Method for actuating drive strand of motor car during fail-safe operation of gear box, involves limiting drive torque by drive unit if ratio between rotation speed of drive unit and rotation speed of gear unit changes

摘要

The method involves arranging a friction clutch arrangement (14) between a drive unit (12) i.e. combustion engine, and a shift gear (16). The drive unit is controlled by an engine control unit (28), and a gear unit (13) is controlled by a transmission control unit (26). A friction clutch of clutch arrangement is closed during a fail-safe operation of a gear box. A delivered drive torque (Mm) is limited or reduced by the drive unit if a ratio between a rotation speed (nm) of the drive unit and a rotation speed (na) of the gear unit changes.