what does it mean if my Toyota Highlander’s check engine light is on

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface with the engine off.
• Disconnect the battery before working on electrical systems.

2. Address OBD-II Codes

• Connect the OBD-II scanner to the vehicle's diagnostic port.
• Retrieve and record error codes.
• Research the codes to determine the specific issues (e.g., P0300 for random misfire).

3. Repair Specific Issues

• For Loose Gas Cap:

  • Tighten the gas cap until it clicks.

• For Spark Plugs/Ignition Coils:

  • Remove the ignition coil or spark plug.
  • Inspect for wear; replace if necessary.
  • Reinstall using a torque wrench to the manufacturer’s specifications (typically around 13 ft-lbs for spark plugs).

• For Electrical Issues:

  • Repair or replace any damaged wiring or connectors.
  • Ensure all connections are secure.

4. Clear Error Codes

• After completing repairs, reconnect the OBD-II scanner.
• Use the scanner to clear the error codes.

5. Reconnect Battery

• Reconnect the battery terminals and ensure they are tight.