Hyundai Check Engine Light Stays On

Hyundai Check Engine Light Stays On

In a Hyundai, the check engine light comes on as soon as the onboard diagnostic system (OBD) detects an issue with the engine, Evaporative Emission Control System (EVAP), or transmission.

What Does the Check Engine Light Mean on a Hyundai?

When your Hyundai check engine light comes on, it means the Onboard Diagnostic System has detected a problem with the engine, emission, or transmission. A fault code gets stored in the Engine Control Module (ECM) and retrieved with a diagnostic OBD-II scanner via the OBD-II port under the dashboard.

If the ECM, sometimes called ECU, has detected a fault code and triggered the Check Engine Light (CEL) / Service Engine Light, don’t necessarily assume an engine problem.

The problem could be emission-related, and the car may drive fine. The diagnostics process’s first step is to read the fault codes via the OBD-II port under the dashboard.

You can read the codes yourself or have an auto mechanic. An auto mechanic or dealer technician uses specialized equipment (OBD-II scanners) to read the code from the car’s computer (ECU) via the OBD port.

How to Reset Hyundai Check Engine Light

check engine light on hyundai santa fe

Diagnosing Hyundai engine fault codes is easy.

A Hyundai owner can read Hyundai engine fault codes using an OBD-II scanner connected to the OBD-II port under the dashboard (see instructions below).

  1. Locate the OBD-II port. This is a sixteen-pin port located under the dashboard on the driver’s side. hyundai sonata check engine light on
  2. Plug your OBD2 scanner into the OBD-II 16-pin port. hyundai codes for check engine light on
  3. Turn the key on. All the dash lights should turn on. Don’t start the engine.
  4. The scanner turns on. Hit the SCAN or READ button on your OBD-II scanner. You will see fault codes, such as P0300. Write down the code and do research online on what those codes mean for Hyundai cars.PXL 20220312 003004456

  5. Read fault codes.
  6. Fix the problems you found in step five, reconnect the scanner, and select Clear Fault codes.

Fix the problem that caused the check engine light. You can use the scanner to clear the code or drive the car for a couple of days, and the light will turn off after four or five driving cycles.

Common problems that trigger the check engine light on a Hyundai

EVAP System

Typically when the Hyundai check engine is on, but the car drives fine, you most likely have an Evaporative Emission Control System (EVAP) code.

EVAP prevents gasoline vapors from escaping into the fuel tank and fuel system atmosphere.

how to clear hyundai check engineIn many cases that the check engine light turns ON in a Hyundai (Elantra, Sonata, Santa Fe, Accent), the car may still drive perfectly fine. This happens when you have an emissions-related problem.

The problem here may be something as simple as a loose gas cap.

Retightening or replacing the gas cap often will fix the check engine light.

If the problem is a loose or defective gas cap and you address it, the check engine light will turn off on its own, usually in a couple of days.

Related fault codes:

  • P0440 Evaporative Emission Control System Malfunction.
  • P0444 Evaporative Emission Control System Purge Control Valve Circuit Open
  • P0422 Main Catalyst Efficiency Below Threshold (Bank 1)
  • P0420 Catalyst System Efficiency Below Threshold (Bank 1)

Hyundai check engine light flashing, blinking.

If your Hyundai check engine light is flashing and the car is shaking, you have a serious engine malfunction, and you should avoid driving your car.

Check engine light flashing and blinking is a result of an engine misfire. You need to replace the spark plugs to fix this problem.

In some cases, the check engine light may also flash due to a bad ignition coil. All these are easy and inexpensive repairs and can be performed by any DIYer.

Don’t continue to drive a Hyundai that has triggered the check engine light and is shaking; you may cause serious damage to the engine.

Not only that, but if you are driving in heavy traffic, your engine will overheat.

Related fault codes:

  • P0300 Random/Multiple Cylinder Misfire Detected
  • P0301 Cylinder 1 Misfire Detected
  • P0302 Cylinder 2 Misfire Detected
  • P0303 Cylinder 3 Misfire Detected
  • P0304 Cylinder 4 Misfire Detected

Check Engine Light on / No Acceleration

what does check engine light mean on hyundai sonataIf your Hyundai will not accelerate and the check engine light is on, it is very likely that a faulty throttle position sensor.

Under these conditions, the car will barely move or accelerate.

Replacing the throttle position sensor is easy and can be completed by any DIYer in less than one hour.

Fault codes related to Hyundai CEL on, the car won’t accelerate.

  • P2135 Throttle/pedal position sensor/switch A/B voltage correlation
  • P2135 OBD-II Trouble Code: Throttle/Pedal Position Sensor/Switch A/B
  • P2106 FORD Throttle Actuator Control System – Forced Limited Power
  • P2127 Throttle/Pedal Position Sensor/Switch ‘E’ Circuit Low
  • P2138 Throttle/Pedal Position Sensor/Switch ‘D’/’E’ Voltage
  • P2101 P0222 P0123

Hyundai Check engine light and ESC on

If the check engine and ESC light come on, the accelerator pedal position switch has failed.

In such cases, the car will lose all power. Pressing the gas pedal to the floor will not change engine RPMs. The car won’t accelerate, but you can get your car up to 20 MPH.

Try restarting the car, as this may fix this problem temporarily. Hyundai sells a redesigned accelerator pedal position switch that should fix this problem.

Replacing the sensor at the dealer or a repair shop costs between $200-$450. Installing a used Hyundai Accelerator Pedal is another possible solution.


Hundreds of possible problems can cause the check engine light on a Hyundai. The most common issues are spark plugs, oxygen sensors, and catalytic converter failure. Instead of guessing what is wrong, use an OBD-II scanner to read the fault codes.


The YOUCANIC Full System Scanner can read and clear fault codes through every control module of your Hyundai vehicle. This scanner can also be used on all make and models.

We hope you find the Hyundai Check Engine Light Stays On guide helpful. Check these troubleshooting and repair guides for more help on your Hyundai.


  • Rushit Hila • ASE Certified

    Rushit Hila, an ASE-certified engineer (G1 Automotive Maintenance and Repair), brings over two decades of hands-on experience in the automotive world to his writing. With a strong educational background, including a Master of Science in Engineering and a Bachelor of Science in Engineering, he has honed his skills and expertise through years of practical work. As a respected authority in the field, Mr. Hila is dedicated to offering insightful and valuable content that resonates with both vehicle owners and mechanics.

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  1. Anonymous says:

    Yes i have a 2008 Hyundai santa fe and well i was driving it then all of a sudden it shuts off like if to say i aint going no more i have checked my relays all fine but it seems like either no fuel or needs new fuel pump can someone please help

  2. Anonymous says:

    My engine light had been coming on for months. Sometimes it would go out. Car driving fine except once in a while, a misfire. I drove it to have it inspected and my car refused to start at all. Bought a new battery there and drove away from the place and no more engine light on. The diagnostics testing surely missed that one. The car is no longer missing either. Driving great and only a new battery.

  3. Anonymous says:

    Have a 2007 Hyundai sonata gls. Replaced the fuel pump one day later check engine light came on. Mechanic having problem locating reason. Car runs fine, just have light on. Never a problem until fuel pump replaced. Help!!

  4. Anonymous says:

    Engine check light is on but drives fine what the problem

  5. Anonymous says:

    Found this on a google search “To clear the Permanent DTC using a dedicated monitor cycle, start by repairing the fault that caused the DTC in the first place. Then clear all the codes except for the permanent DTC (if it were that easy, there’d be no problems), and make sure the Permanent DTC is the only one left.” Hope it helps.

  6. Anonymous says:

    I have a 2006 Hyundai Accent the problem I have is when I run the air the speed drops and I have replaced the 02 sensor and the spark plugs and the engine light went off for a while and came back on.

  7. Anonymous says:

    I have a 2010 Hyundai two years ago it coded p0440. Replaced gas cap, fixed it six months ago it came back again, replaced gas cap code 0440 again but this time check engine light stays on. It runs great but my emission test is due and I don’t know what to do.

  8. Anonymous says:

    my cel cal light came on , car runs fine but I was told the code was p1235. Its a 2013 sonata hybrid.

  9. Anonymous says:

    I have a 2007 imax petrol and the check engine light is on and now its blowing soot. no power at all. showing codes.po170 po107. help as I’m stuck in a country town in Western Australia full of hick mechanics that wouldn’t know if their arse is on fir.

  10. Anonymous says:

    Engine light comes on intermittently.code p0014 . Usally when fuel tank is 3/4 or 1/4 full . Refueling sometimes clears it . I have found adding a cap full of metho to a full tank wil. clear it .it has been to the dealer for 3 services but they do not appear to have rectified the problem or advised me of any issues. The obliviously clear the code for it to return later .
    The manual say it requires 91 octanes. Which I use . Have tried a higher octane but this did not change the situation .

  11. Anonymous says:

    have a check engine light on my 2007 sante fe 3.3l v6 and had two fault codes p0734 and p0738 it reads that it not properly shifting into gear do i need to change the transmission or is there and easier fix to the problem.

  12. Anonymous says:

    I have got an Hyundai Sonata 2006 V6 3.3L car and I am surprised after few months of using the car in Nigeria I noticed flashing on the CEL. When it was scanned it wrote p0300 random multiple cylinder misfire and p0018 crankshaft correlation bank 2 sensor A. My mechanic told me i have to pull out the engine and check the valves for repair or replacement. Kindly advice what do I do. My personal email is

  13. Anonymous says:

    I have got an Hyundai Sonata 2006 V6 3.3L car and I am surprised after few months of using the car in Nigeria I noticed flashing on the CEL. When it was scanned it wrote p0300 random multiple cylinder misfire and p0018 crankshaft correlation bank 2 sensor A. My mechanic told me i have to pull out the engine and check the valves for repair or replacement. Kindly advice what do I do. My personal email is

  14. Anonymous says:

    Remove the MAF sensor plug, than drive the car a few kilometers and see the behavior. If the car running better, replace the Maf sensor. During this time yours car will be in limp mode so that the RPM max will be 3000. Good luck!

  15. Anonymous says:

    My engine light blinked on twice when I try to turn on my air condition in the car

  16. Anonymous says:

    Get your inspection done at the dealer. If they can’t fix it they should pass it.

  17. Anonymous says:

    This was very very helpful!! Great, simple explanations for the not-mechanically inclined!!

    p.s. What about check engine light and slight vibration at low speed?

  18. Anonymous says:

    My Hyundai Getz 2008 just suddenly got the check engine light just like that not flashing or blinking and it drives fine

  19. Anonymous says:

    2008 Santa Fe with steady check engine light on. Code reader says oxygen sensor bank 1 . I have replaced both oxygen sensors and the old ones were tested good. Replaced spark plugs, fuel cap, intake manifold gaskets and much more, over $1000 spend with no joy. I cannot get it inspected now. They require I drive 50 miles after resetting. It comes back on after 30 miles. The car has 80.000 miles and runs perfectly.
    I understand Hyundai dealers have not been able to fix it either.

  20. Anonymous says:

    My hyundai santa fe, check engine light on while I’m on the high way

  21. Anonymous says:

    Why my check engine never goes on even the ignition switch is in on position

  22. Anonymous says:

    How to clear a permanent code p0011 please?

  23. Anonymous says:

    You need to read the codes as there are thousands of codes that could have triggered the light to come on.

  24. Anonymous says:

    CEL on and car cannot speed up..why?

  25. Anonymous says:

    Engine light is on. Drives fine. But when I Idil there is a rumble to the car.