FAULTBASE
Error CodesASKCars
© 2025 FAULTBASE
All rights reserved.
v2.0.0 • Production
ContactPrivacyImpressum
Home/Cars/Ford/F-150/13th Generation (2015-2020)/how to diagnose P0303 misfire code on Ford F-150 13th Generation (2015-2020)

how to diagnose P0303 misfire code on Ford F-150 13th Generation (2015-2020)

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

Error Codes
Severity: highDifficulty: mediumError Code: P03032-4 hours
4 min read
673 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 P0303 cylinder 3 misfire in Ford F-150 (2015-2020). Step-by-step guide with diagnostic procedures and repair instructions.

Error Code
P0303
Affected Component
Engine
Estimated Time
2-4 hours

Safety Warnings

  • ⚠Disconnect the battery before working on electrical systems

Symptoms

  • •Check engine light illuminated
  • •Rough idle or engine shaking
  • •Decreased fuel efficiency
  • •Engine stalling or hesitation during acceleration
  • •Increased exhaust emissions
  • •Unusual engine noises, such as backfiring

Diagnostic Steps

  1. 1Scan for error codes using an OBD-II scanner to confirm the presence of the P0303 code and any other related codes.
  2. 2Inspect the spark plug in cylinder 3 for wear or damage; replace if necessary.
  3. 3Check the ignition coil for cylinder 3 by swapping it with another cylinder and monitoring for changes in misfire codes.
  4. 4Examine the fuel injector functionality in cylinder 3 using a noid light or a multimeter to ensure it is receiving power and functioning correctly.
  5. 5Perform a compression test on cylinder 3 to check for mechanical issues such as low compression due to worn rings or a blown head gasket.
  6. 6Inspect the wiring and connectors related to the ignition system and fuel injector for any signs of wear, corrosion, or disconnection.

Solution

Solution

1. Preparation

  • Gather tools and materials.
  • Disconnect the negative battery terminal to ensure safety.
  • Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, compression tester.

2. Replace Spark Plug

  1. Remove the engine cover if applicable.
  2. Disconnect the spark plug wire or ignition coil connector from cylinder 3.
  3. Use a socket wrench to remove the spark plug from cylinder 3.
  4. Inspect the spark plug for signs of excessive wear or deposits; replace if necessary.
  5. Install a new spark plug, tightening it to the manufacturer's specified torque (typically around 13-15 lb-ft).
  6. Reconnect the spark plug wire or ignition coil connector.

3. Test and Replace Ignition Coil (if necessary)

  1. Swap the ignition coil from cylinder 3 with another cylinder.
  2. Clear the P0303 code using the OBD-II scanner and start the engine.
  3. Monitor for any new misfire codes; if the code moves to the cylinder where the coil was swapped, replace the ignition coil at cylinder 3.
  4. Install the new ignition coil and reconnect the electrical connector.

4. Inspect and Replace Fuel Injector (if necessary)

  1. Disconnect the fuel injector connector from cylinder 3.
  2. Use a noid light or multimeter to check for power to the fuel injector.
  3. If no power is detected, trace wiring back to the ECM and repair as necessary.
  4. If power is present and the injector is faulty, remove the fuel rail to access the injector.
  5. Replace the fuel injector with a new one and reassemble the fuel rail.

5. Perform Compression Test

  1. Remove the spark plug from cylinder 3.
  2. Insert a compression tester into the spark plug hole and crank the engine.
  3. Record the compression reading; it should be within manufacturer specifications (usually between 120-150 psi).
  4. If compression is low, investigate further for potential internal engine issues.

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
  • •Compression tester
  • •Noid light

Parts Required

  • •Spark plug (if worn or damaged)
  • •Ignition coil (if faulty)
  • •Fuel injector (if malfunctioning)

Additional Information

Error Code
P0303
Affected Component
Engine
Estimated Time
2-4 hours
Difficulty
medium
Severity
high
Tools Required
6 items
Parts Required
3 items

Related Faults

  1. how to diagnose Ford F-150 13th Generation (2015-2020) air intake issues

    Learn how to diagnose and fix air intake issues in Ford F-150 13th Generation (2015-2020). Step-by-step guide with symptoms, diagnostic steps, and repair instructions.

    Engine6 symptoms

  2. how often should I replace the air filter in my Ford F-150 13th Generation (2015-2020)

    Learn how often to replace the air filter in your Ford F-150 13th Generation (2015-2020). Step-by-step guide with symptoms, diagnostic steps, and tools required.

    Engine5 symptoms

  3. how to fix the fuel gauge not working on my Ford F-150 13th Generation (2015-2020)

    Learn how to diagnose and fix the fuel gauge issue on your Ford F-150 (2015-2020). Step-by-step guide with symptoms, diagnostic steps, and repair instructions.

    Fuel System5 symptoms

  4. how to troubleshoot Ford F-150 electrical problems with no power

    Learn how to troubleshoot and fix electrical problems in Ford F-150 with no power. Step-by-step guide with diagnostic steps and repair instructions.

    Electrical5 symptoms

  5. how to fix transmission jerking on Ford F-150 13th Generation (2015-2020)

    Learn how to diagnose and fix transmission jerking in Ford F-150 13th Generation (2015-2020). Step-by-step guide with symptoms, diagnostics, and repair instructions.

    Transmission5 symptoms

  6. why is my Ford F-150 13th Generation (2015-2020) not shifting smoothly

    Learn how to diagnose and fix transmission shifting issues in Ford F-150 13th Generation (2015-2020). Step-by-step guide with diagnostic procedures and repair instructions.

    Transmission6 symptoms

Share this solution

Comments

Sign in to share your thoughts

Sign In

No comments yet

Be the first to share your thoughts

Back to Generation