why does my Toyota Highlander XU70 (2020-Present) check engine light keep coming on

Solution

1. Preparation

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

2. Scan and Identify

• Connect the OBD-II scanner to the vehicle's diagnostic port.
• Record any error codes displayed and refer to the service manual for interpretations.

3. Address Engine Oil Issues

• Remove the oil dipstick and check the oil level; add oil if low.
• If oil is dirty or contaminated, perform an oil change:
  • Drain the old oil using an oil drain pan.
  • Replace the oil filter using an oil filter wrench.
  • Refill with the manufacturer-recommended oil (usually 0W-20).

4. Inspect and Repair Vacuum Leaks

• Visually inspect all vacuum hoses for cracks or disconnections.
• Replace any damaged hoses and ensure all connections are secure.

5. Test and Clean the MAF Sensor

• Disconnect the MAF sensor's electrical connector.
• Remove the sensor and clean it with MAF cleaner spray (do not touch the sensing elements).
• Reinstall the sensor and reconnect the electrical connector.

6. Check the Fuel System

• Use a fuel pressure gauge to test the fuel pressure at the rail.
• If pressure is low, check the fuel pump and replace if necessary.

7. Inspect the Catalytic Converter

• Check for any unusual noises or signs of overheating from the catalytic converter.
• If blocked, replace the catalytic converter following manufacturer specifications.