2021 Audi A6/A7 Water Ingress in Footwell TSB 2060335/1

Symptoms of Water Ingress

Owners of 2019-2021 Audi A6, A6 Avant, A6 allroad, and A7 models may experience several issues related to water ingress. The primary complaint is "Water is in the footwell area." This can lead to broader problems, including "malfunctions of various infotainment features" and the display of "various error messages in the instrument cluster."

During workshop inspections, technicians have confirmed the presence of water under the carpet and verified the reported error messages. Additionally, electrical connectors in the affected areas may show signs of corrosion due to moisture exposure.

Technical Background

According to Audi Technical Service Bulletin 2060335/1, the root cause of this water ingress is an incorrect bonding of the sound absorber located inside the longitudinal member. This allows water to penetrate the vehicle's interior. Figure 1 in the bulletin illustrates the exact location of the water intrusion, while Figure 2 (ETKA drawing 803-000) shows the sound absorber's position within the longitudinal member.

Diagnosis and Trigger Conditions

Before performing the repair, technicians must confirm that the water intrusion originates from the sound absorber in the longitudinal member. This repair specifically addresses that root cause. If water intrusion is present but not from this source, further diagnosis outside the scope of TSB 2060335/1 is required.

To diagnose the 2021 Audi A6 water ingress, the following steps are performed:

1. Access Longitudinal Member: Any necessary underbody covers are removed to gain access to the longitudinal member plugs (Figure 3). These plugs are located on the lower right and left sides of the vehicle.
2. Check for Leaks: Plugs 1 and 5 on the longitudinal member are removed to check for water ingress in the footwell. If a water leak is observed from the lower longitudinal member after removing these plugs, the sealing measure outlined in this bulletin should be performed on the affected side. Both sides of the vehicle should be checked, and repaired if necessary.
3. Inspect Cabin Floor: The areas on the inside of the cabin floor where water intrusion is likely (indicated by arrows 1, 2, and 3 in Figure 4) are inspected. If water is found in the interior after lifting the floor covering, the floor covering is propped up, and the interior is thoroughly dried.
4. Electrical Connector Check: Electrical connectors under the floor covering are checked for corrosion. Any corrosion found must be repaired according to the Elsa repair manual.

Repair Procedure Summary

The repair for the 2021 Audi A6 water ingress issue involves sealing the sound absorber in the longitudinal member to prevent further water entry. The procedure is as follows:

1. Remove Wheel Housing Liner: The front wheel housing liner is removed from the affected side of the vehicle. A plug (indicated by the red arrow in Figure 5) is removed to create an opening for sealer application. Another opening (yellow arrow in Figure 5) is used to inspect the area with a borescope.
2. Seal Sound Absorber: The sound absorber within the longitudinal member (Figure 7) is completely sealed using 1k adhesive sealant, part number D 511 500 A2.
3. Inject Sealant: The sealant is injected through the opening in the wheelhouse (shown in Figure 6 and Figure 8) using a VAG1628 cartridge gun or an equivalent tool.
4. Distribute Sealant: An amount of sealer sufficient to cover the entire surface and perimeter of the sound absorber is applied (Figure 9). This sealant is then spread using a gloved finger (Figure 10) or, alternatively, a modified brush (Figure 11). If a brush is used, care must be taken to ensure no brush fragments are left inside the longitudinal member.
5. Verify Sealer Coverage: A borescope, such as the VAS 6748 B, is inserted into the opening (yellow arrow in Figure 12) to visually confirm complete and even sealer coverage (Figure 13).
6. Apply Cavity Preservative: Once the sealant has fully cured, the inside of the longitudinal member is coated with cavity preservative D 330 KD2 A1 (or D 321M16M2) through the same opening (Figure 14).
7. Replace Plugs: The original plugs (plugs 1 and 5) that were removed are replaced with new plugs, part number 8K0 805 267, which feature an integrated drain (Figure 15).

Required Tools and Parts

To address the 2021 Audi A6 water ingress and similar issues in the A7, specific parts and tools are required:

Parts:

• Cavity Preservative: D 330 KD2 A1 or D 321M16M2 (Quantity: 1)
• 1k Adhesive Sealant: D 511500A2 (Quantity: 1)
• Fasteners, Bolts, Nuts, and Screws: As needed, per ETKA/ELSA Repair Manual
• Plug: 1K0899183 (Quantity: 2)
• Drain Tube Grommet (New Plug): 8K0805267 (Quantity: 4)

Tools:

• Cartridge Gun: VAG1628 (or equivalent)
• Borescope: VAS 6748 B (or equivalent)
• Wiring Harness Repair Set: VAS 1978A
• Diagnostic System: VAS 6160/VAS 6150 (Windows 10 with current ODIS Service version)

Important Warnings

Owners should be aware of specific conditions related to this TSB:

• "Only perform the following repair if water intrusion is confirmed as coming from the sound absorber in the longitudinal member. The following repair will only correct this root cause. If the water intrusion is confirmed but the longitudinal members are not at issue, continue diagnosis outside the scope and instruction provided in this TSB."
• "If the vehicle is outside any warranty, this Technical Service Bulletin is informational only."

Warranty Information

This repair is covered under Audi's warranty for vehicles up to 48 months or 50,000 miles. The specific details for warranty claims are:

• Claim Type: 110
• Service Number: 5079
• Damage Code: 0010
• Claim Comment: "As per TSB #2060335/1"

Labor Operations and Time Units (TU):

Repair longitudinal member – one side:

• Wheel remove and reinstall: 4405 1900 (See SRT with associated operations)
• Front-wheel housing liner remove and reinstall: 6616 1900 (See SRT with associated operations)
• Gain access to longitudinal member opening, remove plugs and reseal sound absorber: 5079 9999 (30 TU)
• Front floor covering loosen - 1 side. Dry interior: 7041 9999 (120 TU)

Repair longitudinal member – both sides:

• Remove and install 2 wheels: 4405 2000 (See SRT with associated operations)
• Front-wheel housing liners remove and reinstall: 6616 2000 (See SRT with associated operations)
• Gain access to both the right and left longitudinal member openings, remove plugs and reseal sound absorbers – both sides: 5079 9999 (50 TU)
• Body cavity conserved: 5101 7501 (See SRT with associated operations)
• Front floor covering loosens – both sides. Dry interior: 7041 9999 (210 TU)

In all cases:

• Inspect electrical connectors and wiring for damage and repair as necessary: 9709 41XX (Use the appropriate labor operation corresponding with the number of wires repaired; See SRT with associated operations)

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

Source: NHTSA ID 10178440