OBD Operation Summary for 6.7L Diesel - MotorCraftService.com

Turbine Upstream Pressure Sensor Plausibility ChecksThe turbine upstream pressure sensor has plausibility checks to make sure that the sensor is not stuck in a range.If the ambient pressure is above a threshold, the monitor determines if there is warm or cold weather based onengine coolant and environmental temperature. In the case of high altitude or cold weather, the engine off timerand difference between the engine coolant and environmental temperatures are compared to thresholds todetermine if the pressure sensor may be frozen. At key-on the turbine upstream pressure sensor reading iscompared with the ambient pressure sensor reading, if the difference is greater than a calibrated threshold anambient offset error condition is flagged. If the sensor may be frozen, the engine is operated with reduced torqueuntil the sensor is determined to be in a thawed state. Once thawed, the turbine upstream pressure sensor iscompared with a modeled pressure under a calibrated window of engine speed and load. If the differencebetween the sensor and model is greater than a calibrated threshold, then a model offset error is present and amalfunction is detected. If an ambient offset error at start is present when the sensor is not frozen, then amalfunction is detected. If a model offset error is detected when the sensor is thawed, then a malfunction isdetected. Model offset error detection is not conducted under high transient mass airflow conditions, or at highaltitude.Turbine Upstream Pressure Sensor Plausibility Check Operation:DTCsMonitor executionMonitor SequenceMonitoring Duration for stuck midrangeP006D– Barometric Pressure Turbocharger/Supercharger InletPressure CorrelationP0471– Exhaust Pressure Sensor "A" Circuit Range/PerformanceOnce per driving cycleNone1.0 seconds to register a malfunctionDetection of a Frozen Turbine Upstream Pressure SensorFor Frozen Condition: Minimum MaximumEngine-off time (soak time)Engine Coolant TemperatureAmbient Air TemperatureAbsolute difference between Ambient Air and Engine CoolantTemperature480 min5 o C5 o C20 o CDetection of a Thawed Turbine Upstream Pressure Sensor for Model Offset Plausibility Check:Entry Condition Minimum MaximumRate of change of Mass Airflow100 kg/hr/secEngine Coolant Temperature50 o CAmbient Air Temperature5 o CEngine Speed 1500 rpm 3000 rpmEngine Torque 500 N-m 750 N-mFORD MOTOR COMPANY REVISION DATE: FEBRUARY 9, 2012 09.01.00.02-PAGE 84 OF 157