How to Reset an Engine Warning Light

By Richard Toole

Seeing the engine warning light illuminated can be troublesome to a driver. For some drivers, it is cause for alarm. For others, it simply means a trip to the mechanic is needed. Sometimes the warning light illuminates because of a faulty wire or sensor in the light and not because the engine needs service. If you are sure there is no problem with your car, you can reset the engine warning light yourself and save yourself a trip to the garage.

Resetting your engine warning light may require you to work under the hood.

Disconnecting the Battery

Step 1

Pull the hood release lever inside your car. Open the hood.

Step 2

Disconnect the battery cables using an adjustable wrench.

Step 3

Turn on the headlights or press the horn button to drain any charge left in the electrical system. Wait 10 minutes. This should reset the engine warning light. Reattach the battery cables. Start the car and check the status of the engine warning light. (This method may not reset the engine warning light if your vehicle was produced after 1996.)

Using an Auto Scan Tool

Step 4

Purchase an auto scan tool to clear and reset the codes from your car's memory. Some auto parts stores will scan your car for free with its scan tool.

Step 5

Scan your car, either underneath hood or inside the vehicle next to the dashboard. The scan tool clears the engine warning light code that keeps turning it on. Wait several minutes.

Step 6

Start the car. Drive it for a few minutes. Turn the engine off.

Step 7

Start the car again. Check the status of the engine warning light. It may take a few drive cycles for the codes to reset.

Step 8

Repeat the process if the warning light is still illuminated. Drive the car for a short distance. Stop and turn off the engine. Depending on the car model and year, you may have to drive the car for longer periods before the engine warning light code is reset.