No Check Engine Light When Key Is In On Position? What You Need To Do!

Got an issue with a no check engine light when key is in on position?

This can be concerning since the check engine light lets you know if there is a problem with your vehicle. Among the issues that it alerts you include a misfiring engine, faulty gas cap, or some other concerns.

But what if there is no check engine light? How will you know if there’s a problem? Here are reasons why this situation occurs and what can be done.

no check engine light when key is in on position

No Check Engine Light when Key Is In On Position

The check engine light comes in different colors such as yellow, amber or orange. If you see the light start to flash, it means that a serious problem is happening including a misfire that causes the catalytic converter to overheat quickly.

In case you don’t see the check engine light turning on, then it is a good thing. But if your dashboard used to display the check engine light, yet fails to come on now, then it may be possible that the warning light has burned out.

You can remove the sensor harness and check if this helps the light to turn on. If this works, then the system is functioning well. However, if it still won’t turn on, inspect the computer for codes in case there are sensors you have unplugged.

When you see a code and the light indicator says it is on, then it may be possible that the light burned out. You will need to have a mechanic replace the light and have it fixed to address this issue correctly.

Understanding The Codes

Some drivers may find it confusing to read the codes they see when inspecting the problem with the check engine light. This is why there are those who head over to their local mechanic check and diagnose the issue. The rate varies and could be somewhere around $75.

But you can also buy an inexpensive code reader online or from your local auto parts store. Then, you can search for the meaning of the code on a website. Other more sophisticated systems display the code in an app on their smartphone.

Some code readers have the benefit of letting you turn off or reset the check engine light. However, this action does not completely solve the problem when there is an underlying issue behind it.

Here are some of the common codes, what they mean, and how much a typical repair cost is:

  • Replace catalytic converter – $1,383
  • Inspect for loose fuel cap (replace or tighten) – $25
  • Replace faulty oxygen sensor – $243
  • Replace fuel injector – $448
  • Replace mass airflow sensor – $336
  • Replace thermostat – $236
  • Replace EVAP – $142
  • Replace ignition coil and spark plug – $389

It is also worth knowing that the check engine light may come on even when there is no issue with your car. It may simply be a humidity issue or other concerns. This is why the light should eventually turn off on its own.

But one thing is for certain – you should never ignore a check engine light that is on. It is saying something about your engine and the rest of your vehicle’s components. It could also be a loose gas cap, which reports a leak in the emissions system. So, if you see the light turn on, check the gas cap and tighten it if it is loose.

Read More: How Long Can I Drive With Bad Piston Rings?

Final Thoughts

When the check engine light is on even when key is in on position, there may be issues that trigger this to happen. This is why it is best to know the root of the problem by inspecting the causes and checking for codes that indicate an error.

The sooner you get this problem addressed, the less trouble will occur in the affected components and the more you can prevent expensive repair costs.

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