my BMW X3 F25 (2011-2018) check engine light is on with code P0301, how to fix?

Solution

1. Preparation

• Tools Required: OBD-II scanner, compression tester, multimeter, socket set, torque wrench, replacement spark plug, replacement ignition coil (if necessary).
• Ensure the vehicle is parked on a flat surface and the engine is cool.

2. Replace Spark Plug

1. Disconnect the negative battery terminal.
2. Remove the engine cover (if applicable) using a socket set.
3. Locate the spark plug for cylinder 1.
4. Use a spark plug socket to remove the old spark plug.
5. Inspect the old spark plug for signs of wear (e.g., carbon buildup, damage).
6. Install a new spark plug, ensuring to use the correct gap specification.
7. Torque the spark plug to the manufacturer-recommended value (typically 22 Nm).

3. Replace Ignition Coil (if necessary)

1. If the ignition coil is faulty (as determined from diagnostic steps), disconnect the electrical connector from the coil.
2. Remove the screws or bolts securing the ignition coil and carefully pull it out.
3. Install the new ignition coil by reversing the removal steps and ensure it is properly seated.
4. Reconnect the electrical connector.

4. Check Fuel Injector

1. If the fuel injector is suspected to be faulty, locate the connector and carefully disconnect it.
2. Use a multimeter to test the resistance of the fuel injector; refer to manufacturer specifications for acceptable values.
3. If the injector is faulty, remove it from the intake manifold (may require additional components to be removed).
4. Install the new fuel injector, ensuring O-rings are lubricated and properly seated.