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

Solution

1. Preparation

• Gather tools: OBD-II scanner, multimeter, spark plug socket, compression gauge, basic hand tools.
• Disconnect the battery to ensure safety while working on electrical components.

2. Replace Spark Plug

1. Remove the engine cover if necessary to access the ignition components.
2. Use a spark plug socket to carefully remove the spark plug from cylinder 1.
3. Inspect the old spark plug for signs of wear, fouling, or damage.
4. Install a new spark plug (OEM recommended type) to the specified torque (typically around 20 Nm).
5. Reattach any components removed for access.

3. Replace Ignition Coil

1. Disconnect the electrical connector from the ignition coil for cylinder 1.
2. Remove any retaining bolts and lift out the ignition coil.
3. Install the new ignition coil, ensuring it is seated correctly.
4. Reconnect the electrical connector and secure with bolts.

4. Inspect and Clean Fuel Injector

1. Disconnect the fuel injector connector for cylinder 1.
2. Remove the fuel rail if required to access the injector.
3. Inspect the fuel injector for clogs or leaks.
4. Clean the injector with an appropriate cleaner or replace it if necessary.
5. Reassemble the fuel rail and reconnect all components.

5. Compression Test

1. Remove the spark plug from cylinder 1 again for access.
2. Insert the compression gauge into the spark plug hole.
3. Crank the engine for a few seconds to obtain a reading.
4. Compare the compression reading to the manufacturer specifications (usually between 130-200 psi).
5. If compression is low, further investigation is required, potentially leading to a valve or piston issue.