B2CE655 - B2CE655 Offline NVM No Configuration Information

Fault Code Deep Definition

The fault code B2CE655 is defined as "Line Non-Volatile Memory (NVM) No Configuration Information". This code represents a key status identifier within the chassis domain controller and Advanced Driver Assistance Systems (ADAS) diagnostic logic. In the overall vehicle manufacturing process, "Line NVM" carries critical vehicle feature codes, function switch states, and radar hardware calibration data written by the factory.

This fault code indicates that the control unit failed to read necessary configuration information during the self-check phase. In the Adaptive Cruise Control (ACC) architecture, the front millimeter-wave radar serves as a core sensing component, relying on function enable/disable bits stored in NVM for its operating modes. When the control unit detects missing memory data or verification failure, it determines "No Configuration Information". This fault code is directly related to the vehicle initialization process in the overall electronic electrical architecture, affecting the on-board system's correct identification and activation of hardware functions, belonging to the technical category of system-level configuration validation failure.

Common Fault Symptoms

When the storage controller records B2CE655 fault code, the vehicle owner may observe the following dashboard feedback and functional behavior during driving:

• Adaptive Cruise Control System Function Failure: The ACC main function indicator light extinguishes or displays "Unavailable" status; the vehicle cannot automatically adjust speed based on the distance to the preceding vehicle.
• Radar Control Unit Warning Information: Related prompts regarding unavailable front sensors pop up on the instrument panel display or central multimedia system.
• Lane Keeping Assist Restricted: The LKA function, which relies on the same radar data source, may subsequently exit or become limited for use because the control unit lacks basic configuration support.
• Inability to Recover After System Reset: Attempting to restart the vehicle or switch the ACC switch maintains the fault status, and DTC records cannot be cleared via conventional software reset.
• Abnormal Icon Illumination: Some models may display a yellow exclamation mark or abnormal blinking signal next to the dashboard icon corresponding to the radar sensor.

Core Fault Cause Analysis

According to technical diagnostic logic, potential factors leading to the generation of B2CE655 fault code are mainly classified into three hardware and software dimensions:

• Hardware Component Abnormality: The physical module of the front millimeter-wave radar assembly has an internal fault, preventing it from returning NVM read status normally to the control unit (Ecu); or the vehicle did not burn valid radar function configuration data into non-volatile memory upon going off the line.
• Wiring and Connector Connection Issues: The communication harness connecting the radar sensor and control unit has risks of open circuit or short circuit, preventing the control unit from acquiring a complete memory map table at startup; additionally, oxidation of radar plug terminals or poor contact hinders physical reading of configuration information.
• Controller Logic Operation Abnormality: The internal storage unit of the body domain control module or radar gateway controller experiences data corruption; or its software logic fails to correctly parse the data stream in NVM during startup self-check, leading to misjudgment as "No Information".

Technical Monitoring and Trigger Logic

The judgment of fault code B2CE655 follows strict temporal logic and state machine monitoring mechanism. The specific process is as follows:

• Monitoring Target: System monitors the functional configuration area of the front millimeter-wave radar in Non-Volatile Memory (NVM) in real time.
• Value Range Judgment: When the control unit reads NVM memory address, if the value of key configuration bytes is invalid or empty, it does not meet the expected configuration bit mask requirements.
• Trigger Condition: Fault only triggers in power-off restart scenarios, specifically after the Start Switch is placed in ON gear. Once the ignition key rotates to ON position or one-touch start succeeds, entering the Initialization Phase.
• Fault Judgment Logic: When the vehicle completes power-up, the control unit attempts to read radar NVM configuration data; if effective configuration information (no feature code or checksum mismatch) is not detected within a pre-defined time window, the fault status is immediately locked and DTC B2CE655 is set. This logic aims to ensure that without necessary calibration data, radar function is not forced activated to prevent system malfunction.