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

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, compression tester, basic hand tools.
• Disconnect the negative battery terminal to ensure safety.
• Gather necessary replacement parts if needed (spark plugs, ignition coil, etc.).

2. Inspect and Replace Spark Plug

• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Locate the spark plug for Cylinder 1 (check the vehicle's service manual for location).
  3. Using a socket wrench, remove the spark plug by turning counterclockwise.
  4. Inspect the spark plug for wear (look for carbon buildup, damage, or incorrect gap).
  5. If necessary, replace the spark plug with a new one, ensuring it is gapped correctly according to specifications.
  6. Reinstall the spark plug and torque it to the manufacturer's specifications (usually around 15-20 Nm).

3. Inspect and Replace Ignition Coil

• Sub-steps:
  1. Remove the ignition coil connector by pressing the tab and pulling it out.
  2. Unbolt the coil from the engine block (usually one or two screws).
  3. Inspect the ignition coil for cracks or signs of wear.
  4. If faulty, replace it with a new ignition coil, ensuring it matches the specifications.
  5. Reinstall the ignition coil and reconnect the electrical connector.

4. Fuel Injector Inspection

• Sub-steps:
  1. Locate the fuel injector for Cylinder 1.
  2. Check the injector connector for secure connection and signs of wear.
  3. If necessary, test the injector using a multimeter to ensure it is receiving the correct voltage.
  4. If the injector is faulty, replace it with a new one, ensuring proper sealing to prevent leaks.

5. Compression Test

• Sub-steps:
  1. Remove the spark plug for Cylinder 1 again.
  2. Insert the compression tester into the spark plug hole.
  3. Crank the engine for several seconds and record the compression reading.
  4. Compare the reading to the manufacturer's specifications.
  5. If compression is low, further diagnosis may be needed (e.g., valve issues, head gasket failure).