PLATE 2755739 - Caterpillar

normal shifting, the ECM does not allow a turnaround shift for 2.3 seconds after a shift occurs. A turnaround shift is an opposite shift from the previous shift. For example, a downshift is prevented for 2.3 seconds after an upshift and an upshift is prevented for 2.3 seconds after a downshift. The turnaround shift time delay allows conditions to stabilize before an opposite shift. The delay prevents hunting between gears.The ECM overrides the turnaround shift time delay when the operator applies the brake or the retarder. Downshifts now occur immediately as a result of the decreasing transmission output speed. This function is provided in case the operator is required to make a sudden stop.The service brakes or the retarder brakes also provide elevated shift points in order to increase brake cooling.