How to Reset the Check Engine Light

Cars are equipped with electrical systems that monitor how the car is working. When something's wrong, a little light comes on your dashboard that says "Check Engine." Below are a few things you can do to reset the check engine light.

  • Fix the problem triggering the light If your check engine light came on, the computer detected a problem that needs fixing. If you don't know how to check the codes from the computer and how to repair your car on your own, bring your car to a professional mechanic and have it fixed. Once the problem is resolved, the check engine light will go off and stay off [source: RepairTrust].
  • Have a professional reset the on-board diagnostics computer If you just don't want to fix your car, and you don't want to deal with the complications of a hard reset, you can have someone with a Check Engine Light Code Reader reset the tripped code. You can ask someone at your local service center to reset the computer without charging you for diagnostics. Many auto parts stores also have this machine and will perform this task free of charge if you ask nicely [source: RepairTrust].
  • Do a hard reset If you don't want to try either of the above options, you can reset your check engine light the hard way. Disconnect the car battery. The on-board diagnostics require some power to save the memory of the fault codes it's picking up to trigger the check engine light. Leave the lights on and press the horn for several minutes to drain the last bit of electricity. The downside of this method is that you will lose all the data from the computer. Also, your check engine light is likely to come on again once the computer comes across the problem that tripped the check engine light in the first place [source: Gittelman].