2021 Nissan Sentra P161D Immobilizer Fault TSB

Symptoms

Owners of a 2021 Nissan Sentra may find the diagnostic trouble code (DTC) P161D, related to the immobilizer system, stored in the Body Control Module (BCM). The technical service bulletin (TSB) does not specify any direct owner-facing symptoms such as warning lights or vehicle starting issues, but rather focuses on the presence of this specific fault code within the vehicle's system.

Fault Codes / DTCs

The primary fault code addressed by this bulletin is:

• P161D: Immobilizer

If any other diagnostic trouble codes are present in the BCM alongside the Nissan Sentra P161D code, technicians are instructed to diagnose and resolve those additional DTCs first before proceeding with the BCM reprogramming outlined in this bulletin.

Diagnosis / Trigger Conditions

To confirm if this TSB applies to a 2021 Nissan Sentra, a technician must verify the following conditions:

• The DTC P161D (Immobilizer) is stored in the Body Control Module (BCM).
• No other DTCs are present in the BCM. If other codes exist, they must be addressed first.
• The current ECU PART NUMBER in the BCM is either 284B3-3613R (for 2020 model year vehicles, though the NHTSA data for this bulletin specifically lists 2021 models) or 284B3-6580R (for 2021 model year vehicles). If the ECU PART NUMBER is 284B3-3370R, this bulletin does not apply.

Important Warnings

This technical service bulletin includes several critical warnings and precautions for technicians to ensure a successful repair and prevent damage to vehicle components:

• Battery Voltage: A battery maintainer or smart charger must be connected and set to reflash mode. The vehicle's battery voltage must remain between 12.0V and 15.5V during the reprogramming process. If the voltage drops below 12.0V or rises above 15.5V, the BCM may be damaged.
• Electrical Loads and Bluetooth Devices: All vehicle electrical loads must be turned OFF. Additionally, all external Bluetooth® devices (e.g., cell phones, printers) within range of the CONSULT PC and Vehicle Interface (VI) must be turned OFF to prevent signal interference that could interrupt reprogramming.
• CONSULT PC Power: The AC adapter must be connected to the CONSULT PC. If the PC's battery voltage drops during reprogramming, the BCM may be damaged.
• Expected Errors: Technicians are advised that some errors are expected to appear during the reprogramming process. These are normal, and the procedure must be followed completely to successfully finish the repair.
• Do Not Disconnect: Technicians must not disconnect the VI or shut down CONSULT if reprogramming does not complete, as this can lead to further issues.
• BCM Battery Saver Mode: Approximately 90 seconds after the reprogramming is complete, the BCM will enter battery saver mode, and the ignition will turn OFF. Technicians must periodically check and turn the ignition ON as needed during the configuration phase.
• Configuration Settings Documentation: The SAVE function for configuration settings will NOT work during this reprogram. Technicians MUST document or print all configuration settings manually, as these will be needed later in the procedure.
• Bulletin Applicability: The bulletin is not applicable if "DTC_P161D_CM" is not listed as an available reprogram option.

Repair Procedure Summary

Addressing the Nissan Sentra P161D immobilizer fault involves a multi-step reprogramming and configuration procedure for the Body Control Module (BCM) using the Nissan CONSULT diagnostic system. The process is extensive and requires careful attention to detail:

1. Initial Setup: Connect the CONSULT PC to Wi-Fi, ensure ASIST and C-III plus software are updated, and connect the Vehicle Interface (VI) to the vehicle. Log in using NNAnet credentials.
2. Vehicle Identification: Select "Diagnosis (All Systems)" and confirm the vehicle's VIN or Chassis number.
3. DTC Verification and Erasing: Confirm that only the P161D DTC is present. If other DTCs exist, they must be resolved first. Erase all DTCs before proceeding.
4. BCM Selection and ECU Part Number Confirmation: Select the BCM module within the CONSULT system. Verify that the BCM's ECU PART NUMBER is either 284B3-3613R or 284B3-6580R. If it's 284B3-3370R, the bulletin does not apply.
5. Documenting BCM Configuration Settings: This is a crucial step. Navigate to "Before ECU Replacement" under "VEHICLE CONFIGURATION" and manually record or print all current BCM configuration settings, as the save function will not work.
6. BCM Reprogramming: Select "Reprogramming" and follow the on-screen instructions. If the system displays "Error Code “Reprogramming Ignition off Error”" and the ignition turns OFF, turn the ignition ON (engine OFF) and select "Retry". If "Reprogramming Not Needed" is displayed, the reprogramming is complete.
7. BCM Configuration: After reprogramming, the BCM will enter battery saver mode. Select "Other Operation", then "After ECU Replacement" under "VEHICLE CONFIGURATION". Use the manually documented settings to configure the BCM via "Manual selection" and write the configuration to the BCM.
8. TPMS Sensor Registration: Register the Tire Pressure Monitoring System (TPMS) sensors by referring to the Electronic Service Manual (ESM) section: SUSPENSION > ROAD WHEELS & TIRES > BASIC INSPECTION > ID REGISTRATION PROCEDURE.
9. Final DTC Erasing: Select "Diagnosis (All Systems)" again, confirm the VIN, and erase any remaining DTCs.
10. Completion: Close the C-III plus application and remove the VI from the vehicle.

Required Tools or Parts

Technicians will require specific tools to perform this service bulletin:

• CONSULT PC: A diagnostic computer with the ASIST application and C-III plus software, fully updated.
• Vehicle Interface (VI): To connect the CONSULT PC to the vehicle.
• Battery Maintainer/Smart Charger: Essential for maintaining stable battery voltage during reprogramming.
• AC Adapter: For the CONSULT PC to prevent power loss.

Owner Action

If you own a 2021 Nissan Sentra and suspect an immobilizer fault or have had a diagnostic scan reveal the Nissan Sentra P161D code, it is recommended to contact your authorized Nissan dealer. This technical service bulletin outlines a complex reprogramming procedure that requires specialized diagnostic tools and trained technicians. The repair involves reprogramming the Body Control Module (BCM), and the associated claims information for dealers uses an operation code RXC4AA with a labor time of 0.9 hours.

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Source: NHTSA ID: 10226064