why does my Toyota Highlander Third Generation (2014-2019) check engine light keep coming on

Toyota Highlander Third Generation (2014-2019)

Error Codes

2-4 hours

Time

medium

Difficulty

medium

Severity

3 min read

538 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

2-4 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

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

Symptoms

•Check engine light illuminated
•Rough idle or engine hesitation
•Decreased fuel efficiency
•Increased exhaust emissions
•Unusual noises from the engine compartment

Diagnostic Steps

1
Scan for error codes using an OBD-II scanner to identify specific trouble codes.
2
Inspect the gas cap for damage or improper sealing.
3
Check engine oil level and condition to rule out lubrication issues.
4
Examine the air filter for blockage or dirt buildup.
5
Inspect the exhaust system for leaks or damage.
6
Test the ignition system components (spark plugs, coils) for faults.

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
•Safety goggles
•Gloves

Parts Required

•Replacement gas cap (if needed)
•Engine oil and filter (if oil change is necessary)
•Replacement air filter (if needed)
•Ignition coils or spark plugs (if faulty)

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 gas cap for damage or improper sealing.
3
Check engine oil level and condition to rule out lubrication issues.
4
Examine the air filter for blockage or dirt buildup.
5
Inspect the exhaust system for leaks or damage.
6
Test the ignition system components (spark plugs, coils) for faults.

Solution

1. Preparation

Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, safety goggles, gloves.
Allow the engine to cool before starting any work.
Disconnect the battery negative terminal to ensure safety.

2. Addressing Error Codes

Connect the OBD-II scanner to the vehicle's diagnostic port.
Retrieve and note any error codes present.
Refer to a repair manual to interpret the codes and identify the affected components.

3. Gas Cap Inspection and Replacement

Remove the gas cap and inspect for cracks or damage.
Clean the filler neck to ensure a proper seal.
If damaged, replace the gas cap with a new one (OEM recommended).

4. Engine Oil Check

Remove the dipstick and wipe it clean.
Reinsert the dipstick and pull it out again to check the oil level.
If oil is low or very dirty, change the engine oil and filter as necessary.

5. Air Filter Replacement

Locate the air filter housing and open it using a socket set.
Remove the old air filter and inspect for dirt or blockages.
Install a new air filter, ensuring it fits snugly in the housing.

6. Ignition System Inspection

Remove the engine cover if applicable.
Disconnect ignition coils and inspect for cracks or corrosion.
Use a multimeter to test the resistance of the ignition coils.
Replace any faulty ignition components as needed.