Clearing Diagnostic Trouble Codes

To clear the codes from the memory of the ECM, either to determine if the malfunction will occur again or because repair has been completed, the ECM power feed must be disconnected for at least thirty (30) seconds. Depending on how the vehicle is equipped, the ECM power feed can be disconnected at the positive battery terminal "pigtail", the inline fuseholder that originates at the positive connection at the battery, or the ECM fuse in the fuse block. (The negative battery terminal may be disconnected, but other on-board memory data, such as pre-set radio tuning, will also be lost)

Caution: To prevent ECM damage, the key must be "OFF" when disconnecting or reconnecting ECM power.

When using a hand-held diagnostic scanner, or "Scan" tool to read the codes, clearing the diagnostic trouble codes is done in the same manner as in the above procedure.