Troubleshooting Kia Check Engine Light On

DIY Cost: 15-30
Est. Time: 10-30 min
Difficulty: Intermediate

This guide will discuss most common problems that cause the Kia check engine light to come on and how to use an OBD-II Scan Tool to read the codes yourself.

Kia Check Engine Light (CEL) (also known as Service Engine Soon SES or MIL) should not stay on when you are driving. 


kia check engine light on

The Check Engine Light should stay on when you turn the ignition to ON position, and until you start the engine, the light should turn off.

If the light continues to stay on, that means there is a problem, and you need to read the codes with an OBD-II Scanner.

What does it mean when Kia Check Engine Light comes on?

kia check engine light onWhen your check engine light illuminates your Kia vehicle, it means that the vehicle's Electronic Control Unit (ECU), or computer, which controls many aspects of your Kia's operation, has found a problem with the engine or emissions system.

The ECU stores a diagnostic trouble code (DTC) in its memory, triggering your check engine light to turn on the dashboard.

Any number of things can cause this problem - it may be as simple as a loose gas cap, a problem with an incorrect fuel/air mixture, or something much more severe as an engine problem.

You will need to read the fault codes using an OBD-II as outlined in the next section.

What causes the Kia check engine to come on? 

The most common problem that triggers the check engine light on a Kia is old spark plugs, bad oxygen sensor, dirty mass airflow sensor, or a loose gas cap. 

Common problems that often cause Kia check engine light to say on include: 

  • Loose gas cap
  • Bad spark plugs
  • Faulty ignition coil
  • Bad oxygen sensor
  • Mass Air Flow (MAF) sensor
  • Catalytic converter faulty
  • EVAP System Fuel Leak

To determine why your Kia to check engine light is on, you should start by reading the fault codes. 

How to Reset Kia Check Engine Fault Codes

You can read Kia check engine light codes yourself using an OBD-II scanner. This method applies only to Kia vehicles that are the model year 1996 and newer.

  1. Locate the OBD-II port under the dashboard.
    kia sorento check engine light problems
  2. Plugin your scanner into the OBD-II port.
    kia optima check engine light problems
  3. Turn on the ignition. Do not start the engine.
    kia optima rio sportage sedona check engine light problems
  4. Allow the scanner to power on. 
  5. Select Read Codes on your scanner. Write down all the codes that are Present or Current. Fix all problems that trigger these fault codes. 
  6. Go back to the menu and select Fault Fault Codes. This will reset the check engine light on you, Kia. 

Can't reset the check engine light? First, you need to fix all the underlying problems that triggered the fault codes. Once those issues are addressed, you will be able to clear the check engine light. 

Many auto repair shops and auto parts stores such as Advance Auto Parts, AutoZone, or PepBoys will read your engine trouble codes for free.

What does it mean when Kia Check Engine Light Is Flashing On and Off? 

If the check engine light is flashing, it means there is a critical problem that needs to be addressed right away.

If this ever happens when you are driving, pull over as soon as it is safe to do so. Allow the engine to cool down.

When the check engine light is blinking, it is not safe to operate the vehicle.

This problem can affect Kia models such as:

  • Rio,
  • Sorento,
  • Sportage,
  • Soul,
  • Optima,
  • Spectra
  • Forte,
  • Amanti,
  • Sedona and other models.

Can I Reset the Kia Check Engine light by Disconnecting the Battery?

Resetting the Kia check engine light by disconnecting the battery is not recommended for the following reasons:

  • By disconnecting the battery, you do not fix the underlying problem that triggered the CEL.
  • If the problem is fixed, there is no need to disconnect the battery. CEL should reset (turn off) on its own within a few days.
  • This method will not work on many newer Kia cars.

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Troubleshooting Kia Check Engine Light On