Basic function of automatically controlled all-wheel drive

Overview

This document contains information on:

 General

 Function

General

In comparison to the front or rear wheel drive, the all-wheel drive forwards the drive force to all wheels. Traction increases and improved off-road capability is achieved.

In contrast to the front or rear wheel drive, the drive force is forwarded to all wheels.

Function

Automatically controlled all-wheel drive on vehicles with transversely mounted engine and dual-clutch transmission

The power take-off distributes the torque to the rear axle and is integrated into the dual-clutch transmission. The torque is output to the rear axle variably depending on the driving situation and the wheel slip of the front wheels. The power take-off compensates differences in rpm between the front and rear wheels which occur in all-wheel mode while cornering.

Depending on the following situations, torque is distributed to the rear axle:

 Dynamic cornering

 Wide open throttle acceleration

 Extremely varying road surfaces

Automatically controlled all-wheel drive on vehicles with longitudinally mounted engine and automatic transmission

In the case of vehicles with longitudinally mounted engine and transmission, the torque distribution is predefined by the transfer case. Active-selective brake application takes over the function of the differential lock and vehicle dynamics control. The automatically regulated all-wheel drive is usually a permanent all-wheel drive with fixed force distribution.