Clearing Diagnostic Trouble Codes

Use a scan tool to clear DTCs from the PCM memory. Disconnecting the vehicle battery will also clear the PCM memory, however most other system memories will also be cleared. This is generally undesirable. Disconnecting the PCM soley for clearing DTCs is not recommended since this unnecessarily disturbs the connections. Before clearing DTCs the scan tool has the capability to save any data stored with the DTCs and then display that data at a later time. Once a problem has been corrected and verified it is a good idea to clear DTCs so that any future service work is not needlessly confused.

Many DTCs have complex running and setting conditions. Therefore, simply clearing DTCs and watching to see if the DTC sets again may not indicate whether a problem has been corrected. To verify a repair after it is complete, you must look up the test conditions and duplicate those conditions. If the DTC runs and passes, chances are good that the problem is fixed.