B1C1300 - Trunk Lock Fault

B1C1300 Fault Definition

DTC B1C1300 is a diagnostic error code reported by the vehicle Rear Domain Controller regarding the trunk lock actuator. This fault code plays a role in status monitoring and closed-loop verification within the entire vehicle control system, primarily used to ensure the integrity of the trunk unlock action. From a control logic perspective, this fault indicates that the system failed to detect the expected mechanical state feedback during specific operation sequences (such as remote or internal switch triggering), or the timing response within the execution cycle does not meet preset safety standards. It involves the control unit's composite monitoring of motor power supply lines, actuator movement, and final physical position, representing an abnormal signal recording for critical safety and comfort functions.

Common Fault Symptoms

Based on driver perception and system feedback performance expanded from raw data, when DTC B1C1300 is recorded, users may observe the following specific phenomena during driving or daily life:

• When operating the trunk door switch (including remote key, interior button, or micro-switch), the trunk door shows no response, and the mechanical structure performs no action.
• The system cannot complete the preset "Unlock - Detect" closed-loop process, causing the lock motor to fail to enter the expected working state.
• When reading this code with diagnostic equipment, it displays that the status error count has reached the recording threshold, indicating a continuous abnormality in the function module.

Core Fault Cause Analysis

According to fault mechanisms and vehicle electrical architecture, the triggering of B1C1300 mainly stems from potential hardware or logical issues in the following three dimensions:

• Hardware Components: A physical fault occurs inside the electric rear door lock (actuator), such as motor coil open circuit, mechanical transmission mechanism jamming or wear, preventing response to power-on commands.
• Lines/Connectors: Wiring connecting the motor and controller has open or short circuit phenomena, or connector terminal poor contact, oxidation loosening, causing power supply line abnormalities or signal transmission blockage.
• Controller: Abnormal logic computation occurs inside the Rear Domain Controller, unable to normally parse state feedback data or misjudge faults under specific operating conditions, leading to cumulative wrong judgment counts.

Technical Monitoring and Trigger Logic

This system's monitoring mechanism adopts time window superposition counting logic to exclude occasional interference and lock persistent hardware faults. Specific trigger conditions and technical parameters are as follows:

• Set Fault Conditions: When performing unlock actions on the trunk such as remote or micro-switch, and after the system confirms the trunk lock motor power supply line has no fault, the controller enters a specific monitoring window. The monitoring time node is set to $200\text{ms}$ after the trunk lock motor power is cut off.
• Trigger Logic Explanation:
  • The system detects the actual state within this time window; once the trunk is detected to be in a "closed" state (not matching the expected unlock state), the system adds 1 to the status error count.
  • The fault judgment threshold is set to record a fault if continuous cumulative state errors reach $4$ times. This means a single test failure will not trigger DTC; only after satisfying four repetitive state error logic judgments will B1C1300 fault code be formally generated and relevant fault indicator lights (if applicable) illuminated.