FAULTBASE
Error CodesASKCars
© 2026 FAULTBASE
All rights reserved.
v2.0.0 • Production
ContactPrivacyImpressum
How can I troubleshoot a malfunctioning key fob for my 2020 Highlander? - Toyota Highlander
Home/Cars/Toyota/Highlander/Fourth Generation (2020-present)/How can I troubleshoot a malfunctioning key fob for my 2020 Highlander?

How can I troubleshoot a malfunctioning key fob for my 2020 Highlander?

Toyota Highlander Fourth Generation (2020-present)

Error Codes
1-2 hours
Time
medium
Difficulty
medium
Severity
Navigation
ProblemSymptomsDiagnosisSolution
ProblemSymptomsDiagnosisSolution
3 min read
497 words

Problem Statement

Learn how to troubleshoot and fix issues with the key fob of your 2020 Toyota Highlander, including symptoms, diagnostic steps, and repair instructions.

Affected Component
key fob
Estimated Time
1-2 hours

Symptoms

  • •Unresponsive Lock/Unlock Functions
  • •No Remote Start
  • •Range Issues
  • •Warning Lights

Diagnostic Steps

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

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

  • •Small Phillips screwdriver
  • •multimeter (optional)
  • •OBD-II Scanner

Additional Information

Affected Component
key fob
Estimated Time
1-2 hours
Difficulty
medium
Severity
medium
Tools Required
3 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

Troubleshooting a Malfunctioning Key Fob for a 2020 Toyota Highlander

Step 1: Visual Inspection
  • Check for Physical Damage: Inspect the key fob for cracks, broken buttons, or water damage.
  • Battery Compartment: Open the key fob and check for corrosion in the battery compartment.
Step 2: Battery Check
  • Tools Required: Small Phillips screwdriver, multimeter (optional).
  • Battery Replacement:
    1. Use the screwdriver to remove the back cover of the key fob.
    2. Remove the old battery (typically CR2032 or CR2025).
    3. Check the battery voltage with a multimeter; it should read 3V.
    4. Replace with a new battery, ensuring correct polarity (+/-).
    5. Reassemble the key fob and test its functionality.
Step 3: Frequency Interference
  • Tools Required: None.
  • Check for Interference: Move to a different location away from electronic devices (e.g., Wi-Fi routers, cell phones) and test the fob again.
Step 4: Reprogramming the Key Fob
  • Tools Required: None for basic reprogramming, but a scan tool may be needed for advanced diagnostics.
  • Reprogramming Steps:
    1. Enter the vehicle with all doors closed.
    2. Insert the key into the ignition and turn it to the "ON" position (do not start).
    3. Press the "Lock" button on the key fob once.
    4. Turn the ignition key to "OFF" and remove it.
    5. Test the key fob to see if it works.
Step 5: Diagnostic Scan
  • Tools Required: OBD-II Scanner.
  • Diagnostic Steps:
    1. Connect the OBD-II scanner to the vehicle's port (typically under the dashboard).
    2. Turn the ignition to the "ON" position without starting the engine.
    3. Scan for error codes related to the key fob or immobilizer system.
    4. Record any trouble codes for further investigation.
Repair Instructions
If Key Fob is Non-Repairable

  1. Order a Replacement Key Fob:

    • Contact a Toyota dealership or authorized service center for a replacement key fob.
    • Provide the Vehicle Identification Number (VIN) for programming.

  2. Programming the New Key Fob:

    • Follow the same reprogramming steps as outlined in Step 4.
    • If the fob requires dealer programming, schedule an appointment.
If Key Fob Works Intermittently
  • Check for Loose Connections: Open the fob again and ensure all connections are secure.
  • Clean Contacts: Use electronic contact cleaner on the circuit board and battery contacts.
Conclusion

By following these detailed steps, you can troubleshoot and potentially resolve issues with a malfunctioning key fob on your 2020 Toyota Highlander. If issues persist after testing the battery, checking for interference, and reprogramming, a professional diagnosis may be necessary.