Asr System - Ferrari 612 scaglietti Owner's Manual

ASR system

The ASR system controls the spinning of the driving wheels during
acceleration through the engine control unit (spark advance delay,
engine throttle opening reduction and fuel injection cut off) and the
rear brakes.
The ASR system adds stability to the vehicle and improves active safety
while driving, especially under the following conditions:
- internal wheel skidding on curves because of the dynamic variations
of the load or excessive acceleration;
- excessive power transmitted to the wheels, also in relation to road
conditions;
- acceleration on slippery, snowy or icy road surfaces;
- in the event of loss of grip on wet roads (aquaplaning).
The ASR system works together with the electronic suspension
adjusting system: under normal conditions ("SPORT" mode off),
stability in low and medium grip conditions has priority, while with
"SPORT" mode active, the system favours traction and optimises
vehicle performance.
ASR activation
The ASR system activates automatically every time the engine is started
and can be deactivated by pressing the button mentioned earlier on the
right-hand side of the steering wheel (see page 45).
Press the button once again to reactivate the system.
ASR malfunction indicators
The failure indicators are shared by the CST system.
MSR function (engine braking torque adjustment)
The ASR system also controls the engine braking torque when the
accelerator pedal is released under low grip conditions (e.g., snow, ice
etc.): in these conditions, the engine's high braking torque may cause
instability of the vehicle.
The system, using the same sensors as the ABS system, detects the
skidding of one or both of the driving wheels when the accelerator is
released and opens the motor-driven throttle for the engine supply
system. This reduces the braking torque and restores the maximum
grip conditions for the driving wheels.
However, the maximum deceleration that can be obtained with the engine
brake still depends on the tyre grip on the road. Snow or ice obviously reduce
grip values.
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