Speed, bus from TC/ABS/ESP: Notes

WARNING: This page is about a different car, the 2004 Saab 9-5. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Speed, Bus From TC/ABS/ESP

Courtesy of SAAB-SCANIA OF AMERICA, INC.

Fig 2: Speed, Bus From TC/ABS/ESP Circuit Diagram

Courtesy of SAAB-SCANIA OF AMERICA, INC.

The TC/ABS/ESP control module sends bus message "Wheel speed, front right, XXX km/h" via the P-bus to the Trionic control module connection 19 and 66. This speed signal is used to:

prevent adaptation of idle speed control when the car is moving.
on manual gearboxes, determine which gear is currently being used. This makes it possible to limit torque in gears R and 1 and activate fuel shut-off in gears 2, 3, 4 and 5. Control of the SHIFT UP lamp also depends on the current gear.
activate speed limitation, which is achieved by limiting the maximum air mass/combustion at 240 km/h for B235E and 250 km/h for B235R.