2021-2024 Audi Key Not Recognized / Immobilizer Servicing TSB

Symptoms of Key Reader Malfunction

Owners of various Audi models, including the 2021-2024 Audi Q5, SQ5, A3, S3, RS 3, e-tron GT, and RS e-tron GT, may encounter a frustrating problem: their vehicle does not start when the key is placed on the designated reader coil. This symptom directly points to a failure in the key recognition process. Beyond starting issues, this malfunction can also impact critical service procedures. Technicians might find themselves unable to adapt the vehicle key or the immobilizer system, which is a necessary step for certain repairs or replacements. When this occurs, a specific diagnostic message will appear, informing both the owner and technician of the problem.

Diagnostic Message: "FAZ1552 – Key status invalid"

The primary indicator for this specific issue is the diagnostic message "FAZ1552 – Key status invalid". This message is displayed during the adaptation procedure of the vehicle key or immobilizer, or it may appear on the instrument cluster. It signifies that the vehicle's immobilizer system, a crucial anti-theft component, is not receiving valid data from the key, preventing the engine from starting. This specific fault label is key for identifying the problem described in Audi Technical Service Bulletin 57 23 05 2070128/1.

Technical Background of the Issue

Audi Technical Service Bulletin 57 23 05 2070128/1 explains that the root cause of the 2021-2024 Audi key not recognized problem is surprisingly simple: an incorrectly positioned lining mat in the cup holder. This mat features a symbol indicating the precise location for the key reader coil. If this mat is inserted the wrong way around—perhaps after being removed for cleaning—the pictogram will be misaligned. This misalignment leads to owners or technicians placing the key in an incorrect spot relative to the hidden reader coil. As a result, the key cannot be properly scanned, leading to the "FAZ1552 – Key status invalid" message and preventing the vehicle from starting or the immobilizer from being serviced.

Repair Procedure Summary

The solution to this key recognition problem is straightforward and does not require complex parts replacement or software updates. The repair involves simply moving the lining mat in the cup holder to its correct orientation.

For Audi Q5 models, the pictogram for the reader coil must be positioned in the front left cup holder, facing forward in the direction of travel. Similarly, for the Audi e-tron GT, the pictogram needs to be in the forward front cup holder, specifically on the right side. In Audi A3 models, the pictogram for the reader coil should also be in the forward front cup holder. Ensuring this small mat is correctly placed allows the key reader coil to function as intended, resolving the 2023 Audi S3 key not recognized issue and allowing the vehicle to start normally.

Important Warnings for Owners

It is important for owners to note that this Technical Service Bulletin (TSB 57 23 05 2070128/1) is provided for informational purposes only. This means that the resolution for this particular issue is generally not covered under any standard Audi warranty. Owners experiencing the "FAZ1552 – Key status invalid" message should be aware that while the fix is simple, it may not be a warrantable repair. Always consult with your authorized Audi service center for specific details regarding your vehicle and potential costs.

Source: NHTSA ID: 10235475, TSB 57 23 05 2070128/1