B225813 - B225813 Sunshade Motor Open Circuit

meaning of this fault code is "open circuit," referring to an open electrical pathway from the control unit output terminal to the motor actuator. When the vehicle management system attempts to drive the sunshade movement via pulse signals or DC, the internal current monitoring loop of the control unit fails to receive expected load feedback. This typically implies infinite impedance in the drive circuit, preventing current from closing the loop, thereby triggering the fault protection mechanism. This definition covers the state determination of the entire electrical link from the controller pin to the motor coil.

Common Fault Symptoms

Based on the trigger logic of fault code B225813, vehicles typically exhibit the following perceptible anomalies at the user interaction level:

• No Response: When the driver presses the sunshade lift switch, the sunshade mechanical structure remains stationary, completely losing the ability to execute commands.
• System Warning Anomaly: Some vehicle models will display warning icons or text messages indicating restricted sunshade functionality on the dashboard or central control screen.
• Function Lock State: Even after restarting the vehicle power, the protection logic corresponding to this fault code usually does not release immediately, causing the control unit to continue shielding output instructions for the motor.

Core Fault Cause Analysis

Regarding the failure mechanism of fault code B225813, it can be categorized and analyzed from the following three hardware and software logic dimensions:

• Hardware Component Failure (Sunshade Motor): Internal motor winding opens, coil burns out, or permanent magnets demagnetize, causing it as an inductive load to fail to generate back-EMF or absorb current.
• Line and Connector Failure (Physical Connection): Wiring harness connecting the Right Domain Controller and sunshade motor breaks; insulation layer damage; or pins in intermediate connectors recede, oxidize, corrode, and have excessive contact resistance, interrupting the current path.
• Controller Failure (Logic Operation): Power transistors or MOSFETs inside the Right Domain Controller responsible for driving motor output are damaged, causing the control unit to fail sending effective voltage pulse signals to the motor, thus being misjudged as an external open circuit.

Technical Monitoring and Trigger Logic

The determination of this fault code is based on current detection algorithms and voltage threshold windows inside the Right Domain Controller. Specific monitoring targets include:

• Monitoring Target: System monitors real-time current feedback values during sunshade motor operation, focusing on verifying whether minimum load current requirements are met.
• Numerical Range Limitation: Electrical environment for fault determination must be within the power voltage range of $9V \sim 16V$.
• Trigger Condition Determination: Only when the Right Domain Controller issues commands to drive the sunshade motor (i.e., "set fault condition"), if the control unit's internal current sensor detects loop current below threshold or zero, the system will immediately mark this state as "No Current Detected" when the above voltage environment is met. Once entering "Trigger Fault Condition," the system will solidify fault code B225813 and record corresponding data stream snapshots for subsequent

Cause Analysis Regarding the failure mechanism of fault code B225813, it can be categorized and analyzed from the following three hardware and software logic dimensions:

• Hardware Component Failure (Sunshade Motor): Internal motor winding opens, coil burns out, or permanent magnets demagnetize, causing it as an inductive load to fail to generate back-EMF or absorb current.
• Line and Connector Failure (Physical Connection): Wiring harness connecting the Right Domain Controller and sunshade motor breaks; insulation layer damage; or pins in intermediate connectors recede, oxidize, corrode, and have excessive contact resistance, interrupting the current path.
• Controller Failure (Logic Operation): Power transistors or MOSFETs inside the Right Domain Controller responsible for driving motor output are damaged, causing the control unit to fail sending effective voltage pulse signals to the motor, thus being misjudged as an external open circuit.

Technical Monitoring and Trigger Logic

The determination of this fault code is based on current detection algorithms and voltage threshold windows inside the Right Domain Controller. Specific monitoring targets include:

• Monitoring Target: System monitors real-time current feedback values during sunshade motor operation, focusing on verifying whether minimum load current requirements are met.
• Numerical Range Limitation: Electrical environment for fault determination must be within the power voltage range of $9V \sim 16V$.
• Trigger Condition Determination: Only when the Right Domain Controller issues commands to drive the sunshade motor (i.e., "set fault condition"), if the control unit's internal current sensor detects loop current below threshold or zero, the system will immediately mark this state as "No Current Detected" when the above voltage environment is met. Once entering "Trigger Fault Condition," the system will solidify fault code B225813 and record corresponding data stream snapshots for subsequent