ASC drive torque control circuit, function - GF42.40-P-2100F

MODEL 463.243 /244 /246 /247 /249 /250 /254 ## as of 127357 as of 1.9.01, 463.270 /271, 463.309 /322 /323 /332 /333 ## as of 127357 as of 1.9.01 with CODE (BB3) Electronic Stability Program (ESP) 

MODEL 463.248 ## as of 127357 as of 1.9.01 with CODE (BB3) Electronic Stability Program (ESP) except CODE (979) Special protection version 

Fig 1: Identifying ASC Drive Torque Control Function Diagram

Courtesy of MERCEDES-BENZ USA

1. Detecting and processing sensor signals and switch conditions 

   The ESP and BAS control unit (N47-5) reads in the CAN messages of the following components via the CAN data bus and evaluates them:

   1. 1.1 ME-SFI control unit (N3/10) or CDI control unit (N39/2) 
      • CAN message "engine torque" 

        Capture the engine torque, required to determine a reduced engine torque.

      • CAN-message "accelerator pedal position" 

        Determine the accelerator pedal position, which is used to work out the engine torque requested by the driver.

   2. 1.2 ETC [EGS] control unit (N15/3/) 
      • CAN message "transmission ratio" 

        Determine which gear is currently engaged. The information is required to calculate the driving power acting on the drive gears and to control the drive moment.

2. Activation and deactivation of drive torque control 
   • After evaluating the information it has read in, the ESP and BAS control unit (N47-5) activates the drive torque control if a traction status occurs in which the drive torque specified by the position of the accelerator pedal is too great.
   • The control is deactivated as soon as the traction condition of the vehicle permits the drive torque specified by the driver.
3. Computation and transfer of drive torque 

   The ESP and BAS control unit (N47-5)

   • calculates the specified value for the drive torque (reduced engine torque) for each control interval
   • and passes a relevant CAN message to the ME-SFI control unit (N3/10) or the CDI control unit (N39/2).