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What are the symptoms of a failing ignition coil in a 2020 Toyota Highlander? - Toyota Highlander
Home/Cars/Toyota/Highlander/Fourth Generation (2020-present)/What are the symptoms of a failing ignition coil in a 2020 Toyota Highlander?

What are the symptoms of a failing ignition coil in a 2020 Toyota Highlander?

Toyota Highlander Fourth Generation (2020-present)

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

Problem Statement

Learn about the symptoms of a failing ignition coil in a 2020 Toyota Highlander, diagnostic steps, tools required, and repair instructions.

Affected Component
ignition coil
Estimated Time
2-3 hours

Symptoms

  • •Engine Misfires
  • •Decreased Engine Performance
  • •Poor Fuel Economy
  • •Rough Idling
  • •Check Engine Light
  • •Difficulty Starting
  • •Backfiring

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

  • •Basic hand tools (screwdrivers, socket set)
  • •Flashlight
  • •OBD-II scanner
  • •Multimeter
  • •Spark tester
  • •Socket set
  • •Torque wrench
  • •Ratchet
  • •Pliers
  • •Dielectric grease
  • •Clean cloth

Additional Information

Affected Component
ignition coil
Estimated Time
2-3 hours
Difficulty
medium
Severity
medium
Tools Required
11 items

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Repair Instructions

If the ignition coil is confirmed to be faulty, follow these steps for replacement:

  1. Gather Tools and Parts:

    • Tools Required: Socket set, torque wrench, ratchet, pliers, dielectric grease, clean cloth.
    • Purchase a replacement ignition coil (ensure it is compatible with the 2020 Toyota Highlander).

  2. Disconnect the Battery:

    • Using a wrench, disconnect the negative terminal of the battery to prevent any electrical shorts.

  3. Access the Ignition Coil:

    • Depending on the engine configuration, you may need to remove engine covers or components to access the ignition coils.
    • Locate the ignition coil(s) on the engine.

  4. Remove the Faulty Ignition Coil:

    • Disconnect the electrical connector from the ignition coil.
    • Remove the bolt(s) securing the coil to the engine using the socket set.
    • Carefully pull the ignition coil out of the spark plug well.

  5. Install the New Ignition Coil:

    • Apply a small amount of dielectric grease to the rubber boot of the new ignition coil.
    • Insert the new ignition coil into the spark plug well and secure it with the bolt(s).
    • Reconnect the electrical connector until it clicks into place.

  6. Reassemble and Test:

    • Reinstall any components or covers that were removed.
    • Reconnect the negative battery terminal.
    • Start the engine and monitor for any signs of misfire or performance issues.
    • Use the OBD-II scanner to check if any trouble codes return.
Final Note

If symptoms persist after replacing the ignition coil, further diagnosis may be required to check for additional issues such as a faulty spark plug, fuel injector issues, or problems with the engine control module (ECM). Always refer to the manufacturer’s service manual for specific torque specifications and additional repair procedures.