The primary/secondary steering pressure switches, attached to the secondary steering valve, send pressure information to the transmission ECM. The secondary steering motor and pump will be activated by the transmission ECM when the primary steering pressure switch senses a loss of oil pressure and the drive shaft speed is greater than 50 rpm. The secondary steering motor and pump will be deactivated by the transmission ECM when the main steering pump oil pressure increases to 700 ± 100 kPa (100 ± 15 psi) or when the machine ground speed decreases to zero.