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

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, compression tester, fuel injector cleaner.
• Ensure the engine is cool before starting.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Replace Spark Plug

• Remove the engine cover if necessary.
• Remove the ignition coil for cylinder 1 by unbolting it and disconnecting the electrical connector.
• Unscrew and remove the old spark plug using a spark plug socket.
• Inspect the spark plug gap and replace it with a new spark plug that meets factory specifications.
• Reinstall the ignition coil, ensuring it is seated properly.

3. Test and Replace Ignition Coil (if necessary)

• Use a multimeter to measure the resistance of the ignition coil (specifications can be found in the service manual).
• If the ignition coil is faulty, replace it with a new one.
• Reconnect the ignition coil and ensure all connections are secure.

4. Perform Compression Test

• Insert the compression tester into the spark plug hole of cylinder 1.
• Crank the engine and record the compression reading.
• Compare the reading to manufacturer specifications. If low, further investigation into the engine internals may be necessary.

5. Inspect and Clean Fuel Injector

• Remove the fuel injector from cylinder 1 after relieving fuel pressure.
• Inspect for clogs or damage. Use fuel injector cleaner to clean the injector if it appears dirty.
• Reinstall the fuel injector ensuring it is seated properly.