Rear Heating & A/C Unit

Rear Heating & A/C Unit

Disassemble and assemble the rear A/C unit, refer to => [ Rear HVAC Unit ] Rear HVAC Unit.

Removing

- Discharge the refrigerant circuit.

- Switch off ignition.

- Dissipate pressure in coolant circuit by opening cap at coolant expansion tank.

- Disconnect refrigerant lines from rear expansion valve, refer to => [ Rear Expansion Valve, Disconnecting and Connecting ] Rear Expansion Valve, Disconnecting and Connecting.

- Bring rear heating & A/C unit into service position, refer to => [ Rear Heating & A/C Unit, Bringing Into Service Position ] Rear Heating & A/C Unit, Bringing Into Service Position.

- Mark both coolant hoses - A - and - B - to rear heater core - C - (risk of interchange).





- Clamp off both coolant hoses - A - and - B - to rear heater core - C - (e.g. using hose clamps up to 25 mm dia. (3094)).

- Cover the area below heating & A/C unit, where any coolant flowing out may reach, with absorbent paper (so that any coolant still present will not flow on and into heating & A/C unit or on to floor mat).

- Place a container under both connections to heater core - C - and disconnect both coolant hoses.

- Remove rear heating & A/C unit.

• When removing, hold heating & A/C unit so that no coolant can flow out of heater core - C -.

Installing

Installation is carried out in the reverse order while noting the following:

- Bleed rear heater core - C - before or when connecting both coolant hoses - A - and - B - in the same way as described for replacing rear heater core in => [ Heater Core ] Heater Core.

- Bleed cooling circuit. Refer to => [ Coolant System, Bleeding ] Coolant System, Bleeding.

- Evacuate refrigerant circuit and charge it anew.

- Check DTC memory of Climatronic Control Module (J255) (and of Rear A/C Display Control Head (E265)) and erase any DTCs displayed using Vehicle Diagnosis, Testing and Information System VAS5051 in the "Guided Fault Finding" function.

- If necessary, perform a basic setting and output diagnostic test mode on the A/C system using Vehicle Diagnosis, Testing and Information System VAS5051 in the "Guided Fault Finding" function.

- Operate the A/C system after filling the refrigerant circuit, refer to => [ A/C System, Operating after Filling Refrigerant Circuit ] A/C System, Operating after Filling Refrigerant Circuit.

• Note the information regarding operating the A/C system after filling.

- If necessary, check function of A/C system using Vehicle Diagnosis, Testing and Information System VAS5051 in the "Guided Fault Finding" function.