my Volkswagen Golf MK7.5 (2020-Present) check engine light came on what does it mean

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is off.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Retrieve DTCs

• Connect the OBD-II scanner to the vehicle’s diagnostic port.
• Turn the ignition to the "ON" position without starting the engine.
• Record all stored DTCs and any pending codes for further analysis.

3. Addressing Common Issues

• If DTC indicates a faulty oxygen sensor:

  • Locate the oxygen sensor based on the DTC.
  • Disconnect the electrical connector and remove the sensor using an O2 sensor socket.
  • Install the new oxygen sensor and reconnect the electrical connector.

• If DTC indicates a misfire (e.g., P0300-P0304):

  • Inspect and replace spark plugs if worn or fouled.
  • Test ignition coils using a multimeter for proper resistance.
  • Replace faulty ignition coils if necessary.

4. Clear DTCs

• After repairs, reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the DTCs from the vehicle's memory.
• Turn the ignition to "ON" and check if the check engine light is still illuminated.

5. Final Inspection

• Start the engine and allow it to reach operating temperature.
• Monitor engine performance and check for any unusual sounds or behaviors.
• Conduct a brief test drive to ensure the check engine light does not reappear.