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5 Of The Most Common Reasons For A Lit Check Engine Light

5 Of The Most Common Reasons For A Lit Check Engine Light | H B Auto & AC

Your vehicle's dashboard is a complex combination of all kinds of information, but among all, the check engine light can be a cause for concern. Don't be intimidated! We'll unravel the five most common reasons why the check engine light comes on and show you how to take proactive steps to avoid these issues. 

The Unassuming Fuel Cap 

It is a seemingly trivial oversight, yet one that holds surprising sway over the check engine light – the fuel cap. A loose or damaged fuel cap can trigger the light to illuminate, signaling potential issues with the evaporative emissions system.

The remedy? Ensure your fuel cap is securely tightened after each refueling. This simple act can circumvent unnecessary visits to the mechanic and keep the check engine light at bay.

Sensor Signals

In modern vehicles, a network of sensors controls basically everything. Any hiccup can result in the check engine light taking center stage. From oxygen sensors to mass airflow sensors, a malfunction in these vital components can disrupt the engine's equilibrium. Sometimes, it might even result in the vehicle entering safe mode or refusing to start up.

Make sure to adopt frequent maintenance checks, including sensor diagnostics, which can preemptively identify issues and maintain a delicate balance.

Ignition Problems

The ignition system, responsible for igniting the air-fuel mixture in the engine, is another arena where check engine light battles unfold. Faulty spark plugs or ignition coils can lead to misfires, causing the ECU to signal potential problems. And when they become imminent, it might start flashing in an effort to grab the driver's attention.

A flashing check engine light should be checked by a professional ASAP!

Emission System Malfunctions 

Issues within the exhaust system, such as a malfunctioning catalytic converter or oxygen sensor, can prompt the check engine light to signal a disturbance. Emission system checks, coupled with prompt replacements when needed, not only preserve air quality but also keep the check engine light from casting its glow on your dashboard.

Old or Problematic Battery 

The humble yet indispensable battery can also play a role in the check engine light saga. A weak or failing battery can cause voltage fluctuations, triggering the light to shine. Inspections, especially before the colder months, help preemptively identify battery issues and ensure a robust electrical system that keeps the check engine light from becoming an unwelcome companion.


Come by H B Auto & AC, and we will get rid of that annoying check engine light! While we are at it, we can also check all other systems, so why not book an appointment?

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