Speed, Bus From TC/ABS

Speed, Bus From TC/ABS










The TC/ABS control module sends the bus message "Wheel speed, front right, XXX km/h" via the P-bus to the Trionic control module connections 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 by limiting the maximum air mass/combustion at 240 km/h on B205E/L/R and 250 km/h on B235R.

Diagnostics
- If the speed message is missing, diagnostic trouble code P0502 will be generated.
- If the speed value is implausible, diagnostic trouble code P0501 will be generated.

System reaction to a fault
- Speed (bus from MIU) used as substitute value.
- Cruise control blocked.