how do I diagnose a P0301 code on my Volkswagen Golf MK7.5 (2020-Present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Replace Spark Plug

• Remove the engine cover (if applicable) using a socket set.
• Carefully detach the ignition coil from the spark plug by pulling the connector straight off.
• Use a spark plug socket to remove the old spark plug.
• Inspect the spark plug socket for debris before installing a new spark plug.
• Torque the new spark plug to the manufacturer’s specification (usually around 22 lb-ft).
• Reattach the ignition coil and ensure the connector is securely fastened.

3. Inspect and Replace Ignition Coil (if necessary)

• If the ignition coil is found faulty during the inspection, remove it from the spark plug.
• Unscrew the ignition coil securing bolts using a socket.
• Disconnect the electrical connector from the ignition coil.
• Install the new ignition coil in reverse order of removal, ensuring it is seated properly.
• Torque the ignition coil bolts to the specified value.

4. Fuel Injector Test

• Disconnect the fuel injector connector for cylinder 1.
• Use a multimeter to test the resistance of the fuel injector and replace if it is out of specification.
• Reconnect the injector before turning the ignition on to avoid fuel leaks.

5. Compression Test

• Remove the spark plug from cylinder 1.
• Insert the compression tester into the spark plug hole and crank the engine to take a reading.
• Compare the reading with the manufacturer's specifications. If low, further investigation into engine internals may be required.