Maximum permissible torque

Fig 1: Identifying Communication Diagram (1 Of 2)

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Fig 2: Identifying Communication Diagram (2 Of 2)

Courtesy of SAAB-SCANIA OF AMERICA, INC.

In order to achieve smoother gear changes and minimal transmission wear, the TCM continuously sends information on the bus to the engine control system about the "maximum torque" in Nm.

As the transmission is constructed to withstand a maximum torque of 350 Nm (B235), 310Nm (B235E, B308E) and 280 Nm (B205E, D223L), the TCM normally transmits the bus information "Maximum torque 350/330 Nm" but during certain gear changes, especially during hard acceleration, the TCM requests a lower "maximum torque" during the short gear change interval.

The engine control system uses the information for torque limiting via air mass control.

Fig 3: Connection Diagram

Courtesy of SAAB-SCANIA OF AMERICA, INC.