how to troubleshoot P0303 code in Volvo XC60 Second Generation (2018-2024)

Learn how to troubleshoot and fix P0303 cylinder 3 misfire in Volvo XC60 (2018-2024). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool if it has been running.

2. Inspect and Replace Spark Plug

• Tools Required: Spark plug socket, ratchet, torque wrench
• Remove the ignition coil cover if necessary.
• Carefully remove the spark plug from cylinder 3 using a spark plug socket.
• Inspect the spark plug for signs of wear, such as excessive carbon buildup or damage.
• If necessary, replace the spark plug with a new one, ensuring it is gapped correctly per manufacturer specifications (0.028-0.031 inches for most Volvo engines).
• Reinstall the ignition coil and cover.

3. Test and Replace Ignition Coil

• If the spark plug is fine, test the ignition coil for cylinder 3 using a multimeter.
• Tools Required: Multimeter
• Set the multimeter to the resistance setting and measure the resistance.
• If the resistance is out of the specified range (consult service manual for exact values), replace the ignition coil with a new one.
• Reinstall the ignition coil after testing or replacement.

4. Compression Test

• Tools Required: Compression tester
• Remove the spark plug from cylinder 3.
• Attach the compression tester to the spark plug hole and crank the engine.
• Note the reading; it should be within the manufacturer’s specified range.
• If the reading is low, further investigation into the piston, rings, or valves may be required.

5. Inspect Fuel Injector

• Remove and inspect the fuel injector for cylinder 3 for clogs or faults.
• Tools Required: Fuel injector puller, multimeter (for testing)
• Clean or replace the fuel injector if necessary.
• Ensure proper seating and connections when reinstalling.

6. Check for Vacuum Leaks

• Inspect all vacuum hoses and connections around the intake manifold for cracks or disconnections.
• Use a smoke machine or carb cleaner to identify any leaks while the engine is running.
• Repair any leaks discovered.