B1CE313 - B1CE313 Right Outside Mirror Up/Down Adjust Motor Drive Circuit Open Circuit Fault

Fault Definition Detail

DTC B1CE313 is defined as "Right Exterior Rearview Mirror Up/Down Switching Motor Drive Circuit Open Circuit Fault". In automotive electronic control architecture, this diagnostic fault code directly points to electrical connection integrity anomalies in the vertical positioning actuator of the right exterior rearview mirror. The Domain Controller is responsible for managing body electrical system functions. When the system attempts to send commands to the up/down switching motor via the drive circuit, an unexpected interruption in signal voltage or current is detected in the feedback loop. Such open circuit phenomena indicate that the physical-level conduction path has failed, preventing the control unit from establishing an effective energy transfer link to the actuator, falling under severe underlying hardware communication or power supply anomalies. Writing of this fault code indicates the system has confirmed the electrical pathway was in a disconnected state during specific operations, requiring attention to the motor drive level, power output path, and consistency of internal logic judgments.

Common Fault Symptoms

• Function Failure Feedback: When the driver attempts to operate the right exterior rearview mirror for vertical (up/down) adjustment via control switches, the mirror body has no response or position change.
• No Output Signal in Operation: Although the start switch is set to ON, after issuing the adjustment command, the mechanical structure of the rearview mirror does not produce the corresponding physical displacement.
• System Status Indicator: Specific fault event codes are recorded in relevant vehicle diagnostic interfaces, and some vehicles may be accompanied by self-check warnings of the rearview mirror control module or related function disable logic.

Core Fault Cause Analysis

For the determination logic of DTC B1CE313, technical-level attribution analysis can be conducted from the following three dimensions:

• Hardware Component Layer (Motor): The windings are open internally in the right exterior rearview mirror up/down switching motor, internal drive bridge damage or permanent magnet demagnetization causing inability to respond to electrical signal input.
• Line and Connector Layer (Physical Connection): Body harnesses break due to long-term vibration or wear, leading to circuit open circuits; simultaneously, connector terminals experience physical contact interruption due to oxidation corrosion, loose locking tabs, or pin withdrawal.
• Controller Layer (Logical Operation): The power tube responsible for drive output inside the right domain controller fails, or the input port for monitoring motor feedback signals exists abnormal open-circuit logic, causing the system to misjudge the circuit state as open.

Technical Monitoring and Trigger Logic

The control unit's judgment on this fault follows strict timing and signal analysis logic. Specific technical details are as follows:

• Monitoring Target: The system continuously monitors in real-time the electrical characteristics of the drive loop for the right exterior rearview mirror up/down switching motor, focusing on detecting conductivity status (Electrical Continuity) and load response features between the control output node and the motor end.
• Value Range: Under open circuit fault mode, monitored circuit voltage or current characteristic values will show as open-circuit levels (i.e., no expected current flow).
• Trigger Conditions: The activation conditions for the fault code are explicitly limited to the start switch set to ON state. Only when the driver actively operates the right exterior rearview mirror up/down switching function and the control unit detects open circuit characteristics in the drive circuit will the system formally determine this fault and store DTC B1CE313.