Description:

The error code, ATC 524219.02, is triggered when the control unit detects that the frequency from the defog sensor (B143, lead 2003) is outside the valid frequency range (32.26 – 37.88 Hz). Deviations from the specified frequency range can indicate a malfunction within the sensor or associated circuitry, affecting its ability to accurately detect fogging conditions on the vehicle’s windows.

Reaction:

This fault may lead to improper activation or non-activation of the defogging system, potentially compromising visibility and safety during conditions where window defogging is necessary.

Recommendations:

• Inspect Sensor and Wiring: Check the defog sensor and its wiring for signs of damage, corrosion, or loose connections that might affect frequency readings.
• Measure Sensor Frequency: Use appropriate diagnostic tools to measure the frequency output of the defog sensor to verify if it falls within the specified range.
• Replace or Repair Faulty Sensor: If the sensor is found to be producing incorrect frequencies consistently, consider replacing it or repairing any issues in its circuitry.
• Test System Functionality: After any repairs or replacements, test the defog system to ensure it activates correctly based on the sensor’s readings.
• Reset Fault Codes and Recheck the System: Clear any fault codes from the system and perform a complete check to ensure no further issues are present and that the sensor is functioning within its normal operational range.

Note:

Regular checks and maintenance of environmental sensors like the defog sensor are critical for ensuring they function effectively and reliably. These sensors play a crucial role in maintaining clear visibility and safe driving conditions, making their proper operation fundamental to vehicle safety and comfort. Addressing issues promptly helps maintain system reliability and prevent visibility-related hazards.