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 [1][2]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.