Speed, Lead From ABS

Speed, Lead From ABS

The ABS control module sends a speed signal to pin 64 of the Trionic T7 's control module. The signal is a square wave which varies between 0 V and B+ 29 times per wheel rotation. This speed signal is used to:
- determine, on manual gearboxes, which gear is used at the moment. This allows torque limitation in gears R and 1 and activation of the fuel shutoff in gears 2, 3, 4 and 5.
- activate speed limitation by limiting the maximum mass air flow/combustion at 240 km/h.
- prevent adaptation of idle speed control when the car is moving.

Diagnostics
- If there is no speed signal, diagnostic trouble code P0502 will be generated.
- The speed (bus from MIU) is used as a substitute value.

System reaction to a fault
Cruise control is blocked.