Sheeet this is an old thread. But for the sake of "know" I'll reply.
So, ASR (Anti-Slip Regulation or Antriebsschlupfregelung) does not apply the brakes EVER, ....
Sorry, but in the interest of correctness, ASR
DOES apply brakes when required.
Full description of ASR, according to elearn:
Description ASR
This system carries out all the normal anti-lock and brake distribution functions (EBD) of the ABS 5.7 with EBD and also ensures the following:
- Acceleration Slip Regulation (A.S.R.)
- engine braking torque regulation (M.S.R.)
- differential lock via action on the brakes (T.C.)
The functions are ensured by adjusting drive torque and applying a braking force to one or both drive wheels.
If one or both drive wheels tend to slip during acceleration, the control unit orders the engine control unit to reduce the torque transmitted by the engine to the wheels and almost simultaneously brakes the wheel or wheels without the driver having to do anything.
If the wheels tend to lock during hard deceleration, the ABS control unit requests the engine control unit to adjust engine braking toruqe to prevent car stability.
The system can be cut out by activating a button located on the console.
A led comes on on the button and a message is displayed on the instrument panel DOT matrix to indicate deactivation of the ASR/MSR.
The button warning light comes on and the DOT matrix message is repeated to indicate system cut-out due to a fault recorded by the control unit.
ASR/MSR intervention is indicated by the warning light on the dashboard flashing.
Each time the vehicle is started up the ASR/MSR function is activated, even if the ignition has been turned off with the function deactivated.
The system processes the signals coming from the active sensors, the brake light switch and the button for switching the A.S.R. function on/off.
It continually compares the speed of wheels on the same side of the car (Front right with Rear right - Front left with Rear left) and causes the ASR to cut in when a speed difference in excess of 2-6 km/h (cut-in threshold) is detected between wheels on the same side. The control unit turns on the MSR function when it detects an excessive difference between the front and rear axles because the front wheels tend to slow down too much compared to the rear wheels.
The ABS/ASR control unit communicates continuously with the engine control unit via the C-CAN line.
The ASR function is active under all car speed conditions. Braking action is cut out after 80 km/h.
Operating strategy
Drive wheel slippage
Intervention - intervention times in road conditions with good grip (asphalt)
Torque reduction by the engine control unit by altering ignition advance - 6/100 s after the skid threshold is exceeded;
Further torque reduction by reducing throttle opening (by the engine control unit with motorized throttle body) - after 15/100 s;
Hydraulic system intervention (braking force on drive wheel) - after 2/10 s.
Operation under conditions of poor grip
The system is able to detect this situation by comparing drive wheel acceleration with torque transmitted by the engine (engine load via engine control unit).
The system performs in the same way as when both drive wheels are in road conditions with good grip (asphalt) and the cut in thresholds are at the lower limit.
Only one drive wheel slipping.
Intervention-intervention times
Torque reduction by the engine control unit by altering ignition advances - 6/100 s after the threshold is exceeded;
Further torque reduction by reducing throttle opening (by the engine control unit with motorized throttle body) - after 15/100 s.
Effect on hydraulic system, braking action is exerted on the slipping wheel to give the differential a resistive force on the side with poor grip (T.C.)
This resistive force allows the differential to transmit an equal torque with good grip.
One wheel slipping on a bend with good grip (asphalt).
The system detects the presence of a bend from the rear wheel speed (drawn).
It implements the same intervention procedures described for when only one drive wheel is slipping; the cut-in thresholds are increased to the upper limit. The torque reduction is applied gradually.
One wheel slipping on a bend with poor grip (snow or ice).
It implements the same intervention procedures described for when only one drive wheel is slipping; the cut-in thresholds are increased to the lower limit. The torque reduction is accentuated (to ensure good car lateral containment).