my Volvo XC90 Second Generation (2015-2024) has a check engine light and a P0301 code what's wrong

Solution

1. Preparation

• Gather required tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Spark Plug

• Sub-steps:
  1. Locate the spark plug for cylinder 1 (usually accessible from the engine cover).
  2. Remove the ignition coil by unscrewing the bolts and disconnecting the electrical connector.
  3. Remove the spark plug using a spark plug socket and ratchet.
  4. Inspect the spark plug for wear (fouling, cracking) and replace if necessary.
  5. Gap the new spark plug to manufacturer specifications (usually around 0.028-0.031 inches).
  6. Install the new spark plug and reattach the ignition coil, ensuring proper torque (typically around 15 ft-lbs).

3. Inspect and Replace Ignition Coil (if needed)

• Sub-steps:
  1. If the spark plug replacement does not resolve the issue, inspect the ignition coil visually for cracks or damage.
  2. Test the ignition coil's resistance with a multimeter (consult specifications for proper values).
  3. Remove the faulty ignition coil and install a new one, ensuring it’s properly seated.
  4. Reconnect the electrical connector and test for proper operation.

4. Check Fuel Injector Operation

• Sub-steps:
  1. Locate the fuel injector for cylinder 1 and disconnect the electrical connector.
  2. Use a noid light to check for injector pulse; if no pulse, inspect wiring and ECM.
  3. If the injector is faulty, remove it and install a new one, ensuring to replace any O-rings.
  4. Reconnect the electrical connector and test drive the vehicle.