OBD Operation Summary for Fiesta - MotorCraftService.com

The diagnostic executive controls the setting and clearing of permanent DTCs.A permanent DTC is stored when a confirmed DTC is stored, the MIL has been illuminated, and there arenot yet six permanent DTCs stored.After a permanent DTC is stored, three consecutive confirmed fault-free monitoring cycles must occurbefore the permanent DTC can be erased.After a permanent DTC is stored, one confirmed fault-free monitoring cycle must occur, following a DTCreset request, before the permanent DTC can be erased. For 2010MY and beyond ISO 14229 programs adriving cycle including the following criteria must also occur, following the DTC reset request, before apermanent DTC can be erased:oooCumulative time since engine start is greater than or equal to 600 seconds;Cumulative vehicle operation at or above 25 miles per hour occurs for greater than or equal to300 seconds (medium-duty vehicles with diesel engines certified on an engine dynamometer mayuse cumulative operation at or above 15% calculated load in lieu of at or above 25 miles per hourfor purposes of this criteria); andContinuous vehicle operation at idle (i.e., accelerator pedal released by driver and vehicle speed lessthan or equal to one mile per hour) for greater than or equal to 30 seconds.A permanent DTC can not be erased by a battery disconnect. Additionally, its confirmed DTC counterpartwill be restored after completion of the system reset (battery reconnect).CONTINENTAL REVISED: SEPTEMBER 17, 2010 PAGE 107 OF 111