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Brakes -- Basic Knowledge -- 215 & 220 Chassis: Specifications Mercedes-Benz Pullman W221

ASR drive torque control circuit, function - GF42.40-P-2100A

MODELS 129, 140, 202 as of 1.6.94, 163, 170, 208, 210, 220

with CODE (471a) Acceleration Slip Regulation (ASR)

with CODE (472a) Electronic Stability Program (ESP)

Acceleration slip regulation (ASR)

To achieve optimum traction if the drive torque is too high (wheel spinning) acceleration slip regulation is required. The acceleration slip reduction is controlled by an exchange of data via the CAN data bus between the installed ASR (N47-1) or ESP (N47-5) traction system and the respective injection and ignition system control module. With gasoline engines these control modules are: EAN4/1), LH-SFI (N3/1, N3/2, N3/3), HFM-SFI (N3/4) or ME-SFI (N3/10, N3/11, N3/12) and with diesel engines these control modules are: IFI (N3/7), DFI (N3/8) or CDI (N3/9).

  1. 4-cylinder gasoline engine with supercharger, 6, 8, and 12-cylinder gasoline engine: the EA (N4/1) or ME-SFI control module (N3/10, N3/11, N3/12) reduces the position of the throttle valve via the throttle valve positioner (M16/1 or M16/6) according to the accelerator pedal position specified by the driver and reduces the ignition timing via the HFM-SFI (N3/4), ME-SFI (N3/10, N3/11, N3/12) control module or the ignition control unit (N3/1).
  2. 4-cylinder gasoline engine without supercharger: The HFM-SFI control module (N3/4) cuts off the fuel supply.
  3. Diesel engine: The IFI (N3/7), DFI (N3/8) or DCI control module (N3/9) reduces the quantity of fuel.

The ASR or ESP control module (N47-1 or N47-5) continuously checks whether the control functions can be canceled owing to, for example, a sudden improvement in road grip so that the drive torque requested by the driver via the gas pedal can then be made available again.

MSR engine friction torque control

(not with 4 cylinder gasoline engine without supercharger)

The ASR or ESP control module (N47-1 or N47-5) detects if slip occurs at the drive wheels when the vehicle decelerates.

  1. 4-cylinder gasoline engine with supercharger, 6, 8, and 12-cylinder gasoline engine: The signal (throttle valve increase) is sent to the EA (N4/1) or ME-SFI control module (N3/10, N3/11, N3/12) via the CAN data bus. The calculated throttle valve opening is controlled by the control module (N4/1, N3/10, N3/11, N3/12) via the throttle valve positioner (M16/1).
  2. Diesel engine: The signal (increase fuel quantity) is sent to the IFI (N3/7), DFI (N3/8) or CDI (N3/9) control module via the CAN data bus. The fuel quantity injected is increased by the control module.

With this information, the drive torque can be changed so that no slip occurs at the drive wheels. This improves the lateral stability of the vehicle. This process occurs without notifying the driver (warning lamp A1e21 or A1e41).

Electronic acceleratorEngines 111, 112, 113, 119, 137 with ME-SFIGF30.20-P-3010E
Engine 120 with MEGF30.20-P-3010F
Fuel cut-off in ASR control mode, functionEngine 111.942/946/970GF07.51-P-3018G
Quantity control (DE)Model 210.017 diesel engine with electronic distributor injection pump (EVE)GF07.13-P-3163AC
Control of quantity and start of deliveryModel 210.004 diesel engine with electronic distributor injection pump (EVE)GF07.13-P-3004H
Quantity control (ERE)Model 210.010/020 diesel engine with electronic in-line injection pump (IFI)GF07.12-P-3015H
Quantity control (CDI)Engine 611 up to 5/99, engine 668GF07.16-P-3004I
Engine 611 from 6/99, engine 612GF07.16-P-3004IA
Engine 628GF07.16-P-3004IB