Engine torque request

Fig 1: Engine Torque Request - Communication Diagram

Courtesy of SAAB-SCANIA OF AMERICA, INC.

Fig 2: Engine Torque Request - Circuit Diagram

Courtesy of SAAB-SCANIA OF AMERICA, INC.

The engine torque can vary between -100 N.m and +400 N.m. A negative value designates engine braking.

The TC/ABS control module sends the torque request to Trionic via the P-bus. This request can vary between +10 N.m and +400 N.m. When traction control is inactive the request is 400 N.m. Trionic uses this and other information to deliver the correct torque to the drive wheels. Refer also to the description of Trionic.

Engine torque is controlled by throttle control and ignition retardation. Throttle control is relatively slow compared with ignition retardation. By controlling engine torque rapidly it is not necessary for the system to brake as often or hard.