2021 Audi A/C Unpleasant Odor TSB 2010146/15

Symptoms of an Unpleasant Odor

Owners of affected Audi vehicles, including the 2021 Audi e-tron, may notice an unpleasant, musty odor coming from the heating and ventilation system. This odor commonly appears after the vehicle has been sitting unused for five hours or more. Typically, the smell becomes noticeable within 20 to 60 seconds after the engine is started.

Technical Background and Diagnosis

Condensation is a normal occurrence in all automotive A/C systems. However, this moisture can sometimes lead to a musty odor due to microbial growth. Before addressing the odor with the prescribed cleaning procedure, technicians must rule out other potential causes.

Several checks are required to ensure the issue is related to the A/C system and not other factors. These include verifying that the evaporator housing drain is open and free of debris, confirming the cabin is sealed against water ingress, and ensuring the plenum drains are clear. Additionally, the pollen filter must be clean and dry. If the odor is present when the engine is off, it might indicate mold or mildew in the passenger compartment, which would require a different investigation.

Repair Procedure Summary

Audi Technical Service Bulletin 2010146/15 outlines a specific procedure to neutralize contaminants causing the unpleasant odor. This involves using the Aircomatic® II Ultrasonic Climate System Cleaner (VAS 6189A) in conjunction with Airco-Clean® Ultrasonic Air Conditioning Treatment (VAS 6189/1). No other cleaning methods are permitted for this repair.

The process begins by preparing the vehicle. If the vehicle is equipped with an in-cabin pollen filter (such as in the A3, A6, and Q7 models), the filter element must be removed, and its cover reinstalled. The engine is then started, and the climate control settings are adjusted to the lowest temperature and fan speed, with airflow directed only to the dash vents. Recirculation and ECON modes must be activated.

Next, a 100ml bottle of the Airco-Clean® treatment is thoroughly shaken and emptied into the filling chamber of the Aircomatic® unit. The unit's outlet tube is connected, and the device is placed in the passenger side footwell, ensuring it is level. The power cord is routed through a slightly open window, with all other windows and the sunroof completely closed.

The Aircomatic® unit is then turned on, and its outlet tube is positioned so that the vapor is drawn into the recirculation air intake, typically in the passenger side footwell area. All vehicle doors are closed. The atomized cleaning fluid will begin to emit from the vents. The treatment takes approximately 15 to 20 minutes, after which the machine automatically stops. For vehicles with a four-zone climate control system and two evaporators (like the Q7 and A8), the procedure must be repeated for the rear A/C unit, positioning the outlet tube towards the fresh air inlet vent.

After the cleaning process is complete, the vehicle must be aired out for approximately ten minutes. Technicians are also instructed to consult the Aircomatic® manual for unit maintenance instructions after each use.

Required Parts and Tools

To perform the cleaning procedure described in TSB 2010146/15, specific parts and tools are required:

• Airco-Clean® Ultrasonic Air Conditioning Treatment (100ml bottle), Part Number: VAS 6189/1. One bottle is needed 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.
• Any necessary fasteners, bolts, nuts, and screws should be referenced in ETKA/ELSA per the repair manual.

Warranty Information

This bulletin's procedure is allowed only once per vehicle, provided the vehicle is within its first 12 months of service and covered under the New Vehicle Limited Warranty (NVLW). An original customer concern describing 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. Any subsequent applications, if necessary, will be the customer's responsibility.

Replacement of the pollen filter under warranty is not covered as part of this procedure. The pollen filter is only covered where specified at the appropriate maintenance interval. For warranty claims, use the following codes:

• Claim Type: 1SP
• Service Number: 8760
• Damage Code: 0049
• Labor Operations: All models except R8.

Diagnostic time includes 10 TU for road test prior to service procedure (0121 0002) and 10 TU for road test after service procedure (0121 0004). Claims must adhere to the Audi Warranty Policies and Procedures Manual and are subject to audit.

Important Warnings

• Do NOT use any other cleaning methods besides the Aircomatic® II Ultrasonic Climate System Cleaner and Airco-Clean® Ultrasonic Air Conditioning Treatment as specified in this bulletin. Using alternative methods will not resolve the 2021 Audi e-tron unpleasant odor and may cause further issues.
• Replacement of the pollen filter under warranty is NOT allowed within the performance of this procedure. Owners should be aware that this specific repair does not cover a new pollen filter.

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Source: NHTSA ID: 10174559