2025-2026 Audi A5/S5 AC Button Deactivates TSB 2080019/2

Audi has released Technical Service Bulletin (TSB) 2080019/2 to address a specific air conditioning system malfunction affecting certain 2025-2026 Audi A5 and S5 models. This bulletin outlines a condition where the AC button automatically deactivates itself shortly after being pressed, leading to a non-functional air conditioning system. This issue is primarily attributed to a software fault within the vehicle's thermal management system.

This TSB is particularly relevant for owners of the specified models equipped with PR: 0K0 (without alternative drive system). If you experience the Audi A5 S5 AC button deactivates issue, understanding this bulletin can help you communicate effectively with your service center.

Symptoms of AC Malfunction

Owners of affected Audi A5 and S5 vehicles may notice that their air conditioning system is not working as expected. The primary symptom is that the AC button, located on the climate control panel, will automatically deactivate itself almost immediately after the driver attempts to turn it on. This prevents the air conditioning from engaging and cooling the cabin.

Diagnostic Trouble Code (DTC) and Fault Label

When this issue occurs, a specific diagnostic trouble code (DTC) is typically logged in the vehicle's diagnostic system. Workshop findings indicate that the event memory entry "B16A1F0 - Refrigerant Shut-Off Valve, icing - water load too high" is recorded. This fault code is found in diagnostic address 00C5, which pertains to the thermal management control unit. The presence of this specific code confirms the software-related nature of the problem.

Understanding the Root Cause

The technical background provided in TSB 2080019/2 clarifies that the Audi A5 S5 AC button deactivates problem stems from a software issue. This software anomaly is located within the diagnostic address 00C5, which manages the vehicle's thermal systems. Essentially, the control unit incorrectly detects a condition related to the refrigerant shut-off valve, leading it to prematurely deactivate the AC system to prevent perceived icing or excessive water load.

The Repair: Software Update

The resolution for this air conditioning system malfunction is a software update. Technical Service Bulletin 2080019/2 indicates that it replaces a previous Pending Service Solution (PSS) TSB, number 2079225, which addressed the same issue. The actual software update procedure is detailed in TSB 2079690, specifically for software version 03.10.00/C (28.13.01) KD2. This update is designed to correct the software logic within the thermal management control unit, preventing the erroneous deactivation of the AC system.

During the software update process, technicians will need to connect a battery charger to ensure stable voltage throughout the flashing procedure. The update involves specific labor operations, including preliminary and follow-up work to ensure proper system integration. This ensures that the vehicle's electrical system remains stable and prevents potential issues during the software installation.

Dealer Service and Warranty Information

Owners experiencing the Audi A5 S5 AC button deactivates issue should take their vehicle to an authorized Audi service center. The service center will perform the necessary diagnostic checks and apply the software update as outlined in TSB 2080019/2 and its referenced bulletin 2079690. The service number associated with this repair is 8711, and the damage code is KD02.

Labor operations for this repair include:

• 0151 0010: Software update, including connecting a battery charger.
• 0151 0040: Fixed rate for the software update, encompassing all required preliminary and follow-up work, such as bus sleep cycle, calibration drive, and additional tasks (130 time units).
• 0150 9999: An additional lump sum of 50 time units may be applied for each documented attempt in case of additional attempts or flash cancellations.

Important Warnings for Owners

It is crucial for owners to understand the warranty implications of this Technical Service Bulletin. If your vehicle is outside of its applicable warranty period, this TSB serves as informational guidance only. In such cases, the cost of the diagnostic work and the software update may not be covered by Audi. Owners should always confirm their warranty status with their Audi dealer prior to any service.

Revision History of TSB 2080019/2

This Technical Service Bulletin has undergone revisions since its initial publication. Revision 1 was published on November 13, 2025. Revision 2, dated December 17, 2025, included updates to the header to add model years and revised warranty information, specifically updating labor operations. This ensures the bulletin remains current and accurate for technicians.

Production Integration

Audi has implemented a production solution for the A5 model line, with the fix being integrated into new vehicles starting from week 10 of 2025. This means that vehicles produced after this date should already have the updated software and not exhibit the AC deactivation issue.

Source: NHTSA ID 11027396