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How do I troubleshoot a Toyota Highlander with a malfunctioning headlight switch? - Toyota Highlander
Home/Cars/Toyota/Highlander/Fourth Generation (2020-present)/How do I troubleshoot a Toyota Highlander with a malfunctioning headlight switch?

How do I troubleshoot a Toyota Highlander with a malfunctioning headlight switch?

Toyota Highlander Fourth Generation (2020-present)

Error Codes
2-3 hours
Time
medium
Difficulty
medium
Severity
Navigation
ProblemSymptomsDiagnosisSolution
ProblemSymptomsDiagnosisSolution
4 min read
621 words

Problem Statement

Learn how to troubleshoot and fix a malfunctioning headlight switch on a 2020-present Toyota Highlander with step-by-step diagnostic steps and required tools.

Affected Component
headlight switch
Estimated Time
2-3 hours

Symptoms

  • •Headlights do not turn on or off.
  • •High beams do not function.
  • •Dashboard lights remain illuminated when headlights are off.
  • •Flickering or intermittent headlight operation.
  • •Error messages on the dashboard related to the lighting system.

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

  • •Multimeter
  • •Wiring Diagram
  • •Electrical Contact Cleaner
  • •Screwdriver Set
  • •Torque Wrench

Additional Information

Affected Component
headlight switch
Estimated Time
2-3 hours
Difficulty
medium
Severity
medium
Tools Required
5 items

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Back to Generation

Troubleshooting a Malfunctioning Headlight Switch on a 2020-Present Toyota Highlander (Fourth Generation, XU70)

Step 1: Visual Inspection

Tools Required: None

  1. Check Headlight Bulbs:

    • Inspect the headlight bulbs for any signs of burn-out or damage. Replace any malfunctioning bulbs.

  2. Examine the Fuses:

    • Locate the fuse box (usually under the dashboard or engine compartment).
    • Check the headlight fuse (refer to the owner’s manual for the exact location and fuse rating).
    • Replace any blown fuses and retest the headlights.
Step 2: Test the Headlight Switch

Tools Required: Multimeter, Wiring Diagram

  1. Access the Headlight Switch:

    • Remove the trim panel surrounding the steering column to access the headlight switch.
    • Disconnect the wiring harness connected to the switch.

  2. Check the Switch Operation:

    • Using a multimeter, set it to continuity mode.
    • Test the continuity of the switch when toggled between different positions (off, low beam, high beam).
    • Refer to the wiring diagram to identify which terminals correspond to each switch position.
    • If there is no continuity in the expected positions, the switch is faulty and needs replacement.
Step 3: Inspect Wiring and Connectors

Tools Required: Multimeter, Wiring Diagram, Electrical Contact Cleaner

  1. Visual Inspection of Wiring:

    • Inspect all wiring and connectors leading from the headlight switch to the headlights for any signs of damage, corrosion, or loose connections.
    • Clean any corroded connectors with electrical contact cleaner.

  2. Check Voltage at the Headlight Connector:

    • Reconnect the wiring harness to the headlight switch.
    • With the headlights in the on position, use the multimeter to check for voltage at the headlight connectors.
    • If there is no voltage present, the issue may lie further down the circuit.
Step 4: Check Headlight Relay

Tools Required: Multimeter, Wiring Diagram

  1. Locate the Headlight Relay:

    • Find the headlight relay in the fuse box (consult the owner’s manual for the exact location).

  2. Test the Relay:

    • Remove the relay and test it using the multimeter for continuity and operation (following the relay testing procedure).
    • If the relay is faulty, replace it.
Step 5: Replace the Headlight Switch

Tools Required: Screwdriver Set, Torque Wrench (if specified)

  1. Purchase Replacement Part:

    • Acquire a new headlight switch compatible with the 2020-present Toyota Highlander.

  2. Remove the Old Switch:

    • Disconnect the battery to avoid any electrical shorts.
    • Remove the trim panel again if it was not removed previously.
    • Unscrew the headlight switch from its mounting location.
    • Disconnect the wiring harness from the old switch.

  3. Install the New Switch:

    • Connect the wiring harness to the new headlight switch.
    • Secure the switch in its mounting location.
    • Reattach the trim panel.

  4. Reconnect Battery:

    • Reconnect the battery and test the new headlight switch functionality.
Final Check

  1. Test all Headlight Functions:

    • Turn on the vehicle and test low beams, high beams, and dashboard light functionality.
    • Verify that all settings (off, parking lights, low beams, high beams) work as intended.

  2. Recheck Fuses and Relays:

    • Ensure all previously checked fuses and relays are properly seated and functioning.

By following these steps, you should be able to diagnose and resolve issues related to a malfunctioning headlight switch on a 2020-present Toyota Highlander. Always refer to the vehicle’s service manual for specific details and torque specifications.