B1CE013 - B1CE013 Left Outside Mirror Up-Down Motor Drive Circuit Open Circuit Fault

Fault Definition Depth

B1CE013 refers to a specific system error code in the vehicle electronic electrical architecture concerning the vertical adjustment function of the left outside rearview mirror. The core localization of this DTC is "Drive Circuit Open," which technically means that during the process where the control unit sends drive instructions to the motor, the current detection loop fails to detect the expected load current response. In system communication and control logic, the Left Domain Control Unit is responsible for monitoring real-time operation status of the left and right outside rearview mirror motors. This fault indicates that during the execution of vertical adjustment action, electric motor current acquisition signals are missing or unable to close, causing the control system to judge as circuit open or load abnormal failure, thereby triggering fault protection mechanisms to ensure safe and stable electrical systems for the whole vehicle.

Common Fault Symptoms

When a left outside rearview mirror vertical actuator motor drive circuit open fault occurs, the vehicle control logic will enter degradation operation mode, and during driving, the car owner may observe the following specific manifestations:

• Vertical Adjustment Function Failure: The left outside rearview mirror cannot execute up/down angle adjustment instructions, regardless of mechanical handle operation or electronic button activation.
• Dynamic Feedback Missing: When attempting to adjust mirror position, if in auto scan or manual drive mode, the motor has no action feedback and the system no longer records the position status of that motor.
• Instrument Warning Signal: The driver information center dashboard of some vehicle models may display "Rearview Mirror Fault" or similar icon alerts, informing the user that a specific control channel is unavailable.

Core Fault Cause Analysis

For DTC B1CE013, from the reliability design perspective of the vehicle electronic architecture, its fault source can be precisely divided into three dimensions for technical troubleshooting:

• Hardware Component (Actuator Layer): Internal open circuit damage in the left outside rearview mirror vertical adjustment motor, coil burnout or Hall sensor signal failure, resulting in inability to form effective loop.
• Line and Connector (Transmission Layer): Wiring connecting Left Domain Control Unit with rearview mirror motor appears open circuit, insulation skin damaged grounding, or relevant terminal connector loose, pin oxidized corrosion, causing drive current path interruption.
• Controller (Logic Operation Layer): Motor drive MOS tube damage or current sampling circuit abnormality inside Left Domain Control Unit, resulting in inability to correctly output drive signal or accurately acquire current loop, thus falsely reporting open circuit fault.

Technical Monitoring and Trigger Logic

The generation of this DTC follows a rigorous real-time diagnostic algorithm; its triggering mechanism is based on multi-parameter joint determination, specific logic thresholds and conditions are as follows:

• Monitoring Target: System continuously monitors left outside rearview mirror vertical actuator motor drive current (Drive Current) in real time.
• Numerical Range Determination: Diagnosis only valid within safe operation window where system supply voltage stabilizes at $9V$~$16V$, below or above this range may affect sampling accuracy.
• Dynamic Trigger Condition: When driver issues vertical adjustment command and enters "Left Outside Rearview Mirror Vertical Actuator Motor Working" state, diagnostic program activates; if drive current continuously detected as $0$ (i.e., no load current characteristics) at this time, system starts timing.
• Fault Lock Timeout: If the above no-current status continues for $3s$ or more, controller will no longer perform adaptive learning or intermittent reset attempts, confirmed as persistent open circuit, finally determining fault B1CE013 valid and lighting up related warning lights.

This logic ensures strict monitoring on actuator loop integrity when vehicle starts (ON gear) under normal working voltage environment.