how to fix P0303 code in my BMW 5 Series F10/F11 (2010-2017)

Solution

1. Preparation

• Gather tools and materials before starting the repair.
• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, compression tester, and fuel injector cleaning kit.
• Safety Warnings: Disconnect the battery before working on electrical components.

2. Replace Spark Plug

• Sub-steps:
  1. Remove the engine cover (if applicable) using a socket set.
  2. Disconnect the ignition coil connector from the spark plug in cylinder 3.
  3. Remove the ignition coil using a socket set and inspect it for damage.
  4. Remove the spark plug using a spark plug socket and check for wear or fouling.
  5. Install a new spark plug with the correct gap (typically 0.032 inches for BMW).
  6. Reinstall the ignition coil and connect the wiring harness.

3. Replace Ignition Coil

• Sub-steps:
  1. If the ignition coil is found faulty during inspection, remove it from cylinder 3.
  2. Install a new ignition coil, ensuring it is seated properly.
  3. Reconnect the ignition coil electrical connector.

4. Clean or Replace Fuel Injector

• Sub-steps:
  1. If the fuel injector is not functioning, remove it by disconnecting the fuel line and electrical connector.
  2. Use a fuel injector cleaning kit to clean the injector, or replace it with a new one.
  3. Reinstall the fuel injector and reconnect the fuel line and electrical connector.

5. Reassemble and Test

• Sub-steps:
  1. Reattach any components removed during the repair process.
  2. Reconnect the battery.
  3. Start the engine and let it idle to check for any error codes.