how to fix P0301 misfire code in Volvo XC90 Second Generation (2015-2024)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety during repairs.

2. Inspect and Replace Spark Plug

• Tools Required: Spark plug socket, torque wrench.
• Remove the ignition coil cover if applicable.
• Disconnect the ignition coil connector and remove the ignition coil from cylinder 1.
• Remove the spark plug using a spark plug socket.
• Inspect the spark plug for wear or damage; replace it if necessary.
• Install the new spark plug and tighten it to the manufacturer’s specified torque (typically around 15-20 lb-ft).
• Reinstall the ignition coil and reconnect the connector.

3. Check and Replace Ignition Coil (if necessary)

• If the spark plug is in good condition but the misfire persists, test the ignition coil.
• Tools Required: Multimeter.
• Using a multimeter, check the primary and secondary resistance of the ignition coil.
• If the coil is faulty, replace it with a new one.
• Reinstall the ignition coil and reconnect the connector.

4. Inspect and Clean Fuel Injector

• If the issue remains unresolved, check the fuel injector for cylinder 1.
• Tools Required: Fuel injector cleaner or replacement injector.
• Remove the fuel rail (if necessary) to access the fuel injector.
• Test the fuel injector using a multimeter or injector tester.
• Clean the injector using a suitable cleaner, or replace it if it’s not functioning correctly.
• Reassemble the fuel rail and ensure all connections are secure.

5. Perform Compression Test

• If misfires continue, perform a compression test on cylinder 1.
• Tools Required: Compression gauge.
• Remove the spark plug from cylinder 1 and insert the compression gauge.
• Crank the engine and note the compression reading.
• Compare the reading to the manufacturer’s specifications; if low, further diagnostics may be needed for internal engine issues.