2012 Mazda 5 Has A Check Engine Light

Common Causes of the Check Engine Light in Your 2012 Mazda 5 and How to Resolve Them

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Reviewed by
Andrew Hajjar
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 2012 Mazda 5 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 2012 Mazda 5 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.

A faulty oxygen sensor is one of the most common causes of a check engine light. Symptoms may include a decrease in fuel mileage, hesitation or misfiring from the engine, rough idling or even stalling. A faulty sensor may cause the vehicle to fail an emissions test.

Any time there is an emissions fault the check engine light will be displayed. The purpose of the check engine light is to inform the driver that an emission related fault has been found, and that there are on-board diagnostic (OBD) trouble codes stored in the powertrain or engine control module. Additionally, since the emissions systems are so intertwined into engine control and transmission control systems, symptoms may include nearly any sort of drivability concerns. This may include harsh shifting, failure to shift, hesitation on acceleration, jerking, engine failure to start or run, loss of power, or any number of other drivability issues.

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 steps to diagnose the check engine light on a 2012 Mazda 5?

To effectively diagnose the check engine light on your 2012 Mazda 5, start with a thorough visual inspection of the vehicle. Begin by checking the gas cap; ensure it is securely tightened and free from damage, as a faulty gas cap is a common trigger for the check engine light. Next, utilize an OBD-II diagnostic scanner, which can be connected to the vehicle's OBD port. This tool will help you retrieve specific error codes that indicate the nature of the problem. Once you have the error code, refer to your vehicle's manual or reliable online resources to interpret its meaning, which will guide you in identifying the affected system. Additionally, inspect essential components under the hood, such as engine oil and coolant levels, as low fluids can also activate the check engine light. If these initial steps do not reveal the issue, consider seeking professional assistance for a more in-depth diagnosis. By following this structured approach, you can efficiently narrow down the potential causes of the check engine light and take the necessary steps toward resolution.

What are the common problems that could cause the check engine light to illuminate in a 2012 Mazda 5?

When the check engine light comes on in a 2012 Mazda 5, it can be a source of concern for any driver. Understanding the common problems that may trigger this warning can empower you to take action. One frequent culprit is a loose gas cap, which can allow fuel vapors to escape, leading to the light's illumination. Another common issue is a faulty oxygen sensor, which not only affects fuel efficiency but also impacts emissions, prompting the check engine light to activate. Additionally, problems with the catalytic converter, such as inefficiency or failure, can also be a reason for concern. Ignition issues, including malfunctioning spark plugs or ignition coils, can disrupt engine performance and trigger the light as well. Furthermore, a malfunctioning mass airflow sensor can lead to an improper air-fuel mixture, causing the check engine light to illuminate. Engine misfires, often due to bad spark plugs or fuel injectors, are another potential cause. Lastly, issues with the Exhaust Gas Recirculation (EGR) valve can lead to emissions problems, resulting in the check engine light turning on. By being aware of these common issues, you can better diagnose the problem and take the necessary steps to address it.

How urgent is it to address the check engine light in a 2012 Mazda 5?

When the check engine light illuminates in your 2012 Mazda 5, it is essential to recognize the urgency of the situation. This warning indicator is not merely a nuisance; it signifies potential issues within the engine or emissions system that could escalate if left unaddressed. Ignoring this light can lead to more severe complications, including costly repairs or even a complete breakdown, which can compromise your safety on the road. For DIY enthusiasts, the first step is to use an OBD-II scanner to retrieve diagnostic trouble codes, which can provide insight into the specific problem. However, while some issues may be minor, others could indicate significant engine damage or safety risks, making it crucial to assess the situation promptly. By addressing the check engine light quickly, you not only safeguard your vehicle's performance and fuel efficiency but also prevent further damage that could lead to more extensive repairs down the line. Therefore, taking immediate action is vital for maintaining the health of your Mazda 5 and ensuring a safe driving experience.

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