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Speed, bus from ESP

Speed, bus from ESP



The ESP control module sends the bus message "Wheel speed, FR, XXX km/h” via the P-bus to ECM. This speed signal is used to:


• Determine the gear currently engaged. This ensures the engine receives the correct fuel quantity in different gears when the accelerator is released by measuring the road speed and engine speed.

• Give impulses to cruise control.


Diagnosis


• If the speed value is implausible, DTC P0501 will be generated.

• If the speed signal is low, DTC P0502 will be generated.

• If the speed signal is high, DTC P0503 will be generated.


System reaction to a fault


• The control module uses 0 km/h as a substitute value.

• Cruise control blocked.