C1E2E00 Request Control ACCAebaxTar Invalid - Technical Diagnostic Explanation

Detailed Fault Definition

The DTC C1E2E00 plays a critical role in domain communication diagnosis within the vehicle's electronic architecture. This code clearly indicates that at the control logic level of the intelligent power brake system, an instruction to "Request Control ACCAebaxTar" from the upper-level strategy is judged invalid by the receiver or its own processing unit. From a system principle analysis, this signal involves the core instruction link for the cooperative operation of Adaptive Cruise Control (ACC) and Automatic Emergency Braking (AEB). After the control unit generates an execution command, if expected feedback confirmation is not received, or state parameters exceed preset logic thresholds, the system immediately marks the request status as "Invalid". This belongs to high-level interaction diagnosis indicators in the vehicle active safety domain, directly linked to the real-time decision-making capability of the underlying power brake system, signal integrity, and logical closure of the execution chain, which is a key feedback node for ensuring stable operation of the driver assistance system.

Common Fault Symptoms

Based on existing data analysis, when DTC C1E2E00 is recorded, the phenomena perceived by car owners in driving experience are mainly manifested as system function degradation or safety warnings:

• Restricted System Functionality: Some auxiliary functions of the intelligent power brake system cannot operate normally. Specifically, icons for functions such as Adaptive Cruise Control and Automatic Emergency Braking may turn off, or the system enters a safety protection mode (such as exiting L2 assistance), causing the vehicle to be unable to intervene in speed according to preset strategies.
• Instrument Cluster Warning Feedback: The multi-function display screen or dedicated warning lamp inside the cockpit may show related fault prompts. The system will display specific warning information regarding the intelligent power brake part on the driver information center, guiding owners to confirm vehicle status.
• Abnormal Dynamic Response: Under operating conditions requiring highly automated intervention (such as emergency obstacle avoidance or following), the system may not be able to execute deceleration strategies as expected. Although basic braking functions are retained, auxiliary braking enhancement functions are missing, requiring drivers to maintain more conventional attention distribution to maintain safety.

Core Fault Cause Analysis

The triggering mechanism of this fault code can be attributed analysis from three dimensions of hardware and logic levels, including hardware component failure, line connection abnormalities, and controller logic errors:

• Hardware Components (Sensor End): Front-range Millimeter Wave Radar Failure is one of the direct sources of signal invalidity. When the radar unit suffers internal hardware damage, unstable power supply, or fails to correctly collect key physical data such as target distance and relative speed, the upper-level control logic cannot effectively calculate "ACCAebaxTar" control request calculations based on this data, thereby generating an invalid status mark at the source.
• Controller Logic Computation: Intelligent Power Brake Controller Failure involves logical processing abnormalities within the Electronic Control Unit (ECU). If communication protocol parsing fails inside the controller, software state machines get stuck in error commands, or power management modules experience instantaneous fluctuations, it will lead to the system being unable to correctly determine the validity of external requests, thereby falsely reporting this fault code.
• Wiring and Physical Connections: Harness and Connector Failure involves the physical link integrity of signal transmission. This includes electromagnetic interference (EMI) caused by damaged shielding layers, high-impedance states caused by poor pin connections, or poor ground loops, all of which can cause control commands to undergo bit flipping, loss, or misreading as invalid status during transmission, ultimately triggering diagnostic logic.

Technical Monitoring and Trigger Logic

The system monitors specific fault determination operating conditions via high-precision signal processing algorithms and stores DTC based on strict trigger conditions:

• Monitoring Target: The system focuses on monitoring the integrity of physical data streams and control request signals from the radar end. Specific parameters include the status value (Valid/Invalid indicator) of the ACCAebaxTar control word, communication message cycle, signal voltage stability, and node response time on the CAN bus. The system aims to ensure that all participating components maintain consistent logical states during dynamic processes.
• Trigger Condition Logic: The judgment of this fault is strictly based on specific ignition cycle conditions. After the ignition switch is placed in the "ON" position, the system completes power-on self-test (POST) and enters real-time operation monitoring mode. If, after initialization, the controller detects that the ACCAebaxTar control request remains invalid, communication times out, or exceeds the preset allowed time window, it will immediately lock the fault status and store DTC C1E2E00.
• Judgment Boundary: This process is only carried out during dynamic monitoring when the intelligent power brake system is activated, ensuring that no false positives are generated when the vehicle is stationary and auxiliary functions are not called. Trigger conditions depend entirely on the validity of the start signal; once "ON" position conditions are met and logical monitoring continuously finds requests invalid, it is regarded as a fault establishment, and may be accompanied by freeze frame data recording for subsequent diagnostic analysis.