2025 Audi S3 'Vehicle Electronics: Fault' TSB 2076134/3

Symptoms

Owners of certain 2025 Audi S3 and A3 models may observe an intermittent message in the instrument cluster stating: "Vehicle electronics: fault. Shift to P before leaving vehicle. Please contact workshop". This message typically appears without any other yellow or red warning lights and without any noticeable functional issues with the vehicle.

Fault Codes / DTCs

When the "Vehicle electronics: fault. Shift to P before leaving vehicle. Please contact workshop" message appears, the following Diagnostic Trouble Codes (DTCs) may be stored in the vehicle's control units:

• U112300: Data bus error value received (stored in diagnostic address 0009, the onboard supply control unit). This DTC can be static or intermittent.
• B101C07: Driver seat belt switch mechanical malfunction (stored in diagnostic address 0015, the airbag control unit). This DTC is specifically logged when the seat belt is permanently fastened across multiple driving cycles.

The TSB also references an internal symptom code, 8667429, associated with the U112300 DTC. Another diagnostic identifier mentioned is IDE12257 for "Extended belt switch diagnostic" in the airbag control unit.

Diagnosis and Trigger Conditions

The appearance of the "Vehicle electronics: fault. Shift to P before leaving vehicle. Please contact workshop" message is linked to Audi's "leaving concept," a safety feature designed to prevent roll-away by monitoring driver presence, including the seat belt buckle status. The system evaluates the last five driving cycles, defined by specific events like unlocking, door opening/closing, ignition on/off, and exceeding 10 km/h.

The 2025 Audi S3 electronics fault system triggers the message if the seat belt buckle status (fastened or unfastened) remains unchanged across several consecutive driving cycles. This can occur if the driver consistently uses a permanently fastened seat belt (e.g., with a dummy clip) or if the seat belt is permanently unfastened (e.g., during maneuvering). The vehicle's system interprets this lack of change as an implausible condition, leading to the warning message and the storage of DTC U112300. If the seat belt is permanently fastened, DTC B101C07 will also be stored.

The driving cycle counter can be monitored using the measured value "Extended belt switch diagnostic IDE12257" in the airbag control unit (diagnostic address 0015). If the seat belt is correctly fastened or unfastened, this counter will decrease by two. Erasing the event memory entry for U112300 in the onboard supply control unit (diagnostic address 0009) will reset the counter to zero.

Important Warnings for Owners

Audi Technical Service Bulletin 2076134/3 clarifies that this condition is not considered a fault. Therefore, it is not covered under warranty, and it is not possible to bill for fault finding or component replacement through warranty claims.

Owners should be aware that if no other instrument cluster messages (yellow/red) or functional issues are present, the vehicle is operating as designed.

Owner Action

If you experience the "Vehicle electronics: fault. Shift to P before leaving vehicle. Please contact workshop" message in your 2025 Audi S3 electronics fault system, and there are no other warning lights or functional problems, your Audi dealership will inform you about the vehicle's seat belt buckle monitoring function. You will be advised not to drive the vehicle with the seat belt permanently fastened or permanently unfastened across several driving cycles. This TSB (2076134/3) indicates that the message is a result of the system's intended operation under specific conditions related to seat belt usage patterns.

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Source: NHTSA ID: 11016534