B1CEB13 - B1CEB13 Right Footwell Light Drive Circuit Open Circuit Fault

Fault Depth Definition

B1CEB13 is defined as "Right Floor Lamp Driver Circuit Open Fault", which is a key diagnostic code in the vehicle electrical architecture. This DTC indicates that when the Left Domain Controller monitors the output drive circuit of the Right Floor Lamp, it detects an interruption in physical connection or impedance abnormality. In this system, the Left Domain Controller serves as the central logic computation unit responsible for managing the activation and status maintenance of the body lighting system. The so-called "driver circuit open" refers to an unexpected open state between the driver module and the controlled lamp, where either the power supply path or control signal path is disconnected, resulting in current unable to form a complete loop and rendering the actuator ineffective. This DTC reflects that the closed-loop feedback mechanism of the Control Unit regarding the output load has triggered an interruption judgment.

Common Fault Symptoms

When the system activates fault monitoring logic, the vehicle will exhibit the following perceptible driving experience anomalies and instrument feedback:

• Function Loss: After turning on the Right Floor Lamp switch, the Right Floor Lamp completely fails to light up, even when in an "On" instruction state.
• Lighting Loss: Interior right foot area lighting failure, affecting the driver's perception of visibility for the pedal area.
• Fault Indicator: The relevant diagnostic system will record and lock this specific fault status in the background, possibly accompanied by intermittent false alarms or continuous alarms.

Core Fault Cause Analysis

According to the B1CEB13 determination logic, the root causes of faults can be summarized into the following three dimensions of physical or electronic anomalies:

• Hardware Components (Actuators): The Right Floor Lamp itself suffers internal damage, such as burned-out bulb, open LED module, or failed driver module, causing it to respond abnormally to control instructions.
• Wiring/Connectors (Physical Connection): Harness or connectors have open circuit faults, including power line interruption, poor grounding, or connector pin retreat, causing electrical pass-through to disconnect.
• Controller (Logic Computation): Abnormalities occur in the internal driver chip or output stage circuit of the Left Domain Controller, causing it to be unable to correctly output drive voltage or complete monitoring/judgment of the load.

Technical Monitoring and Trigger Logic

The generation of this DTC is based on real-time sampling and logical comparison of specific electrical parameters by the Left Domain Controller. Specific monitoring mechanisms are as follows:

• Monitoring Target: The Control Unit primarily monitors the continuity status of the Right Floor Lamp driver circuit, including signal voltage, load feedback, and circuit conduction status.
• Value Range: The key condition for triggering fault judgment is that the controller output voltage is between $9V$~$16V$. Within this voltage window, if no current or specific state absence is detected, it is considered abnormal.
• Judgment Condition: When executing diagnosis, the system checks for the real-time status of driver circuit open, and this logic performs continuous validation while the Right Floor Lamp is in a constant-on state (monitoring context). When the above voltage interval is met and an open circuit criterion exists simultaneously, the system will generate B1CEB13 DTC.