2022-2026 Audi Exterior Lights Moisture Accumulation TSB

This Technical Service Bulletin (TSB) 2012749/18 from Audi provides detailed information regarding Audi exterior lights moisture accumulation. It outlines two distinct situations that can lead to moisture inside headlights, taillights, side repeater lights, turn signals, and fog lights, affecting various 2022-2026 Audi models.

Symptoms of Exterior Light Moisture

The TSB identifies two primary situations for Audi exterior lights moisture:

Situation 1: Physical Condensation

This refers to condensation forming on the inside of the lenses. It is described as an optical phenomenon that does not affect the performance of the lights or cause corrosion. This type of condensation can occur on any headlamp, fog lamp, or taillight and is considered normal for the open-system design of these lights, which allows air circulation for pressure equalization. Examples of this include:

• 0607010103 Headlights: Drops forming on left-side lens
• 0607010104 Headlights: Drops forming on right-side lens
• 0607010307 Turn signal front / side: Drops forming side left
• 0607010308 Turn signal front / side: Drops forming side right
• 0607010403 Tail light: Drops forming left side
• 0607010404 Tail light: Drops forming right side
• 0607010503 Fog lights: Drops forming left side
• 0607010504 Fog lights: Drops forming right side

Situation 2: Water Ingress/Leaks

This situation involves water marks or large droplets inside the lenses, indicating a leak. This can be caused by open covers, a damaged cap seal, or similar issues. This is a fault that requires attention. Examples of this include:

• 0603030401 Side repeater lights: Left reflector tarnished
• 0603030408 Side repeater lights: Right reflector tarnished
• 0603030701 Brake light / third brake light: Left reflector tarnished
• 0603030706 Brake light / third brake light: Right reflector tarnished
• 0607010101 Headlights: Water in left-side headlight
• 0607010102 Headlights: Water in right-side headlight
• 0607010303 Turn signal front / side: Water in light side left
• 0607010304 Turn signal front / side: Water in light side right
• 0607010401 Tail light: Water in left-side light
• 0607010402 Tail light: Water in right-side light
• 0607010501 Fog lights: Water in left-side light
• 0607010502 Fog lights: Water in right-side light

Important Warnings for Owners

Owners should be aware of specific conditions and limitations regarding Audi exterior lights moisture:

• Situation 1: Physical condensation is NOT a fault which is covered under warranty. This is an optical phenomenon that does not affect performance or cause corrosion.
• If your concern is related to Situation 1 (physical condensation), do not replace parts. Replacing the headlight or taillight will not solve the issue.
• NOTICE: If a headlight/taillight is replaced due to water ingress/leaks, physical condensation can still occur on the new part. This is not considered renewed water ingress and does not justify replacing the part again.

Diagnosis and Trigger Conditions

Physical condensation (Situation 1) typically occurs in wet weather or due to temperature differences. For example, residual heat from the engine can warm the light from the back while the outside air cools the lens, causing humidity to condense. Driving through a car wash or using steam cleaners can also amplify this phenomenon. For physical condensation, the light emission surface should clear after driving for 10-30 minutes at an average speed of 50 mph with low beams on. Other internal surfaces may still show condensation, which is normal.

For Situation 2 (leaks), the presence of water marks or large droplets, even after sufficient ventilation, indicates a problem with the light's seal or housing.

Repair Procedure Summary

For any customer complaint about Audi exterior lights moisture, technicians are instructed to use a checklist, test plan flowchart, and reference photos to determine the cause.

• For Situation 1 (Physical Condensation): No repair is needed. The process of physical condensation should be explained to the customer. Replacing parts will not resolve this condition.

• For Situation 2 (Water Ingress/Leaks):

  1. If a leak is apparent, the technician must use the test plan to establish the cause.
  2. The headlight/taillight should be dried with filtered, oil-free compressed air.
  3. The component causing the complaint must be replaced.
  4. Technicians must check for corrosion on connectors or connections of any control units.
  5. If, after these steps, the customer still reports leaks or large droplets, the headlight/taillight should be replaced.

All repairs must be documented following the instructions in TSB 2061922: "94 How to properly document optical concerns for headlights and taillights." Photos of the moisture are required to be submitted to DOC-IT if a warranty claim is made.

Warranty Information

This TSB is informational only and does not automatically apply to Audi Warranty. For any warranty claim related to Audi exterior lights moisture, the complaint must be thoroughly documented with a complete checklist, the test plan, and photos. If a claim is submitted but the component is determined to be functioning correctly according to manufacturer testing, the costs may be charged back.

Source: NHTSA ID 11017625