Exhaust Gas Recirculation (EGR) Low Flow System Monitor - Transit

The low or insufficient EGR flow is detected by the EGR systems inability to meet calibrated thresholds. The intake throttle will close partially to lower manifold air pressure to create more favorable conditions for EGR flow. The average intake throttle position can be monitored to detect a low or insufficient EGR flow concern.

When the entry conditions are met and remain met, the monitor averages the intake throttle position over a calibrated period of time. The time and averaging will pause if the entry conditions are no longer met, and resume when they are met again. When the monitoring time is achieved the monitor completes one event. The monitor will continue to run until a calibrated number of events has completed. The event counter increments up when an event is completed and the average throttle position during the event exceeds a threshold. The event counter increments down if the event completes and the average throttle position during the event is within the threshold, and the current count is greater than zero. A concern is detected when the event counter increments greater than a threshold and a DTC is set.