why does my Ford F-150 13th Generation (2015-2020) check engine light turn on and off

Ford F-150 13th Generation (2015-2020)

Error Codes

2-4 hours

Time

medium

Difficulty

medium

Severity

3 min read

551 words

Problem Statement

Learn how to diagnose and fix the intermittent check engine light issue in Ford F-150 (2015-2020). Step-by-step guide with symptoms and solutions.

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 working to avoid burns.

Symptoms

•Check engine light illuminated intermittently
•Engine running rough or misfiring at times
•Decreased fuel efficiency
•Unusual engine noises (knocking or pinging)
•Difficulty starting the engine on occasion
•Smell of fuel or exhaust odors inside the cabin

Diagnostic Steps

1
Scan for error codes using an OBD-II scanner to identify specific trouble codes.
2
Inspect the gas cap for proper sealing and condition; a loose or damaged cap can trigger the light.
3
Check for any visible vacuum leaks in the intake system or hoses.
4
Perform a visual inspection of the ignition system components (spark plugs, wires, coils).
5
Examine fuel trim data using the scanner to assess for lean or rich conditions.
6
Verify sensor functionality, including Mass Air Flow (MAF) and Oxygen sensors.

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
•MAF cleaner
•Vacuum gauge (optional)

Parts Required

•New gas cap
•Spark plugs
•Ignition coils (if faulty)
•MAF sensor (if needed)
•Oxygen sensors (if indicated)

Related Faults

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Diagnostic Steps

1
Scan for error codes using an OBD-II scanner to identify specific trouble codes.
2
Inspect the gas cap for proper sealing and condition; a loose or damaged cap can trigger the light.
3
Check for any visible vacuum leaks in the intake system or hoses.
4
Perform a visual inspection of the ignition system components (spark plugs, wires, coils).
5
Examine fuel trim data using the scanner to assess for lean or rich conditions.
6
Verify sensor functionality, including Mass Air Flow (MAF) and Oxygen sensors.

Solution

1. Preparation

Gather all necessary tools and parts.
Ensure the vehicle is parked on a flat surface and the engine is cool.
Disconnect the battery to prevent electrical shorts while working.

2. Addressing Faulty Components

A. Gas Cap Replacement

Remove the existing gas cap.
Inspect the sealing surface for damage; replace if necessary.
Install a new gas cap, tightening it until you hear a click.

B. Spark Plug and Ignition Coil Replacement

Remove the engine cover if applicable.
Disconnect the electrical connectors from the ignition coils.
Use a socket set to remove the ignition coils.
Replace the spark plugs with new ones, ensuring the gap is correct (typically 0.054 inches for F-150).
Reinstall the ignition coils and reconnect electrical connectors.

3. Inspecting and Replacing Sensors

Locate the MAF sensor and disconnect the electrical connector.
Remove the MAF sensor using a Torx screwdriver.
Clean the MAF sensor with MAF cleaner or replace if defective.
Check and replace any malfunctioning O2 sensors as indicated by error codes.

4. Check for Vacuum Leaks

Inspect all vacuum hoses for cracks or disconnections.
Use a smoke machine or carb cleaner to locate leaks.
Replace any damaged hoses or repair leaks as needed.