2021 Nissan Sentra High Frequency Audio Noise TSB

Owners of certain 2021 Nissan Sentra models may notice a high frequency noise emanating from the audio system when the display screen is turned on. This issue, identified as a 17 kHz noise, is the subject of Nissan Technical Service Bulletin NTB21-067B. This bulletin provides a solution involving an infotainment software update to resolve the audible disturbance.

Symptoms of High Frequency Noise

The primary symptom is a high frequency (17 kHz) noise that occurs specifically when the audio system display screen is turned ON. It's important to note that this noise may not be audible to all individuals, as the 17 kHz range can be difficult for some people to hear. The noise can be present whether the audio system itself is playing or turned OFF, as long as the display screen is active. Crucially, if the audio system display screen is turned OFF, the high frequency noise should not be heard. This specific condition helps in diagnosing the Nissan Sentra high frequency noise issue.

Diagnosis and Trigger Conditions

To determine if your 2021 Nissan Sentra is affected by this Nissan Sentra high frequency noise, a technician will first confirm the current software version of the Audio Control Unit. The bulletin specifies that vehicles with software versions 321 or 420 are candidates for this update.

Additionally, technicians must check the Service Comm system. If Service Comm indicates that campaign PM991 applies to your vehicle, then that campaign should be performed instead, and this bulletin (NTB21-067B) should not be applied. This distinction is critical to ensure the correct repair procedure is followed for your vehicle.

Repair Procedure Summary

The resolution for the high frequency noise involves updating the infotainment software in the vehicle. After confirming the Audio Control Unit software version, a Nissan technician will proceed with the software update.

The detailed instructions for this update are found within the "Infotainment Software Update Utility." This utility is accessible to technicians through ASIST, under the SPECIALTY TOOLS section, specifically within "Infotainment Software Updates." The utility provides the latest update software, detailed procedures for the infotainment update, and information necessary for processing warranty claims related to this repair.

Important Warnings for Owners and Technicians

Nissan emphasizes that the purpose of the action outlined in the bulletin is to provide a quick overview of the necessary work. It is critical that technicians closely follow the comprehensive procedures provided in the "Infotainment Software Update Utility." This utility contains essential information required to successfully complete the repair and should not be bypassed or summarized.

Owners should also be aware of the Service Comm check for PM991. If your dealer indicates that PM991 applies to your vehicle, ensure that the appropriate procedure for PM991 is followed, as this bulletin (NTB21-067B) would not be the correct solution in that specific scenario.

Owner Action

If you own a 2021 Nissan Sentra SR or SV model and are experiencing a high frequency noise when your audio system display is on, it is recommended to contact your authorized Nissan dealer. Explain the symptoms you are experiencing, specifically mentioning the 17 kHz noise and its correlation with the display screen being on. The dealer will be able to diagnose the issue, check your vehicle's current Audio Control Unit software version, and perform the necessary infotainment software update as outlined in Nissan Technical Service Bulletin NTB21-067B.

Bulletin History

This bulletin, NTB21-067B, is the latest revision addressing this issue. It supersedes previous versions:

• NTB21-067: Original bulletin published on July 29, 2021.
• NTB21-067A: Published on March 23, 2023, with various changes throughout.
• NTB21-067B: Published on January 29, 2024, specifically revised to reference the "Infotainment Software Update Utility" in ASIST, replacing a previous reference to NTB23-018.

Source: NHTSA ID 10249905