EGR Flow Test Count
The scan tool range is 0 to 255. This indicates the number of
EGR flow test samples collected during the current ignition cycle. The maximum number of samples allowed is 1 during normal operation. If the PCM battery feed is disconnected or DTC P0401 is cleared, several EGR flow test samples are allowed during the next ignition cycle. This allows repair verification during a single ignition cycle.