These units are used to electronically position the throttle body valve opening (no cables from pedal to throttle body) according to input from the engine control unit. These units normally consist of: throttle body, throttle position sensor, electric motor, and sometimes electronic control circuitry.

Hitachi makes many types of engine control units, either printed circuit board or ceramic board (for higher temperature environments). The above unit is a water-proofed printed circuit board type ECU for engine compartment mounting (not for on-engine mounting).

This is an in-passenger compartment mounted transmission control unit. This automatically controls the transmission shifting sequence.