Module (J255) A/C control head in the "Comfort" or "Basic" version.
• Different versions in vehicles with steering on the left or right.
• Various connectors of identical construction are present on wiring harness of heating & A/C unit, apply identifying marks on connectors before disconnecting (risk of interchange).
4 Clip
5 Screw