Things You'll Need

Instructions

1

Locate the diagnostic port on the driver-side dashboard underneath the steering column. On some Chevys you'll find the port by removing the fuse panel cover; on other '88 Chevys it's out in the open about knee high. In either case, the diagnostic port is the same size and shape as the connector on the OBD I scan tool. Plug the tool into this port.
2

Put the key into the ignition and turn it to the "on" position, but don't start the Chevy's engine.
3

Wait while the OBD I scan tool retrieves the codes. Write the codes it displays on its menu down on a piece of paper. Look up the meaning of the codes in the scan tool's manual.
4

Unplug the scan tool and turn off the vehicle. Have the Chevy serviced or repaired based on the information obtained from the codes.