2021 Audi e-tron Coolant Marks on Filler Cap TSB

Symptoms of Coolant System Issues

Owners of 2021 Audi vehicles, including the Audi e-tron, may notice specific signs indicating a potential issue with their cooling system. These symptoms often prompt a visit to the dealership for diagnosis.

Common customer statements include:

• "MIL on with low coolant level."
• "Coolant leak under front of the vehicle."

Workshop Findings and Technical Background

When a vehicle presents with these symptoms, technicians often observe "Coolant marks around coolant filler cap for cooling system/around coolant expansion tank." These marks are a key indicator that the TSB addresses.

The technical background explains that the pressure relief valve within the cooling system's filler cap can sometimes create the impression that the valve is malfunctioning, even when it is not. This TSB clarifies that these marks do not automatically mean the cap is faulty.

Diagnostic and Repair Procedure Summary

The TSB provides specific guidance for technicians. If coolant marks are present, the primary step is to thoroughly check the filler cap of the cooling system. This check must be performed according to the procedures outlined in Audi's Elsa diagnostic system.

Crucially, if the filler cap passes this diagnostic test, technicians are instructed "do not replace the cap, continue the fault finding." This prevents unnecessary part replacements and ensures that the root cause of any actual coolant leak or low level is properly identified. The presence of Audi e-tron coolant marks alone is not sufficient for cap replacement.

Required Tools or Parts

To properly diagnose and address the issue described in this TSB, technicians utilize specialized tools. These tools are essential for accurately testing the cooling system and its components.

The following tools are specified:

• VAG1274B: Cooling system tester
• VAG1274/8: Cooling system tester- Adapter
• VAG1274/9: Cooling system tester- Adapter
• VAG1274B/15: Cooling system tester- Adapter

These tools help determine if the cooling system's pressure relief valve is functioning correctly.

Important Warnings for Owners

Owners should be aware of the warranty implications for this specific issue. This Technical Service Bulletin, identified as 19 21 22 2046712/3, is "informational only and not applicable to any Audi Warranty." This means that any diagnostic or repair work related to the Audi e-tron coolant marks or associated symptoms may not be covered under standard Audi warranty terms.

If you are experiencing symptoms like "MIL on with low coolant level" or visible coolant leaks, it is important to consult with your Audi service center to understand the diagnostic process and potential costs.

TSB Revision History

This Technical Service Bulletin has undergone several revisions to ensure accuracy and include updated information. The current version, Revision 3, was published on July 26, 2021.

Key revisions include:

• Revision 3 (July 26, 2021): Revised header to add Model Year 2021 and updated part numbers in the "Required Parts and Tools" section.
• Revision 2 (July 14, 2017): Revised "Required Parts and Tools" to add a part number.
• Revision 1 (February 3, 2017): Initial publication of the TSB.

This bulletin supersedes Technical Service Bulletin Group 19 number 17-89, dated July 14, 2017.

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Source: NHTSA ID: 10199717