How to Reset Your Check Engine Light

Check engine lights are known to be triggered for minuscule reasons that do not hinder your vehicle’s performance. No matter the reason the light is being triggered, it will keep you from passing emissions testing in your state. Refer to this simple guide to learn how to reset your check engine light, and how to determine whether the issue is serious or not.

OBDI

Resetting Procedure

Notice: Before resetting your check engine light, it is recommended to learn the code your vehicle’s computer is relaying to trigger the check engine light. Most makes and models produced before 1995 have their own particular methods for retrieving codes. Once obtained, write it down for future reference.

1. Disconnect the positive (red) cable from the battery terminal. Leave the wire disconnected for five minutes.

2. While the battery is disconnected, turn your vehicle’s ignition to the “ON” position three times.

3. Make sure your vehicle’s ignition is turned off, and reconnect the positive cable to the battery terminal.

4. Once the battery is reconnected, turn the ignition to the “ON” position for one minute, and then start your vehicle. The check engine light or “service engine soon” light should have reset and shout not appear on your gauge cluster.

Notice: If your service light does not come back on, it means your vehicle’s computer has not stored emission data and all data pertaining to your vehicle’s engine and emission system has been deleted, and sometimes includes security and radio settings.

5. Take your vehicle for a test drive to ensure the light does not occur again. If it does, obtain the code and diagnose the problem as the light is being triggered because there is a reoccurring problem.

OBDII

Resetting Procedure

Notice: Unlike OBDI systems, it is not safe to disconnect the battery to reset the check engine light on vehicles made after 1995. You will need a OBDII scanner tool to reset the check engine light due to your vehicle's body control modules and their need for constant 12-volt power.

1. Obtain an OBDII scan tool. They can typically be purchased at any auto parts store for a reasonable price, or some auto parts stores offer free diagnostic scanning services.

2. Once you have a scan tool, connect the scanner to the OBDII port under your vehicle’s steering column, and then turn your ignition to the “ON” position.

3. Select the “read” button on the scanner to view the engine code(s.) Once you’ve learned the codes, determine if it’s a reoccurring issue that needs to be addressed.

4. Select the “erase” button on the scanner to clear the code(s) and turn off the check engine light from your vehicle’s gauge cluster.

If you own an OBDII vehicle, it is recommended to get a scan tool as they’re fairly cheap and can rid your vehicle of any codes that were set off due to the emission system's sensitivity, while also making it possible to diagnose severe issues easily. For OBDI issues, if check engine lights continue to be triggered, it is best to source wiring guides to address frequently occurring issues.