2021 Nissan Sentra False AEB/FCW Activation TSB

Symptoms

Owners of 2021 Nissan Sentra vehicles may experience a Nissan Sentra false AEB activation or unexpected braking. This can occur with both the Automatic Emergency Braking (AEB) and Forward Collision Warning (FCW) systems.

The primary symptom is the system engaging or warning without an actual obstacle or imminent collision, leading to unexpected deceleration or braking of the vehicle.

Fault Codes / DTCs

Nissan Technical Service Bulletin NTB21-115A specifies that there are no related DTCs stored in the vehicle's system when this false activation occurs. This means that traditional diagnostic trouble codes will not be present to indicate the issue.

Important Warnings for Owners

Nissan has issued several important warnings related to this bulletin and the repair procedure:

• "Nissan Bulletins are intended for use by qualified technicians, not 'do-it-yourselfers'."
• "If you believe that a described condition may apply to a particular vehicle, DO NOT assume that it does. See your Nissan dealer to determine if this applies to your vehicle."
• During the reprogramming process, if the vehicle battery voltage drops below 12.0V or rises above 13.5V, the ICC/ADAS 2 control module may be damaged.
• All vehicle electrical loads must be turned OFF during reprogramming. If a load remains ON, the ICC/ADAS 2 control module may be damaged.
• If the CONSULT PC battery voltage drops during reprogramming, the process will be interrupted, and the ICC/ADAS 2 control module may be damaged.
• All external Bluetooth® devices (e.g., cell phones, printers) must be turned OFF and kept out of range of the CONSULT PC and Vehicle Interface (VI) during reprogramming. Bluetooth® signal interference can interrupt the process and damage the ICC/ADAS 2 control module.
• "Do not disconnect the VI or shut down CONSULT if reprogramming does not complete."
• The bulletin states: "FRT allows adequate time to access DTC codes. No other diagnostic procedures subsequently required. Do NOT claim any Diagnostic Op Codes with this claim."

Repair Procedure Summary

The resolution for the Nissan Sentra false AEB activation involves reprogramming the Intelligent Cruise Control / Advanced Driver Assistance Systems (ICC/ADAS 2) control module. This procedure must be performed by a qualified Nissan technician using the CONSULT-III plus diagnostic tool.

The general steps include:

1. Confirmation: The technician first confirms the current part number of the ICC/ADAS 2 module.
2. Preparation: The vehicle's ignition is turned ON (engine OFF), hazard lights are activated, and a battery maintainer is connected to ensure stable voltage (between 12.0V and 13.5V) throughout the process. All electrical loads and external Bluetooth devices are turned off.
3. Reprogramming: Using the CONSULT-III plus software, the technician selects the appropriate reprogramming option for the ICC/ADAS 2 module. This involves confirming the vehicle's VIN and ensuring the correct software is selected.
4. Data Transfer & Verification: The new software is transferred to the ICC/ADAS 2 module. The technician verifies that the part numbers before and after reprogramming are different, indicating a successful update.
5. DTC Erase: Any existing Diagnostic Trouble Codes are erased from the system.
6. Configuration: The module is configured with the correct Type ID, which is determined by referring to the electronic parts catalog.
7. Final Check: A final check is performed to ensure all functions are operating correctly.

Required Tools or Parts

Technicians will use the Nissan CONSULT-III plus diagnostic system, including a Vehicle Interface (VI), and a battery maintainer or smart charger. The ICC/ADAS 2 control module is the component being updated.

Applicable ICC/ADAS 2 Part Numbers (P/N) that may require this update include those starting with 284P1- and ending with:

• 6LA1E
• 6LA3A, 6LA4A, 6LA5A, 6LA6A, 6LA7A, 6LA7E
• 6LW0A, 6LW0B, 6LW0C, 6LW0D, 6LW0E
• 6LW1A, 6LW1B

During the configuration process, a Type ID in the format of 284P4-XXXXX is used.

Owner Action

If your 2021 Nissan Sentra is experiencing false activation of the Automatic Emergency Braking (AEB) or Forward Collision Warning (FCW) systems, you should contact your authorized Nissan dealer. They will be able to diagnose the issue and perform the necessary software update to the ICC/ADAS 2 control module as described in Technical Service Bulletin NTB21-115A.

Amendment History

This bulletin, NTB21-115A, is an amendment to the original bulletin NTB21-115, which was published on December 17, 2021. The May 10, 2024, revision (NTB21-115A) added specific applied dates for vehicles built on or before March 10, 2022, updated login steps for the diagnostic tool, and clarified battery voltage ranges on pages 2, 10, and 13 of the procedure.

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Source: NHTSA ID 11004970