Suspension Control Module: Description and Operation

Porsche Dynamic Chassis Control (PDCC)

Control Unit







The control unit is installed under the rear seat at the right. The input data is evaluated continuously and appropriate control operations are initiated in the valve blocks over the vehicles entire speed range.

Analogue input signals:
- Level sensor, front left/right.
- Level sensor, rear left/right.
- Level sensor, rear right.
- Body acceleration sensor, front left/right.
- Body acceleration sensor, rear right.
- Rear-axle valve block: Pressure sensor 1, pressure sensor 2.
- Front-axle valve block: Pressure sensor 1, pressure sensor 2.
- PDCC button.

Input signals via drive CAN:
- Vehicle speed.
- Lateral acceleration.
- Yawing speed.
- Steering angle.
- Engine speed.
- Nominal engine idle speed.
- Outside temperature.

TECHNICAL MANUAL: Technical Data Increased risk of accidents and material damage if too much Pentosin CHF 202 is filled in or if Pentosin CHF 202 comes into contact with the coolant hoses when filling or topping off.

Output signals:
- Instrument cluster: Text, symbols.
- Rear-axle valve block: Direction valve, pressure regulating valve.
- Front-axle valve block: Direction valve, pressure regulating valve, failsafe valve.

Operation and Display Concept







Porsche Dynamic Chassis Control can be operated using the same chassis control switches Normal, Comfort and Sport that are used for PASM. PASM and PDCC are configured together, depending on which of the three chassis control programmes is selected.

In the Comfort setting, PDCC intervention occurs at reduced control speed so as not to change the character of the high comfort program. Active system intervention in the Sport program, on the other hand, occurs at maximum speed in order to optimize performance.







Enhanced off-road performance is also available automatically as soon as Low Range is activated.

Diagnostics

In addition to on-board diagnosis by the control units and checks on sensors and valves, the pressure that exists in the system is continuously monitored. Depending on the engine speed, the nominal pressure values that are worked out are compared with the current actual pressure values recorded by the four pressure sensors. If a fault is detected, PDCC switches to Fail-safe mode.

Error Message/Fail-Safe Mode










If a fault occurs during PDCC operation, the driver is alerted to this by the message "Chassis system defective" on the on-board computer.

The entire system is switched to fail-safe mode to ensure safe driving. The fail-safe valve in the front-axle valve block is de-energized, which causes the pump hydraulic system to short circuit. The hydraulic oil from the pump flows directly back into the reservoir. At the same time, the connections for the swivel motor are closed so that the pressure in the swivel motor is maintained. The anti-roll bar remains in this position and continues to work in the conventional way.

The hydraulic system on the rear axle is completely depressurized so that the vane controllers in the housing can turn freely and the anti-roll bar halves are decoupled. This increases the vehicle's lateral during cornering. The vehicle responds by understeering slightly, but can be driven at an appropriate speed to the nearest authorized Porsche dealer.