2021-2024 Audi V6 TFSI Coolant Loss TSB

Audi has issued Technical Service Bulletin (TSB) 2070349/4 to address instances of Audi V6 TFSI coolant loss from the coolant pump in various 2021-2024 models. This bulletin provides diagnostic and repair procedures for technicians to accurately identify and resolve the issue. It supersedes a previous bulletin, Group 19 number 23-46, dated December 12, 2023, with updated instructions and technical background.

Symptoms of Coolant Loss

Owners of affected Audi V6 TFSI vehicles may experience several indicators pointing to a coolant system issue. These symptoms include:

• "Coolant loss/leak."
• Illumination of the "Coolant warning lamp."
• The "Engine warning lamp on" in the instrument cluster.

These signs suggest a problem with the cooling system, most commonly originating from the coolant pump.

Associated Fault Codes

In some cases, a leaking coolant pump can lead to secondary issues, triggering specific diagnostic trouble codes (DTCs). Technicians may find the following event memory entry logged:

• P0299: Turbo/Super Charger Underboost

This DTC occurs when the N649 switch valve becomes contaminated with coolant from the leaking pump, affecting its proper operation and leading to underboost conditions.

Diagnosis and What to Expect

When diagnosing Audi V6 TFSI coolant loss, technicians will first confirm the coolant pump as the source of the leak. It is crucial to distinguish actual leaks from normal occurrences. For example, small traces of coolant (up to 3 ml over 100 hours of operation) on the drip cup are considered normal due to seal lubrication and cooling, and do not warrant a complaint. Similarly, dried deposits on vacuum connections are not a definitive sign of a leak.

The diagnostic process involves:

1. Precisely locating the leak.
2. Thoroughly cleaning and drying any coolant traces.
3. Filling the cooling system to its maximum level.
4. Performing visual checks at idle and up to 2500 rpm to observe for leaks.
5. Checking the entire cooling system for leaks according to the Audi Workshop Manual.

Important Warnings for Owners

Audi's TSB 2070349/4 includes critical information for both technicians and owners:

• Normal Coolant Traces: "Due to lubrication/cooling of the seal, up to 3 ml may escape over the course of 100 hours of operation. This is quite normal and does not constitute a reason for a complaint." Owners should be aware that minor coolant residue might not indicate a fault.
• Misleading Deposits: "Dried deposits on vacuum connection are not a clear indication of a leak." These deposits alone should not be interpreted as proof of a leak.
• No Leak Detected: If, after initial checks, "No further coolant leak can be detected: continue to observe without replacing any parts." This prevents unnecessary component replacements.
• Warranty Coverage: "If the vehicle is outside of any warranty, this Technical Service Bulletin is informational only." This means repairs for this issue may not be covered by Audi if the vehicle is out of warranty.

Repair Procedure Summary

If a coolant leak is confirmed, the repair procedure outlined in TSB 2070349/4 focuses on replacing the faulty component. Key steps include:

1. Leak Confirmation: Reassessing the suspected leak after initial cleaning and checks. If a leak is detected again, the component(s) causing the leak will be replaced.
2. Documentation: Technicians are instructed to document leaks with photos or video. If the coolant pump is found to be leaking, its production date must also be photographed.
3. Component Replacement: The primary repair involves removing and installing the coolant pump if it is confirmed faulty.
4. System Checks: Additional labor operations may include checking and topping up coolant, cleaning, performing visual checks, and checking the entire cooling system for leaks. Battery charging may also be performed if necessary.

The TSB specifies various labor operations and associated codes for warranty claims, such as Service Number 1950 and Damage Code 0050. All warranty claims must adhere to the Audi Warranty policies and Procedures Manual, referencing TSB 2070349/4.

Owner Action and Warranty Information

If you are experiencing Audi V6 TFSI coolant loss or any of the related symptoms, it is recommended to schedule an appointment with an authorized Audi service center. Provide them with the symptoms you've observed and mention Technical Service Bulletin 2070349/4. While the TSB provides a repair path, warranty coverage will depend on your vehicle's warranty status. Always consult with your dealer regarding specific coverage and repair costs.

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Source: NHTSA ID: 11007304