B1C0800 - Rear Wiper Reset Signal Fault

Fault Definition

Fault Code B1C0800 indicates abnormal communication of the rear wiper reset signal in the vehicle's body electronic system. In this control logic, the Left Domain Controller acts as the core processing unit, responsible for receiving position feedback pulse signals from the rear wiper motor to confirm whether the wiper arm has returned to the mechanical zero point (Park Position). When the feedback loop is interrupted, signal validation fails, or communication link is lost, the control unit cannot confirm the physical position status of the actuator, thereby recording this diagnostic fault code. This fault involves integrity verification of the signal chain and belongs to a key diagnostic item of the body comfort system.

Common Fault Symptoms

• When the rear wiper stops operating, the wiper arm stays at an arbitrary position on the windshield and cannot automatically return to the bottom hidden area.
• The vehicle dashboard may illuminate the body system warning light or display a rear wiper system fault message.
• After turning off the ignition switch or disabling the wiper function, the rear wiper motor cannot execute the expected automatic reset action.
• Rear wiper function may be limited, available only in specific modes, or completely unavailable.

Core Fault Cause Analysis

• Hardware Component: Internal reset switch or Hall sensor failure within the rear wiper motor, resulting in the inability to generate correct physical position feedback signals, causing the control unit to fail to identify the motor stop position.
• Wiring/Connector: Harness between the motor and control unit has open circuits, shorts, or connector oxidation/corrosion, leading to interruption of the signal transmission physical link or abnormal signal level.
• Controller: Abnormal internal signal processing circuit or logic operation unit within the Left Domain Controller, unable to correctly parse received reset signals, leading to signal judgment logic errors.

Technical Monitoring and Trigger Logic

• Monitoring Target: The system monitors in real-time the reset signal level status and pulse count integrity feedback from the rear wiper motor, ensuring no distortion occurs during signal transmission.
• Trigger Condition: This fault is typically triggered during the dynamic monitoring phase after the wiper motor executes a stop command, with the system expecting to receive an effective reset confirmation signal within a specific time window $t_{window}$.
• Logic Judgment: When the control unit detects signal loss, signal duration exceeds a preset range, or signal status does not meet preset logical thresholds (e.g., $\text{Signal}_{status} \neq \text{Valid}$), it determines a reset signal fault and stores the fault code.