how to fix P0301 misfire code on BMW X3 G01 (2018-2024)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shock.
• Allow the engine to cool before starting work.

2. Inspect and Replace Spark Plug

• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Disconnect the ignition coil connector at cylinder 1.
  3. Unbolt and remove the ignition coil.
  4. Remove the spark plug using a spark plug socket.
  5. Inspect the spark plug for wear; replace if necessary.
  6. Install a new spark plug, ensuring proper torque (typically 22 lb-ft).
  7. Reinstall the ignition coil and connector.

3. Check and Replace Ignition Coil (if necessary)

• Sub-steps:
  1. If the ignition coil was damaged during inspection, replace it with a new unit.
  2. Ensure the coil is seated properly in the spark plug well.
  3. Reconnect the ignition coil connector securely.

4. Inspect and Test Fuel Injector

• Sub-steps:
  1. Disconnect the fuel injector connector.
  2. Remove the fuel injector from the rail (ensure fuel pressure is relieved before this step).
  3. Test the injector for resistance with a multimeter (typically 12-16 ohms).
  4. If the injector is faulty, replace it with a new one.
  5. Reinstall the fuel injector, ensuring it seals properly against the rail.

5. Perform a Compression Test

• Sub-steps:
  1. Remove the spark plug from cylinder 1 again.
  2. Insert a compression gauge into the spark plug hole.
  3. Crank the engine for a few seconds and record the compression reading.
  4. If the reading is below the manufacturer's specifications, further diagnose potential internal engine issues.