What can I check when the check engine light comes on?

What do I check when the check engine light comes on? 

Check engine light on the dash

If the check engine light comes on, start by checking the tightness of your gas cap. We have seen several times that the check engine light is illuminated by either a loose gas cap or a gas cap that wasn't fully seated after a fill up.

A few other things that you can inspect yourself when the check engine light comes on:

1. Open the hood and look for any loose electrical connectors.

2. Under the hood, check for the main air intake hose (from the air filter box to the engine) for proper connections, any cracking on the hose, and any loose or disconnected vacuum lines.

3. Look under the vehicle and check for any leaking fluids or hanging components. We have seen where road debris can cause damage, which in turn will illuminate the check engine light.

4. Check your vehicle gauges to make sure the temperature gauge isn't too hot - ("too hot" is any time the needle goes past the middle point between cold and hot.)

5. Check the engine oil level and condition to make sure it's clean and not too low.

6. Check the battery connections and wires for loose components. 

Why does the check engine light come on?

When the check engine light comes on, the vehicle's computer is telling you that one or more of it's components noticed something in the vehicle's system is not operating correctly.

If your check engine light fault is not severe, you car is smart enough to use assumed values which will allow you to continue to drive. There are other times, like when your check engine light starts flashing, when your check engine is telling you that you should not drive your car and if you do, you could cause damage to your car.

The last thing that could happen when your check engine light comes on... your car might not start or the car may cut out on you.

Will the check engine light turn itself off? 

Check engine light and other warning lights on the dash.

If you were able to fix the issue with the check engine light, your light will actually turn itself off.

Most vehicles that are 1996 and newer have a process where the vehicle computer runs tests every time you run your vehicle. After each test, the computer reports and gives a pass or a fail to the car's components. If the vehicle sees a pass on all of the vehicle components, on the third drive cycle, the check engine light will no longer be on the dash. 

We hope this article was helpful to understand what to do when the engine light or service engine soon light comes on your dash!

You can check out our other article to learn more about what happens if you can drive with the check engine light on. If you need any other help, please feel free to give is a call 650-946-1856 Justin, Jason, & Naeem or book an appointment. 

Categories: Car Maintenance
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