2010-2022 Audi Unpleasant HVAC Odor Technical Service Bulletin

Symptoms

Owners of various 2010-2022 Audi models may experience an "unpleasant, musty odor coming from the heating and ventilation system." This odor typically becomes noticeable after the vehicle has been sitting unused for five hours or more. The musty smell usually appears within 20 to 60 seconds after the vehicle is started. If you notice an Audi e-tron unpleasant odor from your vents, this TSB may apply to your vehicle.

Diagnosis and Trigger Conditions

The primary cause of the unpleasant odor is often condensation, a normal byproduct of all air conditioning systems, which can lead to a musty smell. However, technicians must first rule out other potential sources of odor before performing the TSB procedure. These include:

• Mold and mildew in the passenger compartment, especially if the odor is present when the engine is off.
• A blocked evaporator housing drain, which should be open and free of debris.
• Water ingress into the passenger compartment, indicating the cabin is not properly sealed.
• Clogged plenum drains, which must be clear and free of debris.
• A dirty or moist pollen filter, which should be clean and dry.

Repair Procedure Summary

Audi Technical Service Bulletin 2010146/16 outlines a specific procedure to neutralize contaminants causing the odor using specialized equipment and treatment. The process involves:

1. Pollen Filter Removal: If the vehicle is equipped with an in-cabin pollen filter (e.g., in A3, A6, Q7 models), it must be removed, and its cover reinstalled before proceeding.
2. Vehicle Preparation: The engine is started, and specific climate control settings are applied. This includes setting the temperature to its lowest, fan speed to its lowest, airflow direction to dash vents only, and activating recirculation and ECON modes (as shown in Figure 1 of the TSB).
3. Treatment Application: A 100ml bottle of Airco-Clean® Ultrasonic Air Conditioning Treatment (VAS 6189/1) is thoroughly shaken and emptied into the filling chamber of the Aircomatic® II Ultrasonic Climate System Cleaning unit (VAS 6189B) (Figure 2).
4. Unit Setup: The outlet tube is connected to the cleaning unit (Figure 3), and the unit is placed level in the passenger-side footwell. The unit's power cord is routed through a slightly open window (Figure 4), ensuring all other windows and the sunroof are completely closed.
5. Cleaning Cycle: The unit is turned on, and the outlet tube is positioned to direct vapor into the recirculation air intake. All doors are closed, and the atomized cleaning fluid will begin to emit from the vents. The cleaning process takes approximately 15-20 minutes, after which the machine automatically stops.
6. Multi-Zone Systems: For vehicles with a four-zone climate control system and two evaporators (such as the Q7 and A8), the procedure must be repeated for the rear A/C unit. The outlet tube is positioned towards the fresh air inlet vent for the rear unit (Figure 5).
7. Post-Treatment: After the cleaning cycle, the vehicle must be aired out for approximately ten minutes.
8. Tool Maintenance: Technicians are instructed to consult the Aircomatic® manual for proper unit maintenance after each use.

Required Tools or Parts

To perform this service, specific Audi-approved tools and parts are required:

• Airco-Clean® Ultrasonic Air Conditioning Treatment (100ml bottle): Part Number VAS 6189/1. One bottle is required for models with a single evaporator, and two bottles for models with two evaporators.
• Aircomatic® II Ultrasonic Climate System Cleaning unit: Tool Number VAS 6189B.
• Fasteners, bolts, nuts, and screws as needed, as per the repair manual and ETKA.

Warranty Information

This Technical Service Bulletin (TSB 2010146/16) specifies strict conditions for warranty coverage:

• Limited Coverage: This procedure is allowed only once per vehicle.
• Eligibility: The vehicle must be within its first 12 months of service and covered under the New Vehicle Limited Warranty (NVLW).
• Customer Concern: An original customer concern regarding the specified odor symptom must be documented on the repair order for this bulletin to apply. Adding this procedure without a customer complaint is not permitted.
• Owner Responsibility: Any subsequent applications of this procedure, should they become necessary, will be the customer's responsibility.
• Pollen Filter: Replacement of the pollen filter is not covered under warranty as part of this procedure. It is only covered if specified at the appropriate maintenance interval.

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

• Claim Type: 1SP
• Service Number: 8760
• Damage Code: 0049
• Labor Operations (TU - Technical Units):
  • All models except R8:
    • A/C clean - All models with single evaporator: 8701 2999 (70 TU)
    • A/C clean - All models with two evaporators: 8701 3099 (135 TU)
  • R8:
    • A/C clean: 8701 9999 (210 TU)
• Diagnostic Time: GFF (No allowance - 0 TU)
• Road Test: No allowance for pre-service or post-service road tests (0 TU).
• Claim Comment: As per TSB #2010146/16

All warranty claims must comply with the Audi Warranty Policies and Procedures Manual and are subject to review or audit.

Source: NHTSA ID: 10193251