Clearing Fault Codes

It turns off the warning light if the fault has gone. It also resets readiness monitors. Codes return if the fault is still present. Clearing codes is part of a repair, not a repair in itself. Many inspection stations reject cars with too many incomplete monitors, so clearing just before a test is not helpful.

A scan tool sends a command to delete stored diagnostic data.

Record codes and freeze frame data first. A car with reset monitors may fail an emissions test.