Valve Body Solenoid Power

Valve Body Solenoid Power

TCM Internal Relay:





The transmission valve body is provided a power circuit for solenoid (MV) and pressure regulator (EDS) operation. The configuration of the circuit is dependent on the transmission model.

Example: The ignition key is switched on causing the DME to activate the ECM Main Relay. The TCM receives operating power as discussed in the inputs section.

The TCM activates an internal relay which either provides a ground as in the case of the A4S 310R or provides power to the solenoids of all the other models.

A4S 310R: The A4S 310R requires five solenoids for operation. These include, two shift solenoids, 1 band brake solenoid and a torque convertor lock-up solenoid. These are supplied with a common switched ground from an internal relay within the TCM. They are energized as required by switched power final stage controls (MV 1, 2 & TC Lock) and by PWM control (Band Brake).

The pressure regulator solenoid is the fifth solenoid. It is supplied with power from the EGS control unit module, and energized by a pulse width modulated ground.

All other transmissions: The balance of the systems covered in this course have numerous solenoid valves and pressure regulators.

They are supplied with a common switched power supply from an internal relay within the TCM. They are energized as required by switched ground final stages and PWM control.