FAULTBASE
Error CodesASKCars
© 2026 FAULTBASE
All rights reserved.
v2.0.0 • Production
ContactPrivacyImpressum
what causes the check engine light to come on in Toyota Highlander XU70 (2020-Present) - Toyota Highlander
Home/Cars/Toyota/Highlander/XU70 (2020-Present)/what causes the check engine light to come on in Toyota Highlander XU70 (2020-Present)

what causes the check engine light to come on in Toyota Highlander XU70 (2020-Present)

Toyota Highlander XU70 (2020-Present)

Error Codes
2-4 hours
Time
medium
Difficulty
medium
Severity
Navigation
ProblemSymptomsDiagnosisSolution
ProblemSymptomsDiagnosisSolution
4 min read
607 words

Problem Statement

Discover the causes of the check engine light in the 2020-Present Toyota Highlander XU70. Follow our diagnostic steps and solutions for effective repairs.

Affected Component
Engine
Estimated Time
2-4 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

  • •Disconnect the battery before working on electrical systems.
  • •Allow the engine to cool before inspecting components to prevent burns.

Symptoms

  • •Check engine light illuminated on the dashboard
  • •Decreased engine performance or acceleration
  • •Rough idle or stalling while idling
  • •Poor fuel economy
  • •Unusual noises from the engine
  • •Increased exhaust emissions

Diagnostic Steps

  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6

Solution

💡 Expert Tip

For complex repairs like this, consider taking photos at each step. This helps if you need to reverse a step or consult with a mechanic. Also, keep all removed parts organized - you may need to reference them during reassembly.

Verification

After completing the repair, verify that the issue has been resolved:

  • ✓Test the affected component to ensure it functions correctly
  • ✓Check for any error codes or warning lights
  • ✓Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

  • •Follow the manufacturer's recommended maintenance schedule
  • •Address warning signs early before they develop into major issues
  • •Use quality parts and fluids recommended for your vehicle
  • •Keep detailed records of all repairs and maintenance

Tools & Equipment Required

  • •OBD-II scanner
  • •Socket set
  • •Torque wrench
  • •Multimeter
  • •Smoke machine (optional)

Parts Required

  • •New gas cap (if needed)
  • •Spark plugs
  • •Ignition coils (if needed)
  • •Oxygen sensors (if needed)
  • •Vacuum hoses (if needed)

Additional Information

Affected Component
Engine
Estimated Time
2-4 hours
Difficulty
medium
Severity
medium
Tools Required
5 items
Parts Required
5 items

Related Faults

Loading...

Share this solution

Comments

Sign in to share your thoughts

Sign In

No comments yet

Be the first to share your thoughts

Back to Generation
Solution
1. Preparation
  • Gather necessary tools and parts.
  • Ensure the vehicle is parked on a flat surface and the engine is cool.
  • Disconnect the battery to prevent any electrical shorts during diagnostics.
2. Check and Replace the Gas Cap
  • Inspect the gas cap for cracks or damage.
  • If necessary, replace the gas cap with a new one.
  • Tighten the new gas cap until it clicks to ensure a proper seal.
3. Inspect and Replace Spark Plugs
  • Remove the ignition coil cover (if applicable) using a socket set.
  • Disconnect the ignition coils from the spark plugs.
  • Remove old spark plugs using a spark plug socket.
  • Check the gap on the new spark plugs and install them according to manufacturer specifications (usually around 0.044 inches).
  • Reinstall the ignition coils and cover.
4. Test and Replace Oxygen Sensors
  • Locate the upstream and downstream oxygen sensors on the exhaust system.
  • Disconnect the wiring harness from each sensor.
  • Use a multimeter to test the resistance and output voltage of the sensors (specifications can be found in the service manual).
  • Replace faulty sensors with new ones, ensuring proper torque (typically around 30 ft-lbs).
5. Inspect and Repair Vacuum Leaks
  • Perform a visual inspection of all vacuum hoses for cracks or disconnections.
  • Use a smoke machine or carburetor cleaner to identify leaks while the engine is running.
  • Replace or repair any damaged hoses.
6. Testing the Catalytic Converter
  • Use a backpressure gauge to measure exhaust backpressure.
  • If backpressure exceeds manufacturer specifications (usually around 1.5 psi at idle), consider replacing the catalytic converter.