How to Clear the Codes on Vehicles

by Contributing Writer

Engine codes in your Vehicles can be triggered by a number of issues, ranging from big to small. Anything from a loose gas cap to major problems such as an engine misfire can cause the check engine light to go on. In order to check these codes, you'll need an onboard diagnostics scanner. There are two different versions, depending on your model. After the problem is fixed, the codes will need to be cleared out of the car's computer, which can quickly and easily be done once the battery has been disconnected and then reconnected.

Under The Hood:

 How to Clear the Codes on a Toyota

Turn the vehicle off.

Open the hood and locate the battery. It will be in different locations depending on your particular Toyota make, model and year. However, it will be located in one of the four corners of the engine compartment.

Place the adjustable wrench around the bolt that secures the negative battery clamp to the battery.

Adjust the wrench until it fits snugly around the bolt.

Loosen the bolt on the clamp until you can easily remove the negative battery clamp.

Wait between 30 and 60 seconds.

Put the negative battery clamp back on the battery and tighten it with the adjustable wrench.

Start the vehicle to see that the check engine light is off.

Items you will need

  • Adjustable wrench

 How to Clear Codes on a Ford

Plug the code scanner into the data port, which is located under the dash and just to the left of the steering column.

Turn the key to the “On” position. Press the “Read” button on the scanner. The scanner will read the codes and flash them on its screen. Write the codes down.

Match the codes with the code sheet that comes with the scanner. The codes are usually in the form of a letter plus four numbers. The code sheet translates the codes into something understandable.

Repair the problem sensor or sensors. If the code scanner shows several codes that don’t seem to make sense – a coolant temperature sensor, when you know the vehicle is not overheating, a MAP sensor and the idle air sensor when the vehicle idles fine and doesn’t stall out, the computer could be suspect. If the computer is malfunctioning, the codes will not clear unless the computer is replaced.

Plug the code scanner into the data port. Turn the ignition to the “On” position. Press the “Erase” button to clear the codes.

Items you will need

  • Code scanner

 How to Clear Codes on a Sterling Truck

Remove the fuse panel cover. Pull down on the cover to remove it.

Plug the pinned connector on the diagnostic reset tool into the fuse panel input for the reset tool.

Turn the ignition key to the "II" position and wait for the light on the tool to stop flashing. When it does, all of the codes will be reset.

Items you will need

  • Sterling diagnostic reset tool

 How to Clear Codes From a Jeep Grand Cherokee

Pop the hood on the Jeep Grand Cherokee by lifting the lever under the dashboard.

Release the lever under the front of the hood, and lift up the hood.

Locate the battery. It will be on the passenger's side, directly behind the headlight.

Place an adjustable wrench around the bolt that is securing the negative battery clamp.

Adjust the wrench until it fits tightly around the bolt.

Loosen the negative battery clamp, and remove it.

Hold the negative battery clamp away from the battery and wait one minute.

Place the negative battery clamp back onto the negative battery terminal.

Tighten the clamp until it is securely on the negative battery terminal again.

Start the Grand Cherokee.

Verify that the "Check Engine" light no longer is on.

Items you will need

  • Adjustable wrench

 How to Clear Codes on the 2002 Corvette

Turn the ignition key to the "ON" position but do not start the engine. Press the "RESET" button to turn off any warning messages that may be displayed on the driver information center. The control buttons for the driver information center can be found on the right edge of the instrument cluster in the 2002 Corvette.

Press and hold the "OPTIONS" button. While holding the button down, press the "Fuel" button four times within ten seconds to enter into the diagnostic mode. Wait while the computer cycles through all of the diagnostic functions automatically and displays related codes.

Press the "RESET" button to clear all codes. Press the "E/M" to exit the diagnostic mode.

 How to Clear the Codes on a Ford F-150

OBD I

Under the hood of your Ford F-150, loosen the black (negative) battery terminal clamp with a hand wrench and wiggle the clamp off the terminal.

Wait five minutes.

Reconnect the clamp to the battery post and tighten the clamp with a hand wrench.

Start the Ford F-150 to ensure the check engine light is no longer illuminated.

OBD II

Locate the diagnostic link connector (DLC) beneath the driver's side dashboard.

Plug the pocket scanner into the DLC and turn the ignition key two clicks to the key on/engine off position.

Follow the procedures for the pocket scanner to erase the codes. There are now many affordable pockets scanners on the market that employ slightly different procedures. Most employ a scroll button or two that will allow you to position the on-screen cursor to a desired selection. Once you've scrolled to the erase code selection, pressing the enter key is all that's required. There may be a few seconds while the scanner sends the command to the F-150's computer.

Start the engine to ensure the malfunction indicator light is no longer illuminated.

Unplug the pocket scanner and turn off the truck.

Items you will need

  • Hand wrench set

  • Pocket scanner code reader/eraser