my BMW 5 Series F10/F11 (2010-2017) has a P0303 code what does this mean

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, compression tester, fuel injector cleaner.
• Disconnect the negative battery terminal to ensure safety while working on the vehicle.

2. Inspect and Replace Spark Plug

1. Remove the engine cover (if applicable) to access the ignition components.
2. Use a socket set to remove the spark plug from cylinder 3.
3. Inspect the spark plug for signs of wear, fouling, or damage.
4. If necessary, replace the spark plug with a new OEM or high-quality aftermarket part.
5. Torque the new spark plug to the manufacturer's specification (usually around 13 lb-ft).

3. Check and Replace Ignition Coil

1. Disconnect the ignition coil connector for cylinder 3.
2. Remove the ignition coil using a socket set.
3. Test the ignition coil with a multimeter for proper resistance (specifications can vary; consult the service manual).
4. If the coil is faulty, replace it with a new one.
5. Reinstall the ignition coil and reconnect the connector.

4. Fuel Injector Cleaning or Replacement

1. Disconnect the fuel injector connector for cylinder 3.
2. Remove the fuel rail if required to access the injector.
3. Inspect the injector for clogs or damage. If clogged, clean with a fuel injector cleaner or replace if necessary.
4. Reinstall the injector and reconnect the fuel rail, ensuring proper sealing.

5. Compression Test

1. Remove the spark plug from cylinder 3 again.
2. Insert the compression tester into the spark plug hole.
3. Crank the engine and record the compression reading.
4. Compare the compression value with the manufacturer's specifications. If low, further diagnostics on the engine internals may be necessary.