how to fix P0303 code in BMW X3 G01 (2018-2024)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool before starting the work.

2. Replace Spark Plug and Ignition Coil

1. Remove Engine Cover:

   • Use a socket set to remove fasteners securing the engine cover.
   • Carefully lift off the cover and set aside.

2. Remove Ignition Coil:

   • Disconnect the electrical connector from the ignition coil on cylinder 3.
   • Unscrew the ignition coil using the appropriate socket.
   • Pull the ignition coil straight out of the cylinder head.

3. Replace Spark Plug:

   • Use a spark plug socket to remove the old spark plug from cylinder 3.
   • Inspect the spark plug for wear; replace if necessary.
   • Apply anti-seize compound on the threads of the new spark plug.
   • Install the new spark plug and tighten to manufacturer specifications (around 22 Nm).

4. Install New Ignition Coil:

   • Insert the new ignition coil into the cylinder head.
   • Secure it with screws and reconnect the electrical connector.

3. Inspect and Replace Fuel Injector (if necessary)

1. Remove Fuel Rail:

   • Relieve fuel pressure by removing the fuel pump fuse and running the engine until it stalls.
   • Disconnect the fuel line and remove the fuel rail bolts.
   • Carefully lift the fuel rail to access the injectors.

2. Replace Injector:

   • Pull out the old injector and replace it with a new one.
   • Ensure proper seating and reconnect the fuel line.

3. Reassemble Fuel Rail:

   • Reinstall the fuel rail, securing it with bolts.
   • Reconnect the fuel pump fuse and check for leaks.

4. Clear Codes and Test

1. Reconnecting Battery:

   • Reconnect the negative battery terminal.

2. Scan for Codes:

   • Use an OBD-II scanner to clear the P0303 code and any other codes.
   • Start the engine and verify that the check engine light is off.