PSM is an active control system for stabilization of the vehicle during extreme driving manoeuvres.
The increased control that is provided should not induce you to take greater risks with your safety. The limits dictated by the laws of physics cannot be overcome, even with PSM. The risk of accidents due to inappropriate speed cannot be reduced, even by PSM. The driver bears the responsibility for all driving maneuvers.
f Adapt your driving style to the prevailing road and weather conditions.
f Obey all traffic laws.
Advantages of PSM
- Superior traction and lane-holding ability in all driving situations - even on road surfaces with varying friction.
- PSM actively stabilizes the vehicle during dynamic driving maneuvers (e.g. rapid steering movements, during lane changes or on alternating curves).
- Improved braking stability in curves and on different or varying road surfaces.
Readiness for operation
PSM is switched on automatically every time you start the engine.
Sensors at the wheels, brakes, steering system and engine continuously measure:
- Steering angle
- Lateral acceleration
- Rate of turn about the vertical axis
- Brake pressure
PSM uses these values to determine the direction of travel desired by the driver. PSM intervenes and corrects the course if the actual direction of motion deviates from the desired course (steering-wheel position): It brakes individual wheels as needed. In addition, the engine power may be manipulated in order to stabilize the vehicle.
The events below inform the driver of PSM control operations and warn him to adapt his driving style to the road conditions:
- The multi-functional information light on the instrument panel lights up.
- Hydraulic noises can be heard.
- The vehicle decelerates and steering-wheel forces are altered as the PSM controls the brakes.
- Reduced engine power.
- The brake pedal pulsates and its position is changed during braking.
In order to achieve full vehicle deceleration, foot pressure must be increased after beginning the brake pedal pulsing.
Examples of PSM control operations
- If the front wheels of the vehicle drift on a bend, the rear wheel on the inside of the bend is braked and the engine power is reduced if necessary.
- If the rear of the vehicle swings out on a bend, the front wheel on the outside of the bend is braked.
The PSM should always be switched on during "normal" driving.
However, it may be advantageous to switch off
PSM temporarily in exceptional situations, for example:
-On a loose surface or in deep snow,
- When "rocking the vehicle free" and
Switching off PSM
f Press PSM OFF button.
PSM is switched off after a short delay. The light-emitting diode in the button is illuminated.
When the PSM is switched off, the multifunctional PSM light on the instrument panel is lit and a message is shown by the on-board computer.
An acoustic signal also sounds.
The following functions stabilize the vehicle in emergency situations, even with PSM switched off:
- When PSM is off, the vehicle is stabilized as soon as one of the two front wheels enters the ABS control range.
- When PSM is off and Sport mode is on, the vehicle is stabilized as soon as both front wheels enter the ABS control range.
One-sided spinning of the wheels is prevented, even with PSM switched off.
PSM is switched on after a short delay. The light-emitting diode in the button and the multifunctional PSM light go out. The on-board computer shows a message.
A sportier car set-up is obtained when Sport mode is switched on. PSM interventions are later than in Normal mode; the vehicle can be manoeuvred with greater agility at its performance limits, without the need to dispense with the assistance of PSM in emergency situations. This helps to achieve optimal lap times, particularly on race circuits and a dry road surface.
(25) Multifunctional PSM light
- The multifunctional light on the instrument panel lights up for a lamp check when the ignition is switched on.
- The light indicates a control operation by flashing, including when PSM is switched off (brake control in the event of one-sided wheel spin).
- In conjunction with a message on the on-board computer, the light indicates that PSM is switched off.
An acoustic signal also sounds.
- Faults are displayed by the light in conjunction with a message on the on-board computer. PSM is out of order.
f Please consult an authorized Porsche dealer.
f Please observe the chapter "PUTTING VEHICLE INTO OPERATION" on Page 239.
f Please observe the chapter "WARNINGS ON THE INSTRUMENT PANEL AND THE ONBOARD COMPUTER" on Page 105.
Towing f Please observe the chapter "VEHICLE TOWING" on Page 259.
Checks on test stands
When carrying out brake tests on roller test stands a maximum testing speed of 5 mph (8 km/h) must not be exceeded.
Handbrake checks on the roller brake tester must be performed only with the ignition switched off.
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