Circuit Description

The shift solenoids are two identical, normally open electronic exhaust valves that control upshifts and downshifts in all forward gear ranges. These shift solenoids work together in a combination of ON and OFF sequences to control the line pressure and shift mechanisms (clutches, brakes).

Solenoid 2 controls the high or low of the line pressure (flow to each clutch valve) by the operation type (ON/OFF), i.e. solenoid 2 is ON, line pressure will be low (87 - 116 psi [6 - 8 bar]), solenoid 1 is OFF, line pressure will be high (232 - 261 psi [16 - 18 bar]). Solenoid 2 controls the oil flow to clutch valve E or lock-up clutch valve by the ON/OFF signal.

The TCM monitors numerous inputs to determine the appropriate solenoid state combination and transaxle gear for the vehicle operating conditions.