Noticing that dreaded check-engine icon appear on your dashboard can be worrying, as you know there’s likely an issue preventing your Subaru from running at its best. There are countless reasons that this light could be active, however, there are some causes that are more frequently seen.
In this article, we’ll go over what the check engine light means, the common causes of it illuminating on your dashboard, and what these issues could mean for the health of your vehicle.
What Is a Check Engine Light?
The check engine light (CEL) is one of your Subaru’s most important ways of relaying important information about the state of critical systems in your vehicle. While modern vehicles use an array of different warning lights to let the driver know of particular issues, the check engine light covers many of the systems relating to your powertrain.
If you notice a check engine light appearing on your own vehicle, it’s vital to ensure you have it inspected by a trusted professional right away, as the meaning of check engine lights can range anywhere between slight efficiency issues to major malfunctions that could cause irreparable damage to your engine if not addressed.
Frequent Causes of a Check Engine Light on Subarus
Loose Gas Cap
While a slightly loose or damaged gas cap may seem like a pretty minor issue, the lack of an air-tight seal can trick the sensors into believing the EVAP system is experiencing issues, triggering a check engine light on your dashboard.
Fortunately, this is also the easiest of these issues to remedy, as all you need to do is retighten your gas cap, or swap it out with an inexpensive replacement if the rubber seal has become damaged.
Malfunctioning Mass Airflow (MAF) Sensor
The mass airflow sensor is responsible for monitoring the volume of air being introduced into the combustion chamber. It sits just past the intake’s airbox, and relays information on the amount of air entering to the vehicles computer, which is used to alter the air-fuel ratio and keep the engine running optimally.
When this sensor experiences issues, whether that be due to damage, contamination and dirt, or simply old age, it can prevent the vehicle’s computer from receiving a proper reading on airflow, which can lead to an incorrect air-fuel ratio. Not only will this lead to a check engine light, it may also cause your engine to run inefficiently, losing performance and fuel economy. If left to linger, incorrect air-fuel mixtures can also lead to damage within the engine or to surrounding components such as the catalytic converters.
Bad Oxygen Sensor
Similar to how the MAF reads the air entering the engine, the oxygen sensors (O2 sensors) are responsible for monitoring the volume of oxygen remaining in exhaust fumes as the exit your vehicle. The vehicle’s computer uses these readings to alter the air-fuel ratio, and a dirty or damaged sensor may cause similar problems to a faulty mass airflow sensor.
If you notice an O2 sensor warning when reading your fault codes, it’s important to have your vehicle inspected by a trusted professional as soon as possible to prevent further damage or issues as a result of the incorrect sensor information.
Ignition Issues
One of the more commonly seen issues on Subarus, specifically those with Boxer engines, is malfunctions in the ignition system. There are various reasons the spark plugs, ignition coils, and surrounding electrical components may fail, however there’s a good chance you’ll notice a check engine light appear along with issues starting the vehicle or keeping it running.
The check engine light will often light up red for ignition system issues, as these malfunctions can be fairly major and put your engine at risk of damage.
Subaru Maintenance, Diagnostics, & Repair in Boulder, CO
If you’re experiencing an active check engine light in your Subaru vehicle, don’t hesitate to reach out to the team at Super Rupair in Boulder. Our technicians have specialized training and equipment to take on any potential issues you’re facing. We only work on Subarus, so you can always have peace of mind that your vehicle in is the hands of technicians that understand your platform front to back. Give us a call today or schedule online to secure your appointment at the premier Subaru care and repair facility in the Boulder area!