How to Reset the Codes on Vehicles

by Contributing Writer; Updated June 12, 2017

Error codes in a Vehicles Motors Vehicles will appear because the Vehicles is having some sort of mechanical or electrical problem that needs your attention. The error codes trigger your error lights, such as you check engine light, to come on in the dash and alert you to the problem so that you can repair the Vehicles. However, the error lights in many Vehicles do not automatically turn off after you have repaired the original problem. Many Vehicles require you to reset your Vehicles computer or erase the codes manually in order to make those pesky error lights and codes go away.

Under The Hood:

 How to Reset the Codes on GM Cars

Vehicles Manufactured Prior to 1996

Open the hood of your car. Locate your battery.

Disconnect the battery cable that is attached to the negative terminal, then disconnect the battery cable that is attached to positive battery terminal. Do not let the cables touch each other or the car while the battery is still attached.

Let the car sit for 30 minutes. This will make sure the computer resets.

Reattach the battery cables, positive first and then negative. Turn on the car. If you fixed the problem prior to resetting the car battery, then your error codes will have been erased and your error lights should have turned off.

Vehicles Manufactured After 1996

Hook your GM car up to an automotive code reader. Scan for codes.

Electronically erase codes using the code reader. The exact process for doing this will vary depending on the make and model of your code reader, but all code readers have an erase/delete function.

Remove the code reader from the vehicle, allow it to sit for several minutes and then start the car. If the codes were properly erased and the problem no longer exists, your error lights will be off and the codes will no longer come up when you can your car's computer.

Items you will need

  • ¾ inch wrench

  • Code reader

 How to Reset Codes on a 1998 Chevy S10 Blazer

Open the driver's-side door of the Blazer and locate the data/diagnostic link connector (DLC) under the driver's-side dashboard. It is tucked up underneath the dash near the parking brake pedal to the left of the steering column.

Connect the plug of the scanner to the DLC.

Turn the ignition key to the "ACC" power position to illuminate all the instrument cluster lights, but without the engine running.

Press the "Erase" button on the scanner, if it is equipped with one. If not, some scanners may require scrolling through the onscreen menu display with an up or down (or both) scroll button(s). Scroll to the erase codes option (it may say "erase DTCs" for "diagnostic trouble codes") and press the "Enter" button. Toggle to the "Yes" option with the scroll button, if applicable, and press the "Enter" button again. Wait until the scanner defaults to the main menu or the onscreen display confirms "Command Sent."

Start the engine and look for the "Service Engine Soon" light on the instrument cluster. If the light is still there, repeat the process. If the light remains there after the second attempt, the Blazer most likely has a "hard" trouble code that needs to be diagnosed and serviced as soon as possible.

Items you will need

  • Scanner (OBD II)

 How to Reset Codes in a Chevrolet Duramax

Plug your OBD-II code reader into the port on the bottom of the driver’s side dashboard. The port and the code reader’s plug are both trapezoid shaped.

Put the key into the ignition and turn it to the “ACC” position. This should power on the code reader. If not, turn on the code reader.

Select the “Read” command on the code reader, then select “Delete.” Wait for the code reader to indicate that the command has been completed. This is usually indicated by returning to the main menu.

Remove the code reader from the port and turn the engine on. Verify that all service and warning lights have shut off.

Items you will need

  • OBD-II code reader

  • Ignition key

 How to Reset Codes on a Toyota

Locate the vehicle's OBD-II port on the driver's side dashboard near the fuse panel cover. The port should be the same size and shape as the connector end of your OBD-II reader. An OBD-II reader is a small, hand-held, computerized device that you can purchase from your local auto parts store.

Plug the reader into the port. Put the key into the ignition and turn it to the "II" position, but do not start the engine. Wait while the vehicle's electrical system powers on the OBD-II reader.

Find the "Delete Codes" command on the reader, or a similar command. Commands vary between readers, depending on its manufacturer. Select the command and wait for the "Command Sent" message to display or until the main menu reappears on the device.

Unplug the reader and start the vehicle's engine. Verify that all warning and service lights have shut off on the instrument cluster. The computer has been reset and the codes have cleared.

Items you will need

  • OBD-II reader

  • Ignition key

 How to Reset Codes for the 2002 Chevy Tahoe

Park the vehicle and turn off the ignition. Pop up and secure the vehicle's hood and find the battery.

Loosen the nut on the negative battery cable with the adjustable wrench. The negative cable is black and marked with a "-" sign. Slip the clamp off of the negative battery terminal and do not to let it touch anything metal, especially the positive battery terminal.

Wait 30 minutes while the Tahoe's computer resets.

Put the negative battery cable back in place and tighten the nut with the adjustable wrench.

Put the key into the ignition and start the vehicle's engine. Verify all warning and service lights have shut off. Drive the vehicle. It will take a few trips for the computer to reset and get in sync with all of the vehicle's functions.

Items you will need

  • Adjustable wrench

  • Ignition key

About the Author

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