how to fix P0301 misfire code on BMW X5 G05 (2019-2024)

Solution

1. Preparation

• Gather tools and parts needed.
• Disconnect the negative battery terminal to ensure safety.
• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, compression tester.

2. Inspect and Replace Ignition Components

• Remove the engine cover (if applicable).
• Disconnect the electrical connector from the ignition coil for cylinder 1.
• Remove the ignition coil by unscrewing the retaining bolt and pulling it out gently.
• Inspect the spark plug in cylinder 1: remove it using a spark plug socket and check for wear or deposits.
• Replace the spark plug and ignition coil with new OEM parts.
  • Torque the spark plug to the manufacturer’s specification (usually around 15-20 ft-lbs).
• Reconnect the ignition coil and ensure it’s seated properly.

3. Check Fuel Injector

• Disconnect the fuel injector connector for cylinder 1.
• Use a multimeter to check the injector's resistance; compare it to the manufacturer’s specifications.
• If the injector is faulty, remove it (by unscrewing or unclipping, depending on the design) and replace it with a new one.
• Reconnect the fuel injector and ensure it is properly seated.

4. Perform Compression Test

• Remove the spark plug for cylinder 1 to access the cylinder.
• Insert the compression tester into the spark plug hole.
• Crank the engine for several seconds and record the reading.
• Compare the result to the manufacturer’s specifications for acceptable compression levels.
• If compression is low, further investigation into internal engine issues may be required.

5. Reassemble and Clear Codes

• Replace any other components that were removed during inspection.
• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0301 code from the system.
• Start the engine and allow it to idle to ensure smooth operation.