2021-2026 Audi Door Lock Faults B122D29, B14FF29, B122B13

Owners of certain 2021-2026 Audi vehicles may encounter issues with their vehicle's door locks, leading to difficulty opening doors or triggering warning messages. Audi Technical Service Bulletin (TSB) 2063236/9 has been released to provide technicians with a comprehensive guide for diagnosing and resolving these door lock complaints, specifically addressing diagnostic trouble codes (DTCs) B122D29, B14FF29, and B122B13.

Symptoms

Owners may notice several symptoms indicating a door lock malfunction. These can include:

• Front or rear doors that cannot be opened from either the outside or the inside.
• Warning messages appearing on the dashboard, such as those related to the exit warning system or central locking.
• The vehicle remaining locked, even if a door can still be opened using a physical key.
• General unresponsiveness or failure of the door locks to operate as expected.

Fault Codes / DTCs

When a door lock issue occurs, specific diagnostic trouble codes (DTCs) may be stored in the vehicle's control units. TSB 2063236/9 highlights the following relevant codes:

Code	Description	Module
B122D29	Lock unit for central locking implausible signal	Driver's door electronics, Passenger's door electronics, Rear drivers side door electronics, Rear passenger side door electronics
B14FF29	Motor for child safety lock implausible signal	Rear drivers side door electronics, Rear passenger side door electronics, Driver's door electronics
B122B13	Central locking motors Open circuit	Driver's door electronics, Passenger's door electronics

These codes point to specific electrical or mechanical failures within the door lock assembly or its control system. For example, an Audi door lock fault B122D29 indicates that the central locking unit is sending an implausible signal, suggesting an internal fault or communication error.

Diagnosis / Trigger Conditions

Before any parts replacement, technicians are instructed to perform several diagnostic steps. These include:

• Customer Interview: Clarifying if the interior door handle was pulled too quickly or past its end stop, or if the door opens after pulling the interior handle twice or using the exterior handle.
• Event Memory Check: Reading and erasing any stored event memory entries in the control unit. After cycling the ignition and operating the door, the system is re-checked for recurring fault codes.
• Mechanical Inspection: A thorough check of the electrical wiring and mechanical Bowden cables connected to the door lock and handles for any damage, irregularities (e.g., twisting, stiffness), or signs of water/ice.
• Exterior Handle Function: Verifying that the exterior door handle returns to its flush, original position after being operated. If not, a separate TSB (2060196) regarding exterior door handles not returning to the zero position may apply.
• Door Setting: Checking the door's overall setting for ease of movement and proper closing, and adjusting if necessary.

Repair Procedure Summary

Audi's TSB 2063236/9 outlines a structured approach for addressing door lock complaints. The repair process emphasizes thorough diagnosis before part replacement:

1. Initial Assessment: Technicians are advised to first rule out incorrect customer operation of the door handles, as this can sometimes mimic a fault. Reference to the Owner's Manual may be used to explain proper door lock function.
2. Event Memory Management: The vehicle's event memory should be read and cleared. Following this, the ignition is cycled, the door is opened and closed, and the system is re-checked to see if the fault codes, such as an Audi door lock fault B122D29, reappear.
3. Mechanical and Electrical Inspection: A detailed inspection of the electrical wiring and mechanical Bowden cables at the door lock and interior/exterior door handles is crucial. Technicians look for any damage, irregularities, twisting, incorrect routing, or stiffness. Any affected components should be replaced.
4. Exterior Door Handle Check: The exterior door handle's ability to return to its flush, original position must be verified. If it does not, technicians are directed to consult TSB 2060196 for further guidance or replacement.
5. Door Adjustment: The door's setting should be checked for ease of movement and correct closing, with adjustments made as needed.
6. Guided Fault Finding: If the complaint persists or event memory entries are still logged after these checks, technicians are instructed to proceed with the Guided Fault Finding system for further diagnosis.

Owner Action

If you are experiencing door lock problems in your 2021-2026 Audi, particularly if you've seen warning messages or the door is difficult to open, it is recommended to contact an authorized Audi service center. They have access to the specific diagnostic tools and procedures outlined in TSB 2063236/9 to accurately diagnose and repair the issue. Warranty coverage for repairs related to an Audi door lock fault B122D29 or other associated DTCs will depend on your vehicle's specific warranty status.

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Source: NHTSA ID: 11018965