2021-2024 Nissan Sentra Remote Engine Start Inoperative TSB

Nissan Technical Service Bulletin (TSB) NTB20-055A addresses a specific issue affecting the 2021-2024 Nissan Sentra. This bulletin, which supersedes the original NTB20-055, provides critical information for technicians replacing the Body Control Module (BCM) service part.

The TSB highlights that improper procedure during BCM replacement can lead to the permanent disabling of key vehicle functions, including the popular Nissan Sentra remote start feature and the A/T shift lock.

Symptoms

Owners of affected 2021-2024 Nissan Sentra vehicles may notice two primary symptoms after a BCM service part replacement:

• A/T Shift Lock Inoperative: The automatic transmission shift lock mechanism may no longer function as intended.
• Remote Engine Start Inoperative: The "Nissan Sentra remote start" function, also known as Remote Engine Start (RES), will not work. The system's default setting for Remote Engine Start is "WITHOUT" if not configured correctly.

These issues arise specifically after a new BCM has been installed but before its proper configuration.

Diagnosis and Trigger Conditions

The root cause of these inoperative features is directly related to the sequence of operations performed after installing a new BCM service part. If the Intelligent Key UNLOCK button is pressed before the BCM configuration procedure is completed using the CONSULT-III plus diagnostic tool, certain BCM parameters will become permanently locked in their default settings.

Crucially, the Remote Engine Start (RES) parameter is one of those affected. Once locked in the default "WITHOUT" setting due to premature Intelligent Key use, the RES function becomes permanently disabled. This highlights the importance of following the precise configuration steps outlined in the TSB.

Important Warnings for Technicians and Owners

Nissan has issued several explicit warnings to prevent this permanent disabling of features:

• "The RES function WILL BE permanently disabled if the UNLOCK button is pressed BEFORE the BCM service part is configured."
• "To avoid permanently disabling the RES feature after replacing the BCM, the configuration procedure must be performed first so that all of the vehicle features operate correctly."
• "Avoid pressing the UNLOCK button on the Intelligent Key after a BCM replacement. Wait until the configuration process has completed and the default configuration has been overwritten with the correct data before pressing any Intelligent Key buttons."
• "Never press the UNLOCK button on the Intelligent Key until the configuration settings step has been completed."

These warnings emphasize that the timing of BCM configuration is critical. Failure to adhere to these instructions will result in the permanent loss of the Nissan Sentra remote start and A/T shift lock functionality, requiring further diagnosis and potential part replacement to rectify.

Repair Procedure Summary

The resolution for this issue involves a specific sequence of steps during BCM replacement and configuration. The primary goal is to ensure the BCM is fully configured before any Intelligent Key functions are used.

1. Install New BCM: Replace the Body Control Module service part as necessary.
2. Perform BCM Configuration: Immediately after installation, perform the BCM configuration procedure using the CONSULT-III plus diagnostic tool. This configuration can be done manually or by downloading saved configuration data from the previous BCM, if available.
3. Avoid Intelligent Key Use: It is critical to avoid pressing the UNLOCK button on the Intelligent Key or any other Intelligent Key buttons until the BCM configuration process is entirely complete and the default settings have been overwritten with the correct vehicle data.

It is important to note that registering Intelligent Keys to a new BCM is not necessary. The focus is solely on the BCM's internal configuration parameters.

Required Tools or Parts

To properly configure the BCM and prevent the permanent disabling of features, the CONSULT-III plus diagnostic tool is required. This specialized tool allows technicians to access and modify the BCM's configuration parameters.

Owner Action

If you own a 2021-2024 Nissan Sentra and are having a BCM replaced, or if you've recently had a BCM replaced and your Nissan Sentra remote start or A/T shift lock is no longer working, it is important to discuss this Technical Service Bulletin NTB20-055A with your Nissan dealer. Ensure that the technicians are aware of and follow the precise configuration procedure to prevent or rectify the permanent disabling of these features. If the issue has already occurred, your dealer will need to diagnose the BCM's configuration status.

Source: NHTSA ID 11004965