How To Clear OBD2 Codes Without A Scanner

It’s easy to clear OBD2 codes without a scanner in just a few simple steps. It can be done in just a few minutes, and it won’t require any equipment, except for maybe a wrench.

How To Clear OBD2 Codes Without A Scanner

But what exactly are OBD2 codes and why should you pay attention to them?

OBD2 codes cause your check engine light turn on. This could indicate a wide range of problems, including minor issues with your gas cap or significant problems with your transmission.

Although you can clear an OBD2 code without a scanner, turning the check engine light off is not always the safest solution. If there is a serious problem that needs fixing, the light will come back on soon after you’ve turned it off. If this happens, then you should have your engine checked out by a professional to make sure that there isn’t a more serious issue.

Here’s how you can easily clear your car’s OBD2 codes.

Resetting OBD2 Codes

Resetting OBD2 codes without a scanner takes just a few simple steps. Here’s what you’ll need to do:

  • Make sure your car is parked in a level area, then pop open the hood.
  • Remove the (-) cable from the battery. You may need to use a wrench if it’s latched on tightly.
  • Perform the same procedure, but with the (+) cable. Always make sure that the two cables well away from each other.
  • Once you’ve removed the cables to the battery, you’ll need to cycle your ignition on and off. This should be done 2 to 5 times.
  • You’ll need to drain out any extra power that’s still left in the ECU. To do this, hold down on the horn on the steering wheel. The horn will use up any power that’s still in the circuit so that the ECU is fully drained. This can take anywhere from 30 seconds to a minute, so keep pressing down on the horn until it stops working.
  • Although you don’t have to, it’s best to wait a minute or so to reconnect the battery.
  • Clamp both of the cables back on the battery, starting with the red cable and then moving to the black one. As always, check to see that the clamps are tightly latched to the terminals.
  • Turn the engine on and check for any lights on the console. By the time your engine is warmed up, any warning lights should have turned off.

If the check engine light is still on once the vehicle is warmed up, you likely didn’t drain the ECU fully. Repeat the procedure, making sure to hold down the horn until the ECU is drained of all power.

Remember, simply unplugging your battery won’t be enough to clear OBD2 codes. This works on older cars that just use OBD1 codes, but most cars made after around 1996 will require the full process described above.

If the light comes back on within a day of clearing OBD2 codes, this is a sign that you need to get your car checked out for more serious problems.

Problems after Resetting OBD2 Codes

Although resetting OBD2 codes without a scanner is a fairly simple process, you might still notice a few minor issues once your car restarts.

This happens because you have to drain all of the power from the ECU to reset the codes. When power is restored, your car’s electronic settings will need to reboot. This might also mean that your clock, radio, and drive settings are reset.

In most cases, these issues aren’t much to worry about. Your car needs to reset to all of its settings after the ECU is drained. This can take at least one drive cycle, so don’t worry if your car isn’t acting right as soon as you turn it back on.

Them most common problem you might encounter is with the transmission. Since your car is rebooting all of its electronics, the shifting in its automatic transmission won’t reset perfectly right away. You’ll have to drive for a bit before it goes back to its usual state.

Some cars also built in modes that preserve your settings even if the ECU is drained of power. They use a memory device that stores these settings separately, so you always have a backup and the settings will load up automatically after the procedure.

What to Do If OBD2 Code Comes Back On

If you’ve reset the OBD2 codes without a scanner and notice that the check engine light is still on, this is a sign that there’s a serious problem that needs to get checked out by a professional.

Keep in mind that check engine lights aren’t just there to annoy you. If the light keeps coming back on, go get your car checked out.

You can easily check your car’s OBD2 codes yourself, but you’ll need an OBD2 scanner. They are widely available and affordable. They can help you find out what’s going on with your car so that you can get it checked out.


If you notice a check engine light, you might want to reset your OBD2 codes right away. Consider that though these warning lights are annoying, they are there for a reason.

Before you clear your OBD2 codes, you should do a quick check of your engine to make sure that everything is functioning as it should. You can also use an OBD2 scanner to see what the issue is if you have one lying around.

If you just want the warning light to go away, then follow the steps described above to quickly clear OBD2 codes and get the light turned off. The process takes just a few minutes, and it’s easy to do on your own.

Once you’ve cleared the codes, see if the light comes back on in the days following the procedure. If it does, don’t just clear out the codes again. You likely have an engine or transmission problem that needs to be checked out. Perform a systems check if you know how to or have a mechanic handle it for you.

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Check out other OBD2 codes:
U11E9 – What Does It Mean and How To Fix It
P059F Code – What Does It Mean and How to Fix It
P0500 Trouble Code

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