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why is my Toyota Highlander Third Generation (2014-2019) check engine light on - Toyota Highlander
Home/Cars/Toyota/Highlander/Third Generation (2014-2019)/why is my Toyota Highlander Third Generation (2014-2019) check engine light on

why is my Toyota Highlander Third Generation (2014-2019) check engine light on

Toyota Highlander Third Generation (2014-2019)

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

Problem Statement

Learn how to diagnose and fix the check engine light issue in a 2014-2019 Toyota Highlander. Step-by-step guide with diagnostic procedures and repair instructions.

Affected Component
Engine
Estimated Time
1-3 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

  • •Disconnect the battery before working on electrical systems.
  • •Allow the engine to cool before starting any maintenance or repair work.

Symptoms

  • •Check engine light illuminated
  • •Decreased fuel efficiency
  • •Rough idling or engine misfires
  • •Loss of power during acceleration
  • •Unusual engine noises
  • •Increased 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
  • •Fuel pressure gauge
  • •MAF cleaner spray

Parts Required

  • •Spark plugs
  • •Ignition coils (if necessary)
  • •Gas cap (if damaged)
  • •Fuel filter (if necessary)

Additional Information

Affected Component
Engine
Estimated Time
1-3 hours
Difficulty
medium
Severity
medium
Tools Required
6 items
Parts Required
4 items

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Solution
1. Preparation
  • Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, fuel pressure gauge.
  • Disconnect the battery to ensure safety while working on electrical components.
2. Addressing Common Issues

A. Tighten or Replace Gas Cap

  • Inspect the gas cap for cracks or damage.
  • If the gas cap is loose, ensure it is tightened securely.
  • If damaged, replace with a new gas cap.

B. Replace Spark Plugs and Ignition Coils

  • Remove the engine cover if necessary.
  • Disconnect the ignition coil connectors.
  • Unscrew and remove the ignition coils using a socket set.
  • Remove the old spark plugs using a spark plug socket.
  • Install new spark plugs, ensuring they are gapped correctly (typically around 0.044 inches).
  • Reinstall the ignition coils and connectors.

C. Inspect and Clean MAF Sensor

  • Locate the Mass Air Flow (MAF) sensor.
  • Disconnect the electrical connector.
  • Remove the MAF sensor using a socket set.
  • Clean the MAF sensor with MAF cleaner spray and allow it to dry.
  • Reinstall the sensor and reconnect the electrical connector.

D. Check Fuel System

  • Connect the fuel pressure gauge to the fuel rail.
  • Turn the ignition to the "ON" position (do not start the engine).
  • Check the gauge reading against manufacturer specifications (usually around 50-60 psi).
  • If low, inspect the fuel pump and fuel filter for issues.
3. Reset Check Engine Light
  • Reconnect the battery.
  • Use the OBD-II scanner to clear the trouble codes and reset the check engine light.