A/C - Unpleasant/Musty Odors From The A/C System
87 Unpleasant odor from heating and ventilation system
87 12 27
2010146/9
April 24, 2012.
Supersedes Technical DIAGNOSIS AND REPAIR Group 87 number 10 - 03 dated June 16, 2010 for reasons listed below.
Affected Vehicles
Condition
Unpleasant "musty" odor from heating and ventilation system. Odor mainly occurs after vehicle has been sitting unused at least 5 hours and within
20 to 60 seconds after vehicle is first started.
Technical Background
Condensate is a normal condition in all A/C systems. If odor is noticeable without engine started, this may be due to mold and mildew in the
passenger compartment, not from the A/C system. All other possible sources of unpleasant odor must be addressed before performing this Technical
DIAGNOSIS AND REPAIR. Consider the following conditions before proceeding:
^ Evaporator housing drain must be open and free of debris.
^ Cabin must be sealed with no water ingress into the passenger compartment.
^ Plenum drains must be clear and free of debris.
^ Pollen filter must be clean and free of moisture.
Contaminants are effectively neutralized using the Aircomatic(R) II Ultrasonic Climate System Cleaner (VAS 6189A) and Airco-Clean(R)
Ultrasonic Air Conditioning Treatment (VAS 6189/1). All other cleaning methods are no longer permitted.
Production Solution
Not applicable.
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Service
1. If the vehicle is equipped with a pollen filter that is located inside the cabin such as in the A3, A6 and Audi Q7 then the pollen filter element
will need to be removed and its cover reinstalled before performing this procedure.
2. Start engine.
3. Set climate control temperature to its lowest setting. Set fan speed to its lowest setting. Set airflow direction to the dash vents only. Activate
recirculation and ECON modes.
4. Thoroughly shake a 100ml bottle of treatment and empty the bottle into the filling chamber.
5. Connect the outlet tube.
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6. Place the cleaning unit into the passenger footwell, making certain that the unit is as level as possible. Connect the power cord and route it
through a slightly opened window. The remaining windows and sunroof should be completely closed.
7. Switch unit on and position the outlet tube such that the vapor is drawn into the recirculation air intake, generally in the passenger footwell
area. Refer to the appropriate repair information for exact location. Close all doors. The atomized cleaning fluid will begin coming out of the
vents. After about 15-20 minutes, the treatment stops automatically.
8. If the vehicle is an Audi Q7 with 4 zone climate control, the rear A/C unit is to be treated as well. Repeat the procedure for the rear A/C unit.
Use the same A/C settings as were used for the front A/C unit. Position the outlet tube toward the vent on the left of the rear compartment.
9. Air out the vehicle after the procedure for about 10 minutes.
10. Check the Aircomatic manual for instructions for unit maintenance after each use.
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Warranty
Required Parts and Tools
Additional Information
All parts and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service
manuals for the latest information.
