Ride and Handling Optimization
Ride and Handling Optimization
COMPONENT LOCATION
INTRODUCTION
JaguarDrive control is a selectable vehicle optimization system designed to fine-tune the driving characteristics of the vehicle by accommodating different driving conditions or driving styles. The system allows the performance envelope of the vehicle to be stretched and prevents the necessity for a single, compromised configuration for all conditions. JaguarDrive control increases the vehicle's abilities by changing the characteristics of engine mapping, transmission shifts, stability and traction interventions, suspension settings and, on SC (supercharger) vehicles, the electronic differential settings.
JAGUARDRIVE CONTROLS
The system is controlled by buttons adjacent to the JaguarDrive selector on the floor console. The buttons allow the selection of one of the following three modes:
- Special modes off.
- Winter mode.
- Dynamic mode.
The instrument cluster will display the selected JaguarDrive control mode in the message center. For additional information, refer to Instrument Cluster
The JaguarDrive control system uses a combination of a number of vehicle sub-systems to achieve the required vehicle characteristics for the mode selected. The following sub-systems make up the JaguarDrive control system:
- EMS (engine management system). For additional information, refer to Electronic Engine Controls Electronic Engine Controls
For additional information, refer to Electronic Engine Controls Electronic Engine Controls
- Automatic transmission. For additional information, refer to Transmission Description Description and Operation
- Brake system. For additional information, refer to Anti-Lock Control - Stability Assist - 5.0L Description and Operation
- Adaptive dynamics. For additional information, refer to Vehicle Dynamic Suspension Description and Operation
- Electronic differential control (SC (supercharger) vehicles only). For additional information, refer to Rear Drive Axle and Differential - 5.0L
The JaguarDrive control software is stored in the JaguarDrive selector module located below the JaguarDrive selector. The module detects the selection made using the buttons and transmits a signal on the high speed CAN (controller area network) bus, which is received by each of the sub-system control modules.
Each of the affected sub-system control modules contain software, which applies the correct operating parameters to their controlled system for the JaguarDrive control mode selection made.
Each sub-system control module also provides feedback for the selected mode so that the JaguarDrive control software can check that all systems have changed to the correct operating parameters.
NOTE:
The JaguarDrive control system is a co-ordinating system only. It CANNOT generate a fault in one of the participating sub-systems. All participating sub-systems should be FULLY diagnosed before assuming a fault with JaguarDrive control. The JaguarDrive selector module should not be replaced until all other options have been exhausted.
Winter Mode
To activate winter mode, press the winter mode button briefly (not less than 500 ms) to activate or de-activate the mode.
NOTE:
Winter mode cannot be active at the same time as dynamic mode.
When active the winter mode icon and message appear in the instrument cluster message center to confirm the activation.
Dynamic Stability Control
Press the DSC (dynamic stability control) mode button briefly (not less than 300 ms) to switch between DSC and TracDSC. The instrument cluster message center will display either DSC ON or TRAC DSC depending on which selection is made. When TracDSC is selected, the DSC warning lamp in the instrument cluster is illuminated and the DSC button is illuminated. TracDSC is intended only for use on dry tarmac by suitably experienced drivers. For additional information, refer to Anti-Lock Control - Stability Assist - 5.0L Description and Operation
DSC can be manually switched off by pressing the DSC mode button for more than 10 seconds. Confirmation is given by a chime from the instrument cluster, DSC OFF is displayed in the instrument cluster message center and the DSC warning lamp in the instrument cluster is illuminated.
NOTE:
DSC is operational at all times when the engine is running unless manually switched off.
Dynamic Mode
To activate dynamic mode, press the button briefly. The dynamic mode button is illuminated. Dynamic mode confirmed message is displayed in the instrument cluster message center.
NOTE:
Dynamic mode cannot be active at the same time as winter mode.
In transmission sport mode and manual mode, the driver has full control over the transmission shift points and the TCM (transmission control module) will not intervene to prevent engine overspeed (i.e. automatic upshifts are inhibited). In this setting, the gear indicator in the instrument cluster will turn amber at high engine speeds to indicate an appropriate manual upshift point.
CONTROL DIAGRAM
NOTE:
A = Hardwired; D = High speed CAN (controller area network) bus
PRINCIPLES OF OPERATION
Engine Management System
The EMS varies the accelerator pedal maps to change the amount of torque per percentage of pedal travel. The EMS can also change the accelerator pedal response to control the allowed torque change relative to the speed of pedal travel.
Each driving mode uses a combination of operating parameters for each sub-system. Changing between driving modes initiates a different set of operating characteristics, which will be noticeable to the driver. The driver will notice differences in engine response when, for example, the accelerator pedal is held in a constant position and the driving mode is changed from winter to dynamic, the driver will notice the torque and engine speed increase. Similarly, if the mode is changed from normal or dynamic to winter, the driver will notice a reduction in torque and engine speed.
NOTE:
The change in torque and engine speed can take approximately 30 seconds and care must be taken not to confuse the JaguarDrive control system operation with an EMS fault.
Transmission Control
The TCM (transmission control module) changes the shift maps for the JaguarDrive control mode selected. This changes the shift points providing early or late upshifts and downshifts. For example, on slippery surfaces in winter mode the transmission will select 2nd gear for starting from a standstill on a flat surface to minimize wheel slip.
Anti-Lock Braking System Control
The ABS (anti-lock brake system) module controls several vehicle functions and adjusts the operating parameters of these functions to optimize the selected JaguarDrive control mode. Traction control uses different slip/acceleration thresholds to improve traction and vehicle composure. For example, the system sensitivity is increased on slippery surfaces to reduce wheel spin.
If TracDSC is selected or DSC is switched off, then subsequently the JaguarDrive control mode is changed, DSC is automatically switched back on.
The stability control uses different threshold values for the selected mode, reducing the requirement for the driver to change the DSC system mode for optimum performance in various driving scenarios.
Incorrect Mode Usage
Selection of an inappropriate mode is discouraged in the following ways:
- The active mode icon is continually displayed in the instrument cluster message center.
- In dynamic mode, when the ignition has been in the off position continuously for more than 6 hours, the JaguarDrive control system defaults to the special modes off (DSC on).
Selection of an inappropriate mode for the conditions will not endanger the driver or immediately cause damage to the vehicle. Continued use of an inappropriate mode may reduce the life of some components. The driver may notice a different vehicle response, with the engine and transmission responses being different than in the special modes off.
Driver Information
The message center contains the JaguarDrive control mode icons, which display the currently selected mode. If no symbol is displayed, no special mode is selected and the system is in special modes off.
In dynamic mode when the transmission is in sport and manual mode, the gear information is displayed in amber when the appropriate engine speed is reached for the optimum sporty change point.
Diagnostics
The JaguarDrive control system relies on the correct functionality of the sub-systems. If one of the sub-systems develops a fault, the JaguarDrive control system will not function, even though the fault is not in the JaguarDrive control system.
The JaguarDrive selector module and the mode buttons should only be investigated if there are no apparent faults in any of the sub-systems. If a fault in a sub-system is subsequently corrected, the JaguarDrive control system will function normally after an engine on and off cycle.
JaguarDrive Control Sub-System Faults
If a fault occurs in a sub-system, the driver is alerted by the illumination of a warning indicator and/or an appropriate message for that sub-system in the instrument cluster message center. No JaguarDrive control message will be shown when a failed sub-system displays its own message.
When a sub-system fault is present and the driver attempts to select a different JaguarDrive control mode or at the next ignition on cycle, a message WINTER MODE FAULT or DYNAMIC MODE FAULT will appear in the message center. This generally implies that the JaguarDrive control system has a fault, but only because a sub-system fault is preventing its operation. This message will be displayed once per ignition cycle, but is repeated if a further selection is made by the driver using the JaguarDrive control buttons or at the next ignition on cycle.
NOTE:
The message WINTER MODE FAULT or DYNAMIC MODE FAULT can also in very rare circumstances be generated by a fault in the JaguarDrive selector module.
NOTE:
It is not possible for the JaguarDrive selector module to cause any fault behavior (warning indicator illumination or message generation) in any of the sub-systems. Illumination of a sub-system warning indicator and/or a sub-system related message will never be associated with a JaguarDrive selector module or JaguarDrive control system fault.
The sub-system control modules can detect a fault with the CAN (controller area network) bus signal from the JaguarDrive selector module. If a fault in the JaguarDrive control system is detected, the sub-system control modules will operate in the special modes off setting. The sub-system control modules will record a fault code for a failure of the JaguarDrive control CAN (controller area network) signal. These faults can be retrieved using the Jaguar approved diagnostic tool and will provide useful information to indicate investigation of the JaguarDrive selector module or the CAN (controller area network) bus network.
JaguarDrive Control System or Selector Module Fault
If a fault occurs in the JaguarDrive control system, all button icon LED (light emitting diode) will be turned off (if applicable, background illumination will remain on) and pressing of the JaguarDrive control buttons is ignored. The instrument cluster message center will display a message WINTER MODE FAULT or DYNAMIC MODE FAULT when the fault occurs, if the fault is present and the driver attempts to select a special mode (if the control module is able to do this) or at the next ignition on cycle.
The JaguarDrive control buttons and selector module are an integrated unit. If a fault occurs in either component, the whole unit will require replacement, however, this is extremely unlikely.
CAN Bus Faults
If a CAN (controller area network) bus fault exists and prevents JaguarDrive control system operation, all of the JaguarDrive control button icon LED (light emitting diode) will be illuminated and pressing of the JaguarDrive control buttons is ignored.
If the instrument cluster does not receive a JaguarDrive control system CAN (controller area network) bus message from the JaguarDrive selector module, the message SPECIAL MODE UNAVAILABLE will be displayed when the fault occurs and will be repeated at every ignition on cycle.
User Error
A special mode change will not occur while DSC or ABS (anti-lock brake system) is active (including ABS (anti-lock brake system) cycling). This may be misinterpreted as a system fault.