FAULTBASE
Error CodesASKCars
© 2026 FAULTBASE
All rights reserved.
v2.0.0 • Production
ContactPrivacyImpressum
What are the signs of a failing ignition coil in a Toyota Highlander? - Toyota Highlander
Home/Cars/Toyota/Highlander/Fourth Generation (2020-present)/What are the signs of a failing ignition coil in a Toyota Highlander?

What are the signs of a failing ignition coil in a Toyota Highlander?

Toyota Highlander Fourth Generation (2020-present)

Error Codes
1-2 hours
Time
medium
Difficulty
medium
Severity
Navigation
ProblemSymptomsDiagnosisSolution
ProblemSymptomsDiagnosisSolution
4 min read
677 words

Problem Statement

Learn about the symptoms, diagnostic steps, and repair instructions for a failing ignition coil in a Toyota Highlander (2020-present).

Affected Component
ignition coil
Estimated Time
1-2 hours

Symptoms

  • •Engine Misfire
  • •Check Engine Light
  • •Poor Fuel Economy
  • •Rough Idle
  • •Difficulty Starting
  • •Increased Emissions

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

  • •OBD-II Scanner
  • •Multimeter
  • •Socket set
  • •Torque wrench
  • •Ratchet and extensions
  • •Safety gloves and goggles

Additional Information

Affected Component
ignition coil
Estimated Time
1-2 hours
Difficulty
medium
Severity
medium
Tools Required
6 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

Signs of a Failing Ignition Coil in a Toyota Highlander (2020-Present)

Tools Required
  • OBD-II Scanner
  • Multimeter
  • Socket set (for removing ignition coils and spark plugs)
  • Torque wrench
  • Ratchet and extensions
  • Safety gloves and goggles
Repair Instructions
Replacing the Ignition Coil

  1. Preparation

    • Park the vehicle on a flat surface and engage the parking brake.
    • Disconnect the negative battery terminal to prevent electrical shock.

  2. Remove Engine Cover (if applicable)

    • Use the appropriate socket to remove any bolts securing the engine cover.
    • Set the cover aside.

  3. Access the Ignition Coil

    • Locate the ignition coils on the engine.
    • Identify the coil that needs replacement based on the symptoms and diagnostic steps.

  4. Disconnect the Ignition Coil

    • Carefully unplug the electrical connector from the ignition coil by pressing the release tab and pulling it out.

  5. Remove the Ignition Coil

    • Unscrew the ignition coil mounting bolt(s) using the appropriate socket.
    • Pull the ignition coil out of the spark plug well.

  6. Install the New Ignition Coil

    • Insert the new ignition coil into the spark plug well.
    • Secure it with the mounting bolt(s) and tighten to the manufacturer's specifications (usually around 7-10 Nm).

  7. Reconnect the Electrical Connector

    • Attach the ignition coil connector securely until you hear a click.

  8. Reinstall Engine Cover (if applicable)

    • Replace the engine cover and secure it with the appropriate bolts.

  9. Reconnect the Battery

    • Reattach the negative battery terminal and ensure it is tight.

  10. Clear DTCs and Test Drive

    • Use the OBD-II scanner to clear any stored trouble codes.
    • Start the engine and allow it to idle, then take the vehicle for a test drive to ensure the issue is resolved.
Post-Replacement Checks
  • Monitor for any reoccurrence of symptoms.
  • Check for new DTCs after driving for a short distance.
Conclusion

If the symptoms persist after replacing the ignition coil, further diagnostics may be required, including checking the engine control unit (ECU), spark plugs, or fuel delivery system. Always refer to the vehicle’s service manual for specific torque specifications and detailed repair procedures.