How to Reset an OBD1 Computer

by Blaze Johnson

Beginning in the 1985, auto manufacturers incorporated the OBD1 computer system in certain passenger and light duty trucks. The on board diagnostic system monitors the fuel, emissions ignition and other related electronics components installed on the vehicle. The newer and more advanced OBDII system became the industry standard, beginning in 1996. After performing certain repairs to an OBD1-equipped vehicle, you may wish to reset the system. Resetting the on board diagnostics system will clear any resolved trouble codes present within the system.

Turn off the vehicle's engine and open the hood.

Disconnect the black-colored "Negative" battery terminal from the battery, using an appropriate size wrench.

Leave the battery terminal disconnected for at least one minute.

Reconnect the black-colored "Negative" battery cable to the battery, using an appropriate size wrench.

Start the engine and allow the vehicle to idle for five minutes. During the idling process, the engine RPM may fluctuate.

Drive the vehicle normally for approximately five minutes. Driving the vehicle will allow the computer system to readjust the operating parameters.

Park the vehicle and check for proper radio operation. If the radio has an anti-theft option, unlock the radio using the instructions provided within the owner's manual.

Items you will need

About the Author

In the spring of 2008, Blaze Johnson decided to share his expertise through writing. He studied business administration at a local community college and runs his own driveway mechanic service, specializing in computer-controlled vehicles and custom car audio installs. Johnson also serves as the de facto computer repair person for his family, friends and coworkers.