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Porsche Stability Management (PSM)

PSM is an active control system for stabilizing the vehicle in extreme driving situations. It is automatically enabled when the engine starts.

PSM makes use of the automatic brake differential (ABD) and the anti-slip regulation (ASR) as well as the functions of the anti-lock braking system (ABS) and the engine drag torque control (EDC).

Loss of control of the vehicle
Despite the advantages of PSM, it is still the driver's responsibility to adapt his driving style and driving maneuvers to the prevailing road and weather conditions, as well as the traffic situation.

The increased safety provided should not induce you to take greater risks with your safety. The limits set by the laws of driving physics cannot be overcome, even with PSM.

PSM does not reduce the risk of accidents owing to an inappropriate driving speed.

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The events below inform the driver of the PSM control operations:

1. PSM warning light on the instrument panel flashes.
2. Hydraulic noises are audible.
3. Vehicle decelerations and modification of steering wheel forces through targeted brake intervention.
4. Reduced engine power.
5. Pulsing brake pedal and changes in brake pedal position when braking.
   To achieve full vehicle deceleration, the foot pressure must be increased after the brake pedal starts to pulse.

Automatic brake differential (ABD)
If one wheel on a driven axle starts to spin, it is braked so that the other wheel on the same axle can be driven.

Anti-slip regulation (ASR)
Anti-slip regulation prevents wheels from spinning through targeted adjustment of engine power, thereby ensuring good road-holding ability and stable vehicle handling.

Engine drag torque control (EDC)
In conditions of excessive slip, the engine drag torque control system prevents all driven wheels from locking up when the vehicle is overrunning. This is also the case when shifting to a lower gear on a slippery road.

Steering torque pulse
Steering torque pulse provides the driver steering assistance when braking on roads with varying friction values.

Additional steering forces also assist the driver during countersteering.

Activating PSM Sport

1. Vehicles with Sport Chrono package.

In sport PSM mode, the system operates in a particularly sporty mode.

Restricted PSM support
In PSM Sport mode, the support provided by PSM is restricted in critical driving situations outside the ABS control range.

• Always have PSM Sport switched off during "normal" driving operation.
• Never activate PSM Sport when driving with a collapsible spare wheel.

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• Press button briefly.
  The button's light indicator and the PSM OFF warning light on the instrument panel light up.
  A warning appears on the multifunction display indicating that PSM Sport is activated.

Switching off PSM

Fig. 173: PSM OFF button in the center console

Absent PSM support
When PSM is switched off, PSM support is no longer provided in critical driving situations outside of the ABS control range.

• Always have PSM switched on during "normal" driving operation.
• Never switch off PSM when driving with a collapsible spare wheel.
  

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