87 Unpleasant Odor Is Coming From The Heating And Ventilation System (GROUP 87, NO. 22-25)

87 UNPLEASANT ODOR IS COMING FROM THE HEATING AND VENTILATION SYSTEM

TECHNICAL SERVICE BULLETIN

SERVICE INFORMATION

87 22 25 2010146/17 April 16, 2022. Supersedes Technical Service Bulletin Group 87 number 21-13 dated May 4, 2021, for reasons listed below.

CONDITION

Customer states:

• There is an unpleasant, musty odor coming from the heating and ventilation system.
• The odor usually occurs when the vehicle has been sitting unused for five hours or more.
• The odor usually occurs within 20 to 60 seconds after the vehicle is started.

TECHNICAL BACKGROUND

Condensation, which is a normal condition in all A/C systems, can cause a musty odor.

If the odor is noticeable in the vehicle when the engine is not turned on, the cause may be mold and mildew in the passenger compartment, and not be related to the A/C system. All other possible sources of the odor must be investigated before this bulletin can be performed. Before proceeding, consider the following:

• The evaporator housing drain must be open and free of debris.
• The cabin must be sealed with no water ingress into the passenger compartment.
• The plenum drains must be clear and free of debris.

The pollen filter must be clean and free of moisture.

PRODUCTION SOLUTION

Not applicable.

SERVICE

Contaminants are effectively neutralized by the Aircomatic® II Ultrasonic Climate System Cleaner (VAS 6189A) and Airco-Clean® Ultrasonic Air Conditioning Treatment (VAS 6189/1). No other cleaning methods are permitted.

1. If the vehicle is equipped with an in-cabin pollen filter (such as in the A3, A6, and Q7), remove the pollen filter element and reinstall its cover before proceeding.
2. Start the engine.
3. Adjust the following climate control settings (Figure 1):
   • Set the temperature to its lowest setting.
   • Set the fan speed to its lowest setting.
   • Set the airflow direction to the dash vents only.
   • Activate recirculation and ECON modes.
4. Thoroughly shake a 100ml bottle of treatment and empty it into the filling chamber (Figure 2).
5. Connect the outlet tube (Figure 3).
6. Place the cleaning unit into the passenger side footwell, ensuring that the unit is as level as possible.
7. Connect the unit power cord, and route it through one of the windows, which should be slightly open (Figure 4). All other windows and the sunroof should be completely closed.
8. Turn the unit on and position the outlet tube so that the vapor is drawn into the recirculation air intake (generally in the passenger side footwell area; see appropriate repair information for exact location).
9. Close all doors. The atomized cleaning fluid will begin to come out of the vents. After 15-20 minutes, the treatment is complete and the machine stops automatically.
10. If the vehicle is equipped with a four-zone climate control system with 2 evaporators (such as Q7 and A8), repeat the procedure for the rear A/C unit before proceeding. Use the same A/C settings listed above. Position the outlet tube toward the fresh air inlet vent for the rear unit. The configuration of the Q7 is shown to the right (Figure 5).
11. After the procedure, air the vehicle out for approximately ten minutes.
12. Check the Aircomatic® manual for instructions for unit maintenance after each use.

WARRANTY

• This bulletin is allowed only once per vehicle. The vehicle must be within its first 12 months of service and under NVLW.
• There must be an original customer concern of the specified odor symptom on the repair order for this bulletin to apply. Adding this procedure on is not permitted.
• Subsequent applications, should they become necessary, will be the customer's responsibility.
• Replacement of the pollen filter under warranty is not allowed within the performance of this procedure. The pollen filter is covered only where specified at the appropriate maintenance interval.

When the procedure applies to vehicles under warranty, use the following:

All warranty claims submitted for payment must be in accordance with the Audi Warranty Policies and Procedures Manual  Claims are subject to review or audit by Audi Warranty.

REQUIRED PARTS AND TOOLS

Always check with your Parts Department and/or ETKA for the latest information and parts bulletins. 

Part Number	Part Description	Quantity
See ETKA	Fasteners, Bolts, Nuts, and Screws as needed per the Repair Manual	See ETKA/ELSA
VAS 6189/1	Airco-Clean® Ultrasonic Air Conditioning Treatment (100ml bottle)	1 bottle (For models with a single evaporator) 2 bottles (For models with two evaporators)

Tool Number	Tool Description
VAS 6189B
	Aircomatic® II Ultrasonic Climate System Cleaning unit

ADDITIONAL INFORMATION

All parts and service references provided in this TSB (2010146) are subject to change and/or removal.

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