P2B6F24 Electronic Fan 1 Voltage Fault

Fault Depth Definition

P2B6F24 Electronic Fan 1 Voltage Fault refers to a condition where the Vehicle Control Unit (VCU) or relevant control unit detects that the voltage signal in the power supply circuit and status monitoring of the first electronic fan exceeds the preset normal operating threshold. In the vehicle thermal management system architecture, this control unit is responsible for real-time monitoring of the execution status of each cooling component, ensuring the cooling system operates according to the expected load curve through feedback loops. This fault code indicates abnormal electrical signals collected by the voltage sensor or power drive module, directly relating to the vehicle's overall thermal management feedback performance. In the electronic electrical architecture, this fault usually means the controller cannot accurately know the actual working load status of Electronic Fan 1, potentially affecting the execution precision of cooling control strategies.

Common Fault Symptoms

When the P2B6F24 code is recorded, the vehicle may exhibit the following perceptible functional abnormalities or instrument feedback:

• Reduced Thermal Efficiency: Due to abnormal electronic fan speed control, it may lead to an increased rate of coolant temperature rise, affecting the heat dissipation efficiency of the engine or battery pack.
• Limited Driving Experience: Under high-speed or heavy-load conditions, insufficient heat dissipation capacity may trigger power management system frequency reduction protection to reduce thermal load.
• Instrument Warning Light Prompt: After the diagnostic tool reads the fault code, the driver center information display screen or dashboard may show specific cooling system warning icons (e.g., fan icon lit up).
• Dynamic Performance Fluctuation: Under dynamic operating conditions requiring high-frequency heat dissipation, the vehicle control system may limit electronic acceleration functions to ensure thermal safety.

Core Fault Cause Analysis

Based on the fault logic architecture, the causes of this fault can be categorized into the following three technical dimensions:

• Hardware Component Abnormality: Electronic Fan Failure involves physical damage to motor internal coils, Hall sensors, or carbon brushes (if equipped), leading to changed load characteristics and resulting in voltage signal fluctuations. This belongs to actuator body performance degradation or failure.
• Line/Connector Integrity Damaged: Harness or Connector Failure refers to unreliable physical connections in the power circuit, including short circuits to ground caused by damaged insulation layers, or open circuits or loose connections caused by harness wear. Such issues directly cause attenuation, spikes, or voltage loss during voltage signal transmission.
• Controller Logic Calculation Deviation: Vehicle Controller Failure involves aging of internal power drive circuits, sampling resistor drift, or software calibration data errors in the control unit, causing the controller to mistakenly judge normal voltage feedback as an abnormal state.

Technical Monitoring & Trigger Logic

The control unit identifies this fault through specific diagnostic strategies, with its judgment logic strictly following the following technical parameters and timing requirements:

• Monitoring Target: Mainly monitors the circuit supply voltage (Supply Voltage) provided to the first electronic fan. The system continuously collects real-time voltage values at this node, comparing them against the normal threshold range.
• Numerical Judgment Range: During motor operation, if the instantaneous voltage value monitored deviates from the standard range $U_{fault}$ ~ $U_{normal}$ (here referring to exceeding the system preset normal voltage fluctuation tolerance), the system will judge it as an abnormal signal.
• Trigger Condition: Formal setting of the fault code requires satisfying the following timing logic:
  1. IGN ON (Ignition Switch On): The diagnosis program only activates when ignition power is on and the vehicle enters the running monitoring mode.
  2. DTC Setting Enabled (Diagnostic Trouble Code Enabled): The system confirms that the current fault signal persists beyond a preset timer threshold, and is not reset by transient voltage interference, confirming persistent hardware or control abnormality.