B2CEC00 - B2CEC00 CMRR ADAS Core System Detected Abnormal Data

Fault Depth Definition

B2CEC00 CMRR ADAS Core System Analysis of Abnormal Data is a key diagnostic trouble code (DTC) appearing in vehicle active safety systems. This code is primarily associated with the communication and data verification mechanism between the CMRR (Radar/ADAS) control unit and the DAcore core calculation module. In the vehicle's full-vehicle network architecture, this fault code indicates that when the ADAS core system performs real-time environmental perception and path planning, the raw sensor data or fused calculation results received fail the confidence check inside the DAcore. This fault code trigger implies that the system has identified an abnormality in the trustworthiness of key parameters output by the front millimeter-wave radar (such as vehicle dimensions, attitude angular velocity compensation information, and dynamic target features), causing the control unit to initiate protective logic. This definition covers the consistency verification process from physical layer signal acquisition at the sensors to the internal data processing algorithm of the Electronic Control Unit (ECU), serving as a key monitoring indicator for ensuring ADAS Advanced Driver Assistance Systems functional safety.

Common Fault Symptoms

When fault code B2CEC00 is stored or currently present, the following perceptible feedback phenomena occur between the driver and the vehicle's onboard intelligent system:

• Adaptive Cruise Control (ACC) Function Failure: The Adaptive Cruise indicator light on the dashboard illuminates, and the system cannot maintain the set speed or keep a safe following distance from the preceding vehicle.
• Driver Assistance System Warning Prompts: The central information display screen or instrument cluster may pop up text warnings such as "Sensor Abnormal", "Data Untrustworthy", or similar ADAS function restriction messages.
• Limited Partial Perception Functions: Advanced vehicle alerts (such as forward collision warning) may be temporarily disabled to ensure the driver can fully take control.
• System Status Indicator Anomaly: The DAcore core system status light may show a solid illumination or intermittent flashing, reflecting the state of internal data flow verification failure.

Core Fault Cause Analysis

Technical analysis targeting this fault code requires investigation from three dimensions: hardware components, physical connections, and controller logic:

1. Hardware Component Anomaly (Front Millimeter Wave Radar)
   • The front millimeter-wave radar serves as the data acquisition source; its internal transmit/receive modules may experience signal processing deviation. When hardware performance degrades, output fundamental parameters (such as distance, speed) may deviate from the physical model range expected by the DAcore algorithm, leading DAcore to judge it as untrustworthy data.
2. Line and Connector Status (Physical Connection)
   • If the communication line from the radar to the control unit has excessive contact resistance or signal attenuation, it may cause fluctuation in the tire size (tire size) parameter transmitted to DAcore. Physical layer interference may cause offset in yawrate (yaw rate) compensation data during transmission, thereby satisfying fault judgment conditions.
3. Controller Logic Operation (DAcore Core Algorithm)
   • As the data processing center, high sensitivity of its internal filtering algorithms or sensor fusion logic to specific operating conditions may misjudge signal fluctuations within a normal range as abnormal. Additionally, the status of the public CAN network directly affects the integrity of data uploaded to DAcore; if the network state does not enter busoff (Bus Off) protection state but data quality declines, DAcore will judge target data untrustworthy based on preset logic and store the fault code.

Technical Monitoring and Trigger Logic

The DAcore core system captures the above anomalies through specific real-time monitoring mechanisms. Its trigger logic follows strict timing and numerical conditions:

• Monitoring Target Details

  • Tire Size (tire size) Data Validity Verification: System continuously monitors the confidence level of vehicle geometric parameter data.
  • Yaw Rate Compensation (yawrate compensation) Data Integrity Check: Monitor whether compensation values used for dynamic attitude correction meet physical logic requirements.
  • Dynamic Target Data (target data) Tracking Information Verification: Real-time analysis of ADAS perception data quality for the preceding vehicle and other obstacles.

• Fault Judgment Trigger Timing and Conditions

  • Initialization Delay Threshold: Fault monitoring only begins effective evaluation after $3s$ following vehicle power-up initialization completion. During this period, the system is in self-check status and does not generate this fault code temporarily.
  • Operation Mode Restriction: Faults are recorded only when the vehicle is in a non-"Factory Mode" off state, excluding interference from debugging or engineering modes.
  • Network Communication State Constraint: Judgment must be performed under the condition that the public CAN communication link has not entered busoff status. If the bus is disconnected (busoff), the system will prioritize handling communication loss faults rather than this analysis anomaly code.

• Trigger Condition Summary DAcore activates fault storage logic immediately when it detects any one of the following conditions:

  1. tire size shows untrustworthy data;
  2. yawrate compensation data is untrustworthy;
  3. Target data (target data) is untrustworthy.

Once any of the above conditions is confirmed by DAcore after power-on $3s$ and not in factory mode, fault code B2CEC00 is written to storage and notifies the dashboard cluster to illuminate relevant warnings.