why does my Toyota Highlander XU70 (2020-Present) check engine light stay on after refueling

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is off.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Fuel Filler Cap

• Remove the fuel filler cap.
• Inspect the cap for cracks, wear, or a damaged gasket.
• If damaged, replace with a new fuel filler cap.
• Reinstall the cap securely.

3. Check EVAP System Components

• Locate the EVAP canister and inspect for cracks or damage.
• Check the connecting hoses for any signs of wear, tears, or blockages.
• Replace any damaged hoses or components as needed.

4. Test and Repair Fuel System

• Connect a fuel pressure gauge to the fuel rail.
• Start the engine and observe the fuel pressure reading; it should meet manufacturer's specifications (usually around 30-50 psi).
• If the pressure is low, inspect the fuel pump and replace if necessary.

5. Clear Codes and Reconnect Battery

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear any error codes.
• Start the engine and observe if the check engine light remains off.