2021-2023 Audi Seat Belt or Pre Sense Warning TSB

Symptoms

Owners of 2021-2023 Audi vehicles may experience the following symptoms related to this issue:

• A "Seat belt warning" message appearing sporadically in the driver information system (DIS) while driving.
• A "Pre Sense warning" message appearing sporadically in the DIS while driving.

These warnings typically indicate that the vehicle's safety computer is detecting an unusual state with the driver's seat belt.

Fault Codes / DTCs

When these symptoms occur, the following Diagnostic Trouble Code (DTC) may be stored in the airbag control module/safety computer (J234):

Code	Description	Module
B101C07	Driver seat belt switch mechanical malfunction	Airbag control module/safety computer

Diagnosis / Trigger Conditions

Audi's Safety Computer continuously monitors the status of the seat belt latch switch (E24). The system expects to see changes in the switch signal as the seat belt is buckled and unbuckled. If a seat belt extender, a seat belt cheat device, or a continuously buckled seat belt is used, the Safety Computer receives a constant signal that the seat belt is always latched.

If the Safety Computer does not detect a change in the belt latch switch signal within five consecutive drive cycles, it will store DTC B101C07. This also causes the "Pre Sense Warning" to appear in the DIS, as the system assumes a seat belt cheat device is installed. A drive cycle consists of a specific sequence of actions:

1. Unlock the door.
2. Open the door.
3. Close the door.
4. Latch the seat belt.
5. Turn on the ignition and drive.
6. Park.
7. Unlatch the seat belt.
8. Turn off the ignition.
9. Open the door.
10. Close the door.
11. Lock the door.

Important Warnings

Warning: The risk of serious or fatal injury increases if the seat belt is not fastened, if it is worn incorrectly, or if it is damaged. Always refer to your owner's manual for additional safety information and warnings.

Note: Parts replacement does not solve this issue. Audi states that claims for replaced parts will be subject to review, indicating that replacing the seat belt latch switch or related components is unlikely to resolve the underlying cause if a cheat device is in use.

Repair Procedure Summary

If the DTC B101C07 is stored in the airbag control module/safety computer, technicians should follow all applicable Guided Fault Finding (GFF) test plans using the ODIS Service system. If the GFF diagnostic process indicates that the seat belt latch switch is not defective, the customer should be informed that the use of a seat belt extender, seat belt cheat device, or continuously buckled seat belt could be the cause of the concern.

To clear the DTC B101C07 and turn off the Pre Sense warning in the instrument cluster, a single drive cycle that includes latching and unlatching the seat belt is sufficient. This TSB, identified as 69 23 94 2056421/7, supersedes previous bulletin 21-75 and was last revised on July 21, 2023.

What Owners Should Do

If you experience an Audi e-tron seat belt warning or Pre Sense warning along with DTC B101C07, it is recommended to have your vehicle diagnosed by an authorized Audi service facility. Ensure that you are not using any seat belt extenders or cheat devices, as these are the primary cause of this specific issue. Discuss your driving habits and any accessories with your technician to help them accurately diagnose the problem. This TSB is informational only and is not applicable to any Audi Warranty.

Source: NHTSA ID: 10239688