2021 Ford Mustang Mach-E Has A Check Engine Light

Troubleshooting the Check Engine Light in Your 2021 Ford Mustang Mach-E: Common Causes and Solutions

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Reviewed by
Aisha
Written by RepairPal Car Genius
Updated January 14, 2025
0%
40% chance it's the
Emissions System
0%
60% chance it's
Something else
The most common reasons a 2021 Ford Mustang Mach-E has a check engine light are an emissions system component, a sensor, or a catalytic converter.
  • Emissions System: A faulty emissions system component, such as an oxygen sensor or EGR valve, can lead to increased emissions and trigger the check engine light.
Proper diagnosis will determine the exact cause of your symptom, saving you money on unnecessary repairs. The diagnostic experts at RepairPal Certified shops have the right tools and experience to solve any symptom.

How much does it cost to fix a 2021 Ford Mustang Mach-E has a check engine light?

Common Repairs

The total repair cost will vary based on the condition of your vehicle and the number of repairs needed to fix your symptom. Proper diagnosis will save you money by finding the exact repairs needed to fix your car right the first time.

Due to the nature of electrical systems on modern vehicles, the range of problems these can cause are nearly limitless. However, there is a way to categorize them in two ways. Permanent and intermittent problems. Permanent problems appear and remain. This may be the vehicle will not start, the radio does not work, or the door chime will not turn off among many, many others. These problems are more straight-forward to diagnose since they present themselves at all time. This means there will always be a fault to find. Intermittent electrical problems, however, can be difficult or impossible to locate, since they appear then disappear without warning. The best case scenario for an intermittent issue is when replicating the problem is easily accomplished and understood. This allows a technician to make an issue semi-permanent, allowing them to find the fault. Other issues that come and go without warning and cannot be replicated on demand must occur when the technician is servicing the vehicle, otherwise there is no problem to correct. It is most important to understand that electrical system faults always require inspection, and can include the vehicle working in any manner, or not working at all.

Like we noted in the last section, general diagnosis symptoms are the most vague of the bunch. There are several diagnostic spectrums, electrical diagnosis, drivability diagnostics, engine diagnostics, transmission diagnostics, and the list could continue for about 5 or 10 more spectrums of diagnostics. The most important take-away here, is that general diagnostics are diagnostics that have no other spectrum in which they fit, or the problem is unknown. This means that any vehicle left outside of a repair facility with the keys and an authorization to perform diagnosis will be diagnosed under the general diagnosis spectrum.

When the Check Engine Light comes on, you may experience engine performance issues such as poor acceleration, rough idling, or an engine that won't start. In some cases, no abnormal symptoms will be experienced. Other systems like the transmission or ABS can cause the Check Engine Light to illuminate and lights for those systems can come on at the same time. Similar lights may say "Check Engine Soon", "Malfunction Indicator Light" or just "Check". In rare case the engine can overheat.

What are the initial diagnostic steps to take for a check engine light on a 2021 Ford Mustang Mach-E?

When faced with a check engine light on your 2021 Ford Mustang Mach-E, it's essential to approach the situation methodically to identify the underlying issue. Start by checking for any additional warning lights on the dashboard, as these can offer crucial insights into the problem. Next, inspect the gas cap; a loose or damaged cap is a common culprit that can easily trigger the check engine light. Following this, conduct a visual inspection of the vehicle for any signs of damage, such as leaks or loose wiring, which could indicate a more significant issue. If these initial checks do not resolve the light, using an OBD-II scanner to retrieve error codes from the vehicle's computer system can provide specific information about the malfunction. Finally, consulting the owner's manual can offer tailored guidance on what the check engine light may signify and the recommended next steps. By following this structured diagnostic approach, you can effectively narrow down the cause of the check engine light and take appropriate action.

What are the common problems that could cause the check engine light to illuminate in a 2021 Ford Mustang Mach-E?

When the check engine light comes on in a 2021 Ford Mustang Mach-E, it can be a source of concern for any DIY car owner. One of the most straightforward issues to check is the gas cap; a loose or damaged cap can easily trigger the light, so ensuring it is secure is a good first step. If the gas cap is fine, consider inspecting the oxygen sensor, as a faulty sensor can lead to reduced fuel efficiency and may require replacement. Additionally, problems with the catalytic converter can also illuminate the check engine light, often indicating a failure or inefficiency that needs attention. Spark plugs are another common culprit; worn or faulty plugs can affect engine performance and should be checked regularly. The mass airflow sensor is crucial for maintaining the correct air-fuel mixture, and if it malfunctions, it can cause the light to activate. Ignition coil issues can lead to engine misfires, which are also a common reason for the check engine light to illuminate. Lastly, don’t overlook the exhaust gas recirculation (EGR) system, as a clogged valve can trigger the warning light as well. Addressing these issues promptly not only helps in maintaining optimal vehicle performance but also prevents potential damage, making it essential for DIY enthusiasts to stay vigilant.

What are the potential risks of ignoring the check engine light on a 2021 Ford Mustang Mach-E?

Ignoring the check engine light on your 2021 Ford Mustang Mach-E can lead to serious repercussions that extend beyond mere inconvenience. The initial warning may indicate minor issues, but neglecting it can escalate into significant engine damage, resulting in costly repairs that could have been avoided with timely attention. Additionally, unresolved problems can adversely affect your vehicle's fuel efficiency, leading to higher fuel costs and increased environmental impact due to elevated emissions. Safety should also be a primary concern; overlooking the check engine light may mean ignoring critical issues that could compromise your vehicle's performance on the road. Furthermore, what starts as a small problem can snowball into a larger, more complex issue, necessitating extensive repairs and downtime. Therefore, addressing the check engine light promptly is crucial not only for the longevity of your Mustang Mach-E but also for your safety and financial well-being.

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