REFRIGERANT CIRCUIT, DRAINING
Refrigerant is never to be allowed to escape into the atmosphere, but rather it is to be extracted from the refrigerant circuit using an extractor or service station. The drained refrigerant will be locally recycled or is send to an environment-recycling place to the manufacturer (different or additional laws may apply in individual companies). For this reason, bring vehicle to a workshop that has the necessary tools and where the work can be performed by qualified personnel. Refer to General Information .
Reason
If refrigerant R134a is released into the environment, it enhances the green house effect.
Note. Refrigerant R134a has far less of a greenhouse effect than R12. Because R-134a does not contain chlorine atoms, the major catalyst in ozone depletion, -R134a- has no ozone depletion potential. Depletion of the ozone layer in the upper atmosphere is however only brought about by the splitting of carbon-chlorine bonds (as is the case, for example, with refrigerant R12).
After discharging the air conditioner, disconnect harness connector from A/C Compressor Regulator Valve -N280- or from High Pressure Sensor -G65-.
Reason
A/C Compressor Regulator Valve is then no longer activated and compressor runs at idle. Compressor is designed such that lubrication of compressor components is guaranteed by way of an internal oil circuit at idle (provided there is sufficient refrigerant oil in the compressor).
FRONT CONDENSATION WATER DRAIN, CHECKING
- Disconnect condensation water drain hose -A-, refer to «FRONT CONDENSATION WATER DRAIN HOSE»(ref-491706-S00628282902012073100000) and check the following
Check condensation water drain of heating & A/C unit -B- for soiling (e.g. using a piece of wire) and clean it if necessary.
Check clearance of the insulation mat (in engine compartment, not present in all vehicles) via opening -B- in floor plate -C- or out from engine compartment, it must be large enough so that it does not contact the door -D-, permitting condensation water to drain out from condensation water drain opening.
Scheme 3
Check installation position of floor mat -E-, it must not constrict (compress) cross section of condensation water drain hose -A-.
Note. Door -D- (valve) must not be obstructed by wax or underbody sealer, it must close properly. Door -D- can also be checked via the engine compartment (from above or below) with engine installed, depending on version.
- For complaints of moisture in passenger compartment, check the following components as well as condensation water drains
Water drain openings in plenum chamber, refer to PLENUM CHAMBER WATER DRAIN, CHECKING AND CLEANING .
Water drain from fresh air intake shaft, refer to FRESH AIR INTAKE HOUSING .
Plenum chamber cover and wind cowl for damage and correct installation. Refer to Removal and Installation .
Dust and pollen filter for soiling and correct installation, refer to DUST AND POLLEN FILTER .
Forced air extraction vents in luggage compartment, refer to VENT FRAME, CHECKING .
Actuation and function of fresh/recirculating air door (visual inspection e.g. under instrument panel with cover removed), refer to RECIRCULATION DOOR MOTOR V113 (and also via the "output Diagnostic Test Mode (DTM)" function on vehicles with Comfort version A/C system, if necessary) using Vehicle Diagnosis, Testing and Information System VAS5051 in the "Guided Fault Finding" function.
Signal detecting windshield wiper operation at Climatronic Control Module -J255- (e.g. via the "Read measuring value block" function on vehicles with Comfort version A/C system) using Vehicle Diagnosis, Testing and Information System VAS5051 in the "Guided Fault Finding" function.
- Check air outlet temperature from evaporator via measured values of Evaporator Vent Temperature Sensor -G263- under the operating conditions indicated by customer with the following setting on Climatronic Control Module (e.g. via the "Read measuring value block" function) using Vehicle Diagnosis, Testing and Information System VAS5051 in the "Guided Fault Finding" function.
Temperature preselect Lo for driver's and front passenger's side (on Comfort version) or temperature switch at Cold stop (on Basic version).
Intermediate fresh air blower speed (approximately 7 volts), check using Vehicle Diagnosis, Testing and Information System VAS5051 in the "Guided Fault Finding" function.
Operating mode Fresh Air.
Check measured value of Evaporator Vent Temperature Sensor (e.g. via the "Read measuring value block" function) of the Vehicle Diagnosis, Testing and Information System VAS5051 in the "Guided Fault Finding" function. If measured value is too low (at an ambient temperature above 0 °C, colder than 0 °C for extended period of time) or too high (greater than e.g. 10 °C even though A/C system is operating without problems), observe notes for testing cooling output, refer to TEST REQUIREMENTS and Vehicle Diagnosis, Testing and Information System VAS5051 in the "Guided Fault Finding" function.
PLENUM CHAMBER WATER DRAIN, CHECKING AND CLEANING
Note. The draining of water from plenum chamber may be impaired by deposits (leaves, diverse tree needles etc.) accumulating in plenum chamber water drains. The water level in the plenum chamber then rises if the vehicle is taken to an automatic car wash or in the event of heavy rain and water penetrates into fresh air intake housing via the water drain valve -arrow- installed in the fresh air intake housing, is drawn in from there through the fresh air blower along with the air conveyed and blown on to evaporator. Both water drain grommets -A- installed in plenum chamber can be cleaned from above (only with plenum chamber cover removed) or from below (with left or right wheel housing liner removed), depending on vehicle. Remove plenum chamber cover to clean plenum chamber, both water drain grommets -B- can be cleaned e.g. with vehicle on a lift via both wheel housings from below with the wheel housing liner removed. If water drain grommets -B- are blocked by leaves and pine needles, it may cause the drains to freeze up in winter and water can no longer drain out. After a short drive, heat emitted from engine and exhaust system melts the ice in the drains again and water may drain off again before vehicle arrives at the workshop. Water drain grommets -B- are installed into body drain openings -A- from above, water drain grommets can be removed and installed also from below when the wheel housing liner has been removed
FRONT CONDENSATION WATER DRAIN HOSE
Note. Only one condensation water drain hose is installed on this vehicle (at right on heating & A/C unit in passenger compartment). There is a door -D- on the outlet opening on the condensation water drain hose -A-, check this door, it must not be jammed and must close. Condensation water drain -A- ends in engine compartment at lower right beneath bulkhead. Depending on version of vehicle (engine and transmission configuration), condensation water drain can be checked via the engine compartment (from above or below). For clear illustration, condensation water drain -A- is depicted with assemblies removed. Door -B- on condensation water drain must not be obstructed by wax or underbody sealer, it must close properly.
- Condensation Drain, checking, refer to «FRONT CONDENSATION WATER DRAIN, CHECKING»(ref-491706-S39168639912012073100000) .
Removing
Remove instrument panel trim under glove compartment. Refer to Removal and Installation .
Remove lower right A pillar trim. Refer to Removal and Installation .
If necessary, carefully fold back floor mat far enough that condensation water drain hose -A- is visible.
Scheme 4
Cover area of floor mat under condensation water drain hose -A- with absorbent paper (so that any water present does not flow on to or below floor mat).
Remove condensation water drain hose -A-.
Installing
- Check the following before installing the condensation water hose -A
Check clearance of the insulation mat (in engine compartment) via opening -B- in floor plate -C-, it must be large enough so that it does not contact the door -D-, permitting condensation water to drain out from condensation water drain opening.
Check installation position of floor mat -E-, it must not constrict (compress) cross section of condensation water drain hose -A-.
Condensation water drain of heating & A/C unit -B- for soiling (e.g. using a piece of wire) and clean it if necessary.
Insert condensation water drain into opening in lower floor plate -C-.
Connect condensation water drain hose -A- on proper side to condensation water drain of heating & A/C unit -B- (opening of door -D- must be at bottom) and secure the connection if necessary using a clamp.
Check installation position of floor carpet, it must not constrict (compress) cross section of condensation water drain hose -A-.
Install the instrument panel trim under glove compartment. Refer to Removal and Installation .
Note. Condensation water hose must fit securely on connection of heating & A/C unit. Condensation water hose to valve (door) must not be kinked or pinched.
CONDENSATION WATER DRAIN
Note. The condensation water drain is installed in area of left rear fender and can be checked from outside without having to remove the components for it.
Checking
Check valve -A- from below (with vehicle on a lift). Valve must not be obstructed by wax or underbody sealer and must close properly.
Check condensation water drain of rear heating & A/C unit -F- for soiling (e.g. using a piece of wire) and clean it if necessary.
Note. Condensation water hose -D- must fit securely on connection of heating & A/C unit -F-. Condensation water hose -D- to valve -A- must not be kinked or pinched. Depending on production time period, condensation water hose -D- is secured by a hose clamp -E- or a cable tie to condensation water drain of rear heating & A/C unit -F-.
Removing
Switch off ignition.
Slide condensation water drain -B- into vehicle interior from below (disengage condensation water drain -B- from rear floor plate -C- to do so).
Bring rear heating & A/C unit into service position, refer to REAR HEATING & A/C UNIT, BRINGING INTO SERVICE POSITION .
Disconnect condensation water drain hose -A- from condensation water drain of heating & A/C unit -D-.
Scheme 5
Note. Depending on production time period, condensation water drain hose -A- is secured by a hose clamp or a cable tie to condensation water drain of heating & A/C unit -D-.
Installing
Secure condensation water drain hose -A- using a hose clamp -B- to condensation water drain of heating & A/C unit -D-.
When installing heating & A/C unit, make sure that condensation water drain is guided into opening -C- of floor plate.
Install heating & A/C unit and other removed components.
Pull condensation water drain hose -A- outward from below through opening in rear floor plate -C-.
Secure condensation water drain hose -B- on rear floor plate -C- from below as depicted, make sure that condensation water drain hose is not twisted when doing this.