how to fix P0303 code in Volkswagen Golf Seventh Generation (2013-2020)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, spark plug socket, compression gauge, multimeter.
• Park the vehicle on a level surface and engage the parking brake.
• Disconnect the battery to ensure safety during repairs.

2. Replace Spark Plug and Ignition Coil

• Remove the engine cover if applicable.
• Locate the ignition coil for cylinder 3 (refer to the vehicle's service manual for cylinder numbering).
• Remove the electrical connector from the ignition coil.
• Using a socket set, remove the ignition coil bolts and pull the coil out.
• Remove the spark plug using a spark plug socket. Inspect the old spark plug for wear; replace it if necessary.
• Install the new spark plug to the manufacturer’s specified torque (usually around 25 Nm).
• Insert the new ignition coil and secure it with bolts, then reconnect the electrical connector.

3. Inspect and Replace Fuel Injector (if necessary)

• If the injector is suspected to be faulty, disconnect the fuel line and electrical connector from the injector.
• Remove the fuel injector retaining clips and pull the injector out.
• Inspect the injector for clogs or damage; replace if necessary.
• Install the new injector and ensure it is seated properly, reattach the fuel line and connector.

4. Compression Test

• Remove the spark plug from cylinder 3 and install the compression gauge.
• Crank the engine several times and record the compression reading.
• If the compression is below the manufacturer's specification (usually around 120-150 psi), further investigation into the engine's internals may be required.

5. Reassemble and Reconnect Battery

• Reinstall any components that were removed during the repair.
• Reconnect the battery terminals securely.