What does a Pull/Clear CEL code or check engine light mean?

The check engine light or CEL codes indicate there is an issue with your car. It is trying to tell you that it needs help. Pulling or connecting a scan tool to retrieve information of the stored diagnostic trouble code will help a professional technician determine the proper steps to fix the problem. Once the repair has been resolved, clearing the stored trouble code and making sure the light doesn’t come back on will confirm the repair has been completed.

Keep in mind:

Check Engine Light (CEL) diagnosis became more standardized in the U.S. in 1996 it was mandated a universal port connector and a list of diagnostic trouble codes to be provided in all cars sold in the US under a protocol called OBD-II or On-board Diagnostics-II. Location of the OBD-II Connector is to be located within 2 feet (.61 m) of the steering wheel (unless an exemption is applied to the automaker, which will still be required to be in reach of the driver seated). The Check Engine Light can be orange or yellow, but if the CEL is flashing then it can indicate a serious issue occurring and should be addressed immediately. The CEL illuminated will automatically fail an emissions inspection in smog regulated areas. It’s important to take any illuminating malfunction indicating light seriously, as they can indicate an overheating or failed electrical engine component, that may lead to a fire. The CEL may store codes that indicate any number of issues such as faulty ignition coils, thermostat, fuel injectors, catalytic converters, oxygen sensors, spark plugs, or any number of issues.

How it's done:

A professional technician will use his/her OBD-II Scanner and scan and retrieve stored codes in the engine’s computer. Once codes have been identified, following a pinpoint guide step by step under a diagnostic program or service manual. Performing the necessary repairs on the vehicle Clearing the code and test driving the vehicle confirming the check engine light doesn’t return

Our recommendation:

Avoid ignoring the check engine light. Some people actually put black tape over the sign, which is of course the opposite of a solution. The light could mean something minor that can wait, or it could be something that’s urgent and even life threatening. Unfortunately without a diagnostic, there’s no way to know. Generally, a minor fix unattended will lead to more costly repairs in the future.

What common symptoms indicate you may need to check the code?

  • Abnormal engine noises may include clicking, ticking, grinding, popping, or humming.
  • Abnormal odors, burning smell from engine or tail-pipe, rotten egg smell when accelerating, or smell of raw fuel or gasoline.
  • Oil leaks, fluid leaks found on the floor after the vehicle has been parked for just a few hours.
  • Check gauges, engine temperature, oil pressure, battery voltages readings may be too high or too low.
  • The CEL has been flashing or intermittently going on/off while driving.
  • Poor fuel economy, loss of engine power, engine surging or hesitation, vehicle stalling, long cranking, or any other drivability concerns.
  • Won’t pass emissions.

How important is this service?

Getting the check engine light decoded can be an annoying undertaking when it comes on suddenly because you may be in the middle of something and the last thing you want to do is call a mechanic. But it’s one of those situations where it’s better to be safe than sorry.


The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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