OBD Operation Summary for 6.7L Diesel - MotorCraftService.com

Diesel Particulate Filter Pressure Sensor Rationality TestThe DPFP Sensor is checked continuously for proper circuit continuity, rationality, and expected dynamic behavior.The rationality test compares the raw DPFP value in engineering units to a threshold, with the expectation thatthere will be a minimum pressure observed whenever sufficient exhaust flow is present. An additional rationalitytest compares the measured change in DPFP to an expected change, which is based on changing exhaust flows.If exhaust flow is increasing, the change in DPFP is expected to be increasing. If exhaust flow is decreasing, thechange in DPFP is expected to be decreasing. The dynamic test runs continuously as long as exhaust flows aresufficiently dynamic. The fault threshold in kPa is a function of changing exhaust flow.Diesel Particulate Filter Pressure (DPFP) Sensor Circuit Check:DTCsMonitor ExecutionMonitor SequenceSensors OKTypical Monitoring DurationP2454 – DPFP Sensor Circuit LowP2455 – DPFP Sensor Circuit HighContinuousNoneNot applicable2 sec.Typical Diesel Particulate Filter Pressure Sensor Circuit Check Entry Conditions:Entry Condition Minimum MaximumBattery Voltage 8v 15vKey OnTypical Diesel Particulate Filter Pressure Sensor Circuit Check Malfunction Thresholds:Voltage < .10 volts or voltage > 4.90 voltsThe DPFP sensor is a single port gauge sensor that provides an analog output voltage that is proportional topressure and is typically used before and after a DPF (Diesel Particulate Filter) to monitor the differential pressure.DPFP Sensor Transfer FunctionDPFP volts = 0.082 * kPaG Delta Pressure) + 0.45Volts A/D Counts in PCM Delta Pressure, kPa Gauge0.10 20 -4.30.45 92 01.27 260 102.09 428 202.91 595 303.73 763 404.55 931 504.90 1003 54.3FORD MOTOR COMPANY REVISION DATE: FEBRUARY 9, 2012 09.01.00.02-PAGE 111 OF 157