how to diagnose a P0301 code in my BMW 5 Series F10/F11 (2010-2017)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative terminal of the battery to ensure safety.
• Lift the vehicle using a jack and secure it on jack stands if necessary for better access.

2. Inspect Ignition Components

• Remove the ignition coil from cylinder 1:
  • Unscrew any fasteners securing the coil.
  • Carefully pull the coil out of the spark plug well.
• Inspect the coil for cracks or damage. If damaged, replace it.
• Remove the spark plug from cylinder 1 using a spark plug socket:
  • Check the spark plug for wear and fouling. Replace it if necessary (use OEM specifications for the spark plug gap).
  • Torque the new spark plug to 23 Nm (17 lb-ft).

3. Check Fuel Injector

• Disconnect the fuel injector connector for cylinder 1.
• Use a multimeter to ensure the injector is receiving the correct voltage:
  • If not, trace the wiring back to the engine control module (ECM).
• If the injector is faulty, remove it:
  • Use an injector puller, if necessary, and replace it with a new one.
• Reconnect the fuel injector connector.

4. Reassemble and Test

• Reinstall the ignition coil and secure it with the appropriate fasteners.
• Reconnect the negative terminal of the battery.
• Start the engine and let it idle to check for any misfires or issues.