What Does My Check Engine Light Mean?


It can be troubling to understand what the little yellow light is trying to tell you the moment it
pops up on your dash. You no longer trust your car and wonder if you will get to where
you’re headed? Is it safe to drive, or will you cause additional damage to your car by continuing
to drive it?

It could be a simple harmless problem. Something as simple as a loose gas cap that
could be the culprit, or it could be the precursor to a major meltdown such as catalytic converter,
misfiring engine, malfunctioning sensors, but one thing is for certain, your car is telling you that
something is wrong.

Here Are 8 Typical Warning Light Causes:

1. Loose Gas Cap

The fuel cap does more than just prevent fuel from leaking out, it
provides a seal allowing the fuel system to become pressurized. If your fuel cap is loose
or doesn’t seal well, the check engine light will come on. Often, tightening the cap is
enough, but the fuel cap might need to be replaced if the seal is broken.

2. Thermostat

In the cooling system, the most common failure is the thermostat that
regulates your engine temperature through coolant flow. If the thermostat gets stuck
open, the engine may never reach its ideal temperature or if the thermostat is stuck
closed, your engine can easily overheat. If the engine has overheated, the head gasket,
and more, might need to be replaced.

3. Ignition System

If the check engine light is flashing, it’s likely due to an ignition system problem, which includes spark plugs, ignition cables, or an ignition coil. These
parts are responsible for igniting the fuel in each engine cylinder and when the fuel does
not ignite properly, or there is no spark at all, it’s known as a misfire. A misfire will turn
on your check engine light and severe misfires will set your check engine light blinking.
If you delay misfire repairs, you can cause additional problems like a flooded engine or
catalytic converter failure.

4. Mass Air Flow Sensor

The mass air flow sensor meters the air that is drawn into your
engine, either through the airbox or in the ductwork from the air filter to the intake.
Inaccurate air metering can cause stalling, excessive fuel consumption and run rough.

5. Faulty Oxygen Sensors

The purpose of the oxygen sensor is to measure the emissions
in the exhaust, and the readings are used to adjust your engine’s performance in real-time.
Most vehicles have two oxygen sensors. If an oxygen sensor is faulty, you could see a
drop in fuel efficiency or poor engine performance. It can cause your engine to run lean,
which could result in permanent, debilitating engine damage over the long haul.

6. Catalytic Converter

If the catalytic converter is on its way out then the check engine
light will be on and you may notice a very unpleasant rotten egg odor or a rattling noise
underneath your vehicle. Unfortunately, the catalytic converter is one of the more
expensive repairs you may need to tackle on your vehicle.

7. Emissions Sensors

A whole slew of emissions sensors can cause your car warning lights
to come on. The emissions system is responsible for ensuring the cleanest engine
operation possible and has several aspects. There is an exhaust gas recirculation (EGR)
system, a purge control system, evaporative emissions, and others. If a purge control
valve or solenoid is stuck, the check engine light will likely be on constantly.

8. ABS Brakes

You may also notice other warning lights such as the ABS light. It can be
an issue with a wheel speed sensor, which can affect your ABS brakes and traction
control. It can also affect your stability control system or it could be a leak in the ABS
hydraulic control unit which can affect your power brakes. Possibly it could be the ABS
control module at fault, which influences your braking system. The proper repair can be
as simple as a wiring repair. It may require a replacement wheel hub that houses the ABS
wheel sensor, or it may be the module or control unit that needs to be changed. This
innocuous light can be quite expensive to fix.

If your check engine light has come on, it does not necessarily mean you need to call a
tow truck, but you will need to get your vehicle checked out. Although it is tempting to ignore
having your car checked, ignoring the check engine light can result in a greater risk of
mechanical expenses.

Schedule your vehicle with Power Automotive today and our experts will conduct a complimentary full
diagnostic scan on your vehicle and reveal why the check engine light has come on, from there
we will advise what is the recommended course of action to properly repair your vehicle.

Schedule an Appointment

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