9-3 Hatchback (9400) L4-2.0L Turbo (B205) (2000)
/l4-2.0l_turbo_(b205)/Page-1087001.png)
Information Bus: Description and Operation
Description of Operation, Function Chains
Description Of Operation, Function Chains
In the bus system a large number of function chains can be identified. Below are three examples of important ones.
1. Vehicle speed
Description Of Operation, Function Chains
Vehicle speed is sensed by the ABS through an inductive sensor at each wheel. The sensor supplies the control module with alternating current, the
amplitude and frequency of which increase with increasing wheel speed. The frequency is proportional to wheel speed, 29 Hz at a speed of one wheel
revolution per second. The ABS control module uses the 4 wheel speeds to prevent wheel lock-up on braking
Several other systems in the car need to know its road speed. The ABS control module, which is not connected to a bus, therefore has a control module
output for each wheel. A transistor grounds the respective output 29 times per wheel revolution.
