Solenoid and Pressure Switch Assembly

When the Transmission Control Relay contact points are closed, the solenoid assembly receives electrical power. The TCM can then operate the solenoids, as determined by its programming. The relay provides power to all four solenoids through a single wire. This means that all the solenoids have voltage supplied to them whenever the Transmission Control Relay is closed. The solenoids, however, are not energized until the TCM grounds the solenoid return wire for the solenoid that is needed.

The assembly is mounted to the outside of the transaxle case, under a sound shield protective cover, toward the front of the vehicle. There are two gaskets that seal the solenoid pack to the steel plate. There are also small solenoid valve filters used to protect the valves from contamination. These filters are not replaceable. If the valve body and solenoid pack have been heavily contaminated, the solenoid pack should be closely inspected to determine if it should be replaced. The solenoid pack is not a serviceable unit.

The Solenoid and Pressure Switch Assembly is supplied voltage by the Transmission Control Relay. The assembly consists of four solenoid/valve assemblies that control hydraulic pressure to four of the five clutches in the transaxle and the torque converter clutch. A unique feature of the solenoid/valves is that they directly control the application of a clutch. In other electronically controlled transaxles/transmissions, the clutches are indirectly controlled by the solenoids through normal hydraulic valving. The solenoid assembly also contains pressure switches that feed information to the TCM.