Patent ID: 7374600

Claim:
A method for avoiding back pressure faults in an engine control system, comprising: installing a new particulate filter in an engine exhaust system; setting a diagnostic message to a new filter installed status indication to indicate that the new filter was installed at a first operation duration value; comparing a current operation duration value to the first operation duration value after the diagnostic message is set to the new filter installed to determine if the current operation duration value is less than the sum of the first operation duration value and a predetermined duration value and providing a new filter indicator, if the current operation duration value is greater than the sum of the first operation duration value and the predetermined duration value and providing a normal filter status indicator; reading a sensed exhaust back pressure value from a sensor; setting a back pressure threshold value; determining whether the diagnostic message is set at the new filter status indicator and, if so, adding a new filter offset value to the back pressure threshold value to create an offset back pressure value; comparing the sensed exhaust back pressure value to the back pressure threshold value if the normal filter indicator is provided, or comparing the sensed exhaust back pressure value to the offset back pressure value if the new filter indicator is provided; and logging a high back pressure fault and providing an operator observable indicator signal if the sensed exhaust back pressure value is greater than the back pressure threshold value and the normal filter status indicator is provided or if the sensed exhaust back pressure value is greater than the offset back pressure threshold value and the new filter indicator is provided.