how to fix my Toyota Highlander Third Generation (2014-2019) that has a check engine light and runs...

Toyota Highlander Third Generation (2014-2019)

Error Codes

2-4 hours

Time

medium

Difficulty

high

Severity

3 min read

591 words

⚠️ Safety Warning

This issue requires immediate attention. If you are not experienced with automotive repairs, consult a professional mechanic. Working on critical systems can be dangerous.

Problem Statement

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

Affected Component

Engine

Estimated Time

2-4 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

•Disconnect the battery before working on electrical components.
•Allow the engine to cool before opening any components.

Symptoms

•Check engine light illuminated
•Rough idle
•Loss of power during acceleration
•Increased fuel consumption
•Engine stalling at low speeds

Diagnostic Steps

1
Scan for error codes using an OBD-II scanner to identify specific trouble codes.
2
Inspect the engine air filter for clogs or restrictions that may affect air intake.
3
Check the spark plugs and ignition coils for wear or failure.
4
Test fuel pressure to ensure the fuel pump is functioning correctly.
5
Inspect for vacuum leaks in hoses and intake manifold.
6
Examine the exhaust system for any blockages or leaks.

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
•Smoke machine or carburetor cleaner
•Fuel pressure gauge

Parts Required

•Spark plugs
•Ignition coils
•Air filter
•Fuel pump (if diagnosed as faulty)
•Vacuum hoses (as necessary)

Related Faults

Share this solution

Comments

No comments yet

Be the first to share your thoughts

Back to Generation

Diagnostic Steps

1
Scan for error codes using an OBD-II scanner to identify specific trouble codes.
2
Inspect the engine air filter for clogs or restrictions that may affect air intake.
3
Check the spark plugs and ignition coils for wear or failure.
4
Test fuel pressure to ensure the fuel pump is functioning correctly.
5
Inspect for vacuum leaks in hoses and intake manifold.
6
Examine the exhaust system for any blockages or leaks.

Solution

1. Preparation

Gather necessary tools and parts.
Disconnect the negative battery terminal to ensure safety.
Allow the engine to cool down before beginning work.

2. Replace Spark Plugs and Ignition Coils

Tools Required: Socket set, ratchet, torque wrench, dielectric grease.
Remove the engine cover (if applicable) by unscrewing the retaining bolts.
Disconnect the ignition coil connectors and remove the ignition coils using a socket.
Remove the old spark plugs using a spark plug socket. Inspect for wear or damage.
Insert new spark plugs and torque to manufacturer specifications (typically 13-16 lb-ft).
Apply dielectric grease to the inside of the ignition coil boots and reinstall the ignition coils.
Reconnect the ignition coil connectors and replace the engine cover.

3. Inspect and Replace Air Filter

Tools Required: None, or a screwdriver if clips are present.
Remove the air filter housing cover by loosening clips or screws.
Take out the old air filter and inspect for dirt and debris.
Install a new air filter and secure the housing cover.

4. Check for Vacuum Leaks

Tools Required: Smoke machine or carburetor cleaner.
Visually inspect vacuum hoses for cracks or loose connections.
Use a smoke machine to detect leaks or spray carburetor cleaner around suspected areas while the engine is idling. If RPMs change, a leak is present.
Replace any damaged hoses or gaskets.

5. Test and Replace Fuel Pump (if necessary)

Tools Required: Fuel pressure gauge, socket set.
Connect the fuel pressure gauge to the fuel rail test port.
Turn the ignition on (do not start) and check the pressure reading against manufacturer specifications (typically between 30-50 psi).
If pressure is low, replace the fuel pump as per manufacturer instructions.