System Overview

Design and function
General

AW 30-40 and 30-43 are four-speed, electronically controlled automatic transmissions. Since each unit is controlled electronically with the aid of a transmission control module (TCM), gearshifting can be performed
to ensure that the correct gear is selected at all times to suit the current driving mode, engine load, driver's requirements, vehicle speed and other factors. This affords excellent fuel economy combined with high performance and enhanced comfort in terms of smoother operation and lower noise level.

The TCM is supplied with information describing the gear selected and the desired driving mode. Together with information on running conditions from a number of sensors, this is processed by the TCM to compute the optimum gearshifting and lock-up engagement points, depending on the driving mode selected.

The gear selector lever is connected mechanically to the transmission by means of a control rod. The driver can select different gearshifting programs by means of a driving mode selector beside the gear selector lever.