How To Reset Check Engine Light On Ford F350?

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Key Takeaways:

  • The check engine light on a Ford F350 comes on when there is a problem detected with the vehicle’s emissions control system.
  • Resetting the check engine light does not fix the underlying problem that caused it to come on.
  • Common methods to reset the check engine light include disconnecting the battery and using an OBD2 scanner tool.
  • It’s recommended to have the vehicle properly diagnosed if the light comes back on after resetting.
  • Resetting the light erases any diagnostic trouble codes that were stored in the computer related to the issue.


The dreaded check engine light. As a Ford F350 owner, few things can be more annoying than seeing that bright amber engine warning light suddenly illuminate on your dashboard. Immediately your mind goes to the worse case scenarios — an expensive repair bill, a lengthy downtime for your truck, and a dent in your wallet.

While in some cases the underlying issue triggering the check engine light may be serious, the light itself is just an indicator from the truck’s on-board computer that something is amiss. The computer has detected a problem with the vehicle’s emissions control system and illuminated the check engine light as a result.

This comprehensive guide will walk through the ins and outs of the check engine light on the Ford F350 Super Duty truck. You’ll learn what causes the light to come on in the first place, the different methods available to reset it, and when it’s recommended to seek professional technician help instead of just resetting the light yourself. With a detailed understanding of how the check engine light functions on this iconic Ford truck, you’ll be well equipped to handle that dreaded amber illumination if it ever happens to your own F350.

Learning to properly diagnose issues triggering the check engine light and understanding when you can simply reset it versus when professional help is needed will save you time, money, and headaches. By adopting the recommendations in this guide, you’ll be able to confidently maintain the health of your truck and quickly address potential problems signaled by the check engine light. Let’s get started unraveling the mysteries of this important dashboard warning on your Super Duty.

What Causes the Check Engine Light to Come On?

Before learning how to reset the check engine light, it’s important to understand the reasons it illuminates in the first place.

The check engine light is triggered by the truck’s complex onboard diagnostic system, known as OBD-II (On-Board Diagnostics, 2nd Generation) [1]. This computerized system is constantly monitoring the vehicle’s emissions control components, engine management system, and a host of other sensors throughout the truck [2].

If any issues or abnormalities are detected that may impact emissions or drivability, the OBD-II system turns on the check engine light to alert the driver. Here are some of the most common culprits [3]:

  • Faulty oxygen sensor – This sensor analyzes oxygen levels in the exhaust stream. If operating incorrectly, it sends wrong data to the computer throwing off ignition timing and fuel mixture.
  • Defective catalytic converter – The catalytic converter reduces toxic emissions. A damaged one results in higher emissions triggering the light.
  • Loose or faulty gas cap – A loose gas cap allows fuel vapors to escape, which the OBD-II system detects.
  • Spark plug and ignition issues – Faulty spark plugs, wires, coils etc. disrupt optimal engine firing triggering the light.
  • EVAP emissions leaks – Small leaks in seals and hoses in the Evaporative Emission Control (EVAP) system are detected.
  • Faulty mass air flow sensor – This sensor reports intake air volume. Inaccurate readings affect combustion leading to activation of the light.

Essentially any sensor or component responsible for regulating emissions that is damaged or malfunctioning can trigger the OBD-II to illumination the check engine light. It’s the onboard computer’s way of saying – “Hey something is wrong under the hood that needs your attention!”.

How to Reset Check Engine Light on Ford F350

Okay, the dreaded check engine light is glaring from your dashboard. Before spending money on repairs, one tempting option is to simply reset the light to turn it off. Let’s look at two common methods for resetting the check engine light on the Ford F350.

Method 1 – Disconnect the Battery

One way to reset the check engine light is by disconnecting the truck’s battery [4]. This erases power to the OBD-II computer, which resets all diagnostic information as well as the check engine light when power is restored. Here is the step-by-step process:


  1. Turn the ignition to the “off” position and remove the ignition key.
  2. Locate the battery under the hood – it will have a red (+) and black (-) connector.
  3. Use a wrench to first loosen the nut holding the black negative (-) connector to the battery terminal.
  4. Disconnect the negative connector from the battery terminal.
  5. Leave the connector disconnected from the battery for at least 15 minutes. This gives time for the computer to fully reset.
  6. Reconnect the negative battery connector back onto the battery terminal and tighten the nut with the wrench.
  7. Turn the ignition on and start the vehicle. The check engine light should now remain off.

Tip: Many auto parts stores offer free battery reset service if you don’t want to tackle this yourself.

Disconnecting the battery is an easy process accessible to all DIYers without any fancy tools. It offers a cost-free way to reset the check engine light and turn off the warning lamp. However, this method alone does not actually fix the problem that caused the light to come on in the first place.

Method 2 – Using an OBD-II Scanner Tool

The second method relies on using an onboard diagnostic (OBD-II) scanner tool to reset the check engine light [5]. This specialized automotive tool plugs into the truck’s computer data port in order to communicate directly with the OBD-II system . Here are the steps to follow when using such a scanner tool:


  1. Locate the data link connector port, which is typically under the dash on the driver’s side.
  2. Connect the scan tool cable connector to the data port.
  3. Turn on the scan tool and follow menu prompts to access stored diagnostic trouble codes (DTCs). These help identify the fault triggering the check engine light.
  4. Once DTCs are displayed on the scan tool, select the option to clear or erase DTCs per the tool’s instructions.
  5. Reset or clear the trouble codes from the truck’s computer memory. The check engine light will turn off after codes are cleared.
  6. Disconnect the scanner tool and start the engine to verify the check engine light remains off.

Using an OBD-II scanner is fast and easy with the right tool and still a DIY-friendly option. Scanner tools ranging from simpler code readers to sophisticated diagnostic tools are readily available at auto parts stores or online retailers. This grants the added benefit of pulling the DTCs to help determine the cause of the check engine light.

When Should the Check Engine Light be Reset?

Now that you know how to reset that pesky check engine light on your Ford F350, let’s go over some guidelines on when resetting the light is appropriate versus when you should send the truck to a professional technician instead.

Resetting the light is likely ok if:

  • The check engine light just came on for the first time. Resetting and monitoring may resolve a temporary glitch versus a persistent issue.
  • You recently repaired the suspected issue triggering the light. Resetting after repairs may turn off the light once the underlying problem is fixed.
  • Needed repairs are not urgent based on the diagnostic trouble codes pulled. Non-critical faults may be reset while you save up funds for maintenance.
  • The truck is due for emissions testing and the light needs to be off to pass inspection. Resetting turns off the light temporarily to get through testing.

Seeking professional diagnosis is recommended if:

  • The check engine light has come on repeatedly despite previous resets. A chronic light indicates an unresolved problem requiring expert diagnosis.
  • You are not able to identify or troubleshoot the cause based on DTCs or symptoms. Complex faults require specialized tools and knowledge.
  • The truck is running very rough with obvious drivability issues. Severe engine problems are beyond simple resets and may worsen if ignored.
  • Critical emissions components like the catalytic converter seem to be damaged based on loud exhaust noises or failed tests. Extensive repairs will be needed.

Resetting the check engine light on your F350 can provide a simple fix in some cases, especially if you just need to turn the light off temporarily to pass an emissions test or sell the vehicle. However, ignoring serious mechanical faults indicated by the warning light can lead to further damage and expensive repairs down the road. Analyzing any diagnostic trouble codes pulled from the OBD-II system and assessing noticeable symptoms will help you make an informed decision if self-resetting the light is appropriate or if it’s time to take your truck to the pros.

Frequently Asked Questions

How long does the check engine light stay on?

Once illuminated, the check engine light will remain on continuously until reset, or until the OBD-II system no longer detects the malfunction. The light serves as an ongoing indicator of a problem.

Will the check engine light reset itself?

The check engine light cannot reset itself. It must be manually reset either by disconnecting battery power or using an OBD-II scanner tool to clear diagnostic codes triggering the light.

Can you pass emissions test with check engine light on?

Most jurisdictions prohibit vehicles from passing emissions testing if the check engine light is illuminated. The exceptions are if the light is on for a known minor issue like a loose gas cap. For a solid pass, the light needs to be reset prior to emissions testing.

What happens when you ignore the check engine light?

Ignoring the check engine light risks allowing minor problems to escalate into major mechanical issues. Prolonged driving with the light on can lead to damaged emissions controls, lowered fuel economy, failed safety inspections, and possibly complete engine failure in worst cases.

Does AutoZone reset check engine lights for free?

Many auto parts stores including AutoZone offer free check engine light diagnosis services. Store employees can connect a code scanner tool to pull any diagnostic trouble codes. They typically provide code print-outs detailing the detected errors. Many stores will also reset/clear the check engine light as part of their free services.


The check engine light on your Ford F350 is designed to alert you to problems with the emissions control system. But with the right knowledge, you can determine when the light can simply be reset versus when professional diagnosis is required. Resetting the light is handy for passing emissions tests or selling the vehicle. However, ignoring severe mechanical faults can lead to safety issues, poor performance, and costly repairs.

Follow the battery disconnect or OBD scanner reset procedures outlined to turn the light off yourself when appropriate. But also rely on warning light diagnostics and visible symptoms to judge if repairs may be urgently needed. With a balanced understanding of check engine light causes and reset options, Ford F350 owners can take control when that amber indicator lights up their dashboard.

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