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. 

DIY Cost: 15-45
Est. Time: 15 min - 1 hour
Difficulty: Easy


What Does the Check Engine Light Mean on a Hyundai?

Check engine light on Hyundai Elantra Sonata Accent Santa Fe Sedona

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 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 technicians use 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 16-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.

    turn hyundai igntion on to diagnose check engien light on
  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.

    hyundai check engine light on clear codes
  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 is used to prevent 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 that problem, 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, that means that 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.

Replacing the spark plugs and spark plug wires is all you need to fix this problem.

In some cases, the check engine light may flash due to a bad ignition coil as well.

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 not accelerate at all.

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 both the check engine light and the ESC light come on, this means that the accelerator pedal position switch (eBay link) 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 (eBay link) is another possible solution.

Visitor, April 15, 2018
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
Visitor, April 15, 2018
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
Visitor, April 15, 2018
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.
Visitor, April 15, 2018
My hyundai santa fe, check engine light on while I'm on the high way
Visitor, April 15, 2018
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.
Visitor, April 15, 2018
Engine check light is on but drives fine what the problem
Visitor, April 15, 2018
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.
Visitor, April 15, 2018
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 .
Visitor, April 15, 2018
Engine light is on. Drives fine. But when I Idil there is a rumble to the car.
Visitor, April 15, 2018
CEL on and car cannot speed up..why?
Visitor, April 15, 2018
You need to read the codes as there are thousands of codes that could have triggered the light to come on.
Visitor, April 15, 2018
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!!
Visitor, April 15, 2018
My Hyundai Getz 2008 just suddenly got the check engine light just like that not flashing or blinking and it drives fine
Visitor, April 15, 2018
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.
Visitor, April 15, 2018
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.
Visitor, April 15, 2018
my cel cal light came on , car runs fine but I was told the code was p1235. Its a 2013 sonata hybrid.
Visitor, April 15, 2018
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?
Visitor, April 15, 2018
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
Visitor, April 15, 2018
Get your inspection done at the dealer. If they can't fix it they should pass it.
Visitor, April 15, 2018
Thank you
Hyundai Check Engine Light Stays On