2021-2023 Nissan Horn Inoperative TSB NTB22-051B

Symptoms

Owners of affected Nissan vehicles may experience a completely inoperative horn. This means that when the horn pad is pressed, no sound is produced, indicating a failure in the horn system.

Diagnosis and Trigger Conditions

Technicians will diagnose the Nissan horn inoperative condition by inspecting the horn pad for a pinched ground wire. This wire, if compressed or damaged, can prevent the horn from functioning correctly. Some 2023 models include a rigid plastic wire guide designed to prevent pinching, but even with this guide, the wire can still become pinched if the guide is bent out of position.

Repair Procedure Summary

The repair for a Nissan horn inoperative issue involves several steps, primarily focusing on safely accessing and replacing the horn components:

1. Preparation: Before starting, the technician will record the vehicle's radio settings. The negative battery terminal is then disconnected, and protective tape is applied. A minimum 3-minute wait period is observed to allow the airbag diagnosis unit to discharge, preventing accidental airbag deployment.
2. Airbag Module Removal: Using a special Airbag Release Tool (J-52551 / NI-52551), the driver airbag module is carefully disengaged and removed from the steering wheel. This involves locating and manipulating access holes on the back and bottom of the steering wheel to release retaining springs.
3. Ground Wire Inspection: Once the airbag module is removed, the horn ground wire is inspected for any signs of pinching. If a pinched wire is found, the repair proceeds to horn replacement.
4. Horn Replacement: The high and low horns are replaced. The specific part numbers for these horns (25610-***** for high, 25620-***** for low) are determined using the vehicle's VIN in the Electronic Parts Catalog (EPC).
5. Airbag Module Reinstallation: The driver airbag module is reinstalled in reverse order. Crucially, if the vehicle does not have a wire guide, the module is rotated 360 degrees clockwise during installation to remove slack and prevent the ground wire from re-pinching. If a wire guide is present, the module is installed without rotation, ensuring the connector has adequate retention and the guide is properly positioned.
6. Final Steps: The negative battery terminal is reconnected. Additional service procedures related to 12V battery disconnection are performed. Finally, the technician tests the horns to confirm they operate correctly.

Required Tools or Parts

To address the Nissan horn inoperative condition, specific tools and parts are necessary:

• Special Tool: Airbag Release Tool – J-52551 (new part number: NI-52551). This tool is essential for safely removing the airbag module.
• Parts:
  • HORN ASSY – ELECTRIC HIGH (Part Number: 25610-*****)
  • HORN ASSY – ELECTRIC LOW (Part Number: 25620-*****)
  • The exact part numbers for the horns must be determined using the vehicle's VIN.

Important Warnings

Nissan emphasizes several critical points for technicians and owners:

• Professional Service: This bulletin is intended for use by qualified technicians, not 'do-it-yourselfers'. Technicians are properly trained and equipped to perform this repair safely.
• Battery Disconnection Safety: After disconnecting the negative battery terminal, a minimum of 3 minutes must pass before proceeding to ensure the airbag diagnosis unit fully discharges. During this time, do not operate the vehicle (e.g., locking/unlocking doors) to prevent damage to the ACC power supply.
• Airbag Safety: Verify the ignition switch is OFF and the 3-minute waiting period has elapsed before working on the airbag module to prevent personal injury or vehicle damage.
• Wire Repair Not Needed: If a pinched ground wire is found, it does not require a separate wire repair; the solution is to replace the high and low horns.

Owner Action

If you experience a Nissan horn inoperative condition, it is recommended to schedule an appointment with your authorized Nissan dealer. The repair involves working with the airbag system and requires specialized tools and training. The dealer will diagnose the issue, confirm if it's related to a pinched ground wire, and perform the necessary horn replacement. This service is covered under warranty if your vehicle meets the eligibility criteria.

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NHTSA ID: 10240538