Evaporator Drain Tube: Testing and Inspection
Front Condensation Water Drain, Checking
• Disconnect condensation water drain hose - A -, refer to => [ Front Condensation Water Drain Hose ] Front Condensation Water Drain Hose and check the following:
- Check condensation water drain of heating & A/C unit - B - for soiling (for example, 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.
- Check installation position of floor mat - E -, it must not constrict (compress) cross section of condensation water drain hose - A -.
• 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 ] Procedures.
- Water drain from fresh air intake shaft, refer to => [ Fresh Air Intake Housing ] Fresh Air Intake Housing.
- Plenum chamber cover and wind cowl for damage and correct installation.
- Dust and pollen filter for soiling and correct installation, refer to => [ Dust and Pollen Filter ] Service and Repair.
- Forced air extraction vents in luggage compartment, refer to => [ Vent Frame, Checking ] Vent Frame, Checking.
- Actuation and function of fresh/recirculating air door (visual inspection for example, under instrument panel with cover removed), refer to => [ Recirculation Door Motor ] 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) (for example, 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 (for example, 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 (for example, 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 (32 °F), colder than 0 °C (32 °F) for extended period of time) or too high (greater than for example, 10 °C (50 °F) even though A/C system is operating without problems), observe notes for testing cooling output, refer to => [ Test Requirements ] Test Requirements and Vehicle Diagnosis, Testing and Information System VAS5051 in the "Guided Fault Finding" function.