Principles Of Operation

The adaptive damping module uses a combination of information from other system modules and data from the accelerometers and suspension height sensors to measure the vehicle and suspension states and driver inputs. Using this information, the adaptive damping module applies algorithms to control the dampers for the current driving conditions.

The adaptive damping module receives signals on the high speed CAN bus from the following system components:

• Brake Pressure - ABS module.
• Brake Pressure Quality Factor - ABS module.
• Car Configuration Parameters - AJB.
• Center Differential Range Actual - ECM.
• Engine Speed - ECM.
• Engine Speed Quality Factor - ECM.
• Engine Torque Flywheel Actual - ECM.
• Engine Torque Flywheel Actual Quality Factor - ECM.
• Gear Position Target - TCM.
• Lateral Acceleration - ABS module.
• Power Mode (Ignition Signal) - CJB.
• Power Mode Quality Factor - CJB.
• Roll Stability Control Mode - ABS module.
• Steering Wheel Angle - ABS module.
• Steering Wheel Angle Speed - ABS module.
• Steering Wheel Angle Status - ABS module.
• Terrain Mode Requested - JaguarDrive selector.
• Torque Converter Slip - TCM.
• Vehicle Information Parameters HS - AJB
• Vehicle Speed - ABS module.
• Vehicle Speed Quality Factor - ABS module.
• Front Left Wheel Speed - ABS module.
• Front Left Wheel Speed Quality Factor - ABS module.
• Front Right Wheel Speed - ABS module.
• Front Right Wheel Speed Quality Factor - ABS module.
• Rear Left Wheel Speed - ABS module.
• Rear Left Wheel Speed Quality Factor - ABS module.
• Rear Right Wheel Speed Quality Factor - ABS module.
• Rear Right Wheel Speed - ABS module.

  The adaptive damping module also outputs information on the high speed CAN bus for use by other systems as follows:

• Fault Message - instrument cluster.
• Terrain Mode Change Status - JaguarDrive selector.
• Terrain Mode - JaguarDrive selector.

  The adaptive damping module monitors the input signals and operates the damper solenoids. The input signals are used in control modes and a force required for each damper for that mode is calculated. An arbitration mode monitors the force requirements from each mode and apportions a force to a damper. The force is converted to the appropriate current and sent to the damper.

  The control modes are as follows:

• Body Control - Uses CAN and accelerometer inputs. Calculates road induced body motions 100 times a second and sets each damper to the appropriate level to maintain a flat and level body.
• Roll Rate Control - Uses CAN inputs. Predicts vehicle roll rate due to driver steering inputs 100 times a second and increases damping to reduce roll rate.
• Pitch Rate Control - Uses CAN inputs. Predicts vehicle pitch rate due to driver throttle and braking inputs 100 times a second and increases damping to reduce pitch rate.
• Bump Rebound Control - Uses suspension height sensor and CAN inputs. Monitors the position of the wheel 500 times a second and increases the damping rate as the damper approaches the end of its travel.
• Wheel Hop Control - Uses suspension height sensor and CAN inputs. Monitors the position of the wheel 500 times a second and detects when the wheel is at its natural frequency and increases the damping to reduce vertical wheel motion.

Under normal road conditions when the vehicle is stationary with the engine running, the dampers are set to the firm condition to reduce power consumption.

The adaptive damping module receives its power supply via a relay and fuse in the CJB. The relay remains energized for a period of time after the ignition is off. This allows the adaptive damping module to record and store any DTC (diagnostic trouble code) relating to adaptive dynamics system faults.