The Computer Command Ride (CCR) system controls the firmness
of the vehicle's ride by automatically controlling an actuator in each of
the four struts to increase ride firmness as speed increases. The three damping
modes are Comfort, Normal, and Sport. Damping mode selection is controlled
by the CCR Control Module according to vehicle speed conditions, vehicle
accelerator input, driver select switch position, and any error conditions
which may exist.
System Components
Control Module
The CCR Control Module is a computer used to control and monitor the
system. It is located on a bracket under the driver's seat. The Control Module
receives driver select switch, speed, and accelerator inputs and determines
the optimum mode strut valving for current operating conditions. The module
also receives feedback from the struts to determine proper system operation.
If the module receives an incorrect feedback signal, an error code will be
set in the Control Module and both driver select switch light emitting diodes
(L.E.D.s) will illuminate to display the error condition. For diagnostic
purposes, grounding the Diagnostic Enable circuit will cause both driver
select switch L.E.D.s to flash error codes.
Struts
Each strut contains an electrical actuator which rotates a selector
valve to a specific location commanded by the Control Module. The selector
valve contains different sized orifices which will increase or decrease the
damping rate of the strut to control ride firmness. Actuators are an integral
part of the strut and are not serviceable separately from the strut.
System Inputs and Outputs
Driver Select Switch Input
The driver select switch determines the operating mode of the system
as follows:
| • | In the TOURING RIDE switch position, the damping level depends
on vehicle speed and accelerometer inputs. |
| • | In the PERFORM RIDE switch position, the system will place the
damping level in the Firm mode regardless of vehicle speed and accelerometer
inputs. |
Speed Input
In the TOURING RIDE switch position, ride firmness is determined by
the following speed conditions:
| • | Speed increasing and below 6 mph (Stationary) - Sport mode. |
| • | Speed increasing and between 6 and 36 mph - Comfort mode. |
| • | Speed increasing and between 36 and 79 mph - Normal mode. |
| • | Speed increasing and above 79 mph - Sport mode. |
| • | Speed decreasing and above 76 mph - Sport mode. |
| • | Speed decreasing and between 76 and 32 mph - Normal mode. |
| • | Speed decreasing and between 32 and 2 mph - Comfort mode. |
| • | Speed decreasing and below 2 mph - Sport mode. |
Accelerator Input
The accelerometer input is used for lift, dive, and roll control with
the driver select switch in the NORMAL position. The Firm mode will be selected
if the accelerometer input is activated by lift, dive or roll conditions.
The system returns to its speed dependent mode 2 seconds after the accelerometer
input returns to the inactive state.
Driver Select Switch L.E.D. Feedback
Any system error will cause both driver select switch L.E.D.s to be
illuminated. The error display will exist as long as the error code is active.
If the fault corrects itself, the L.E.D.s will no longer display the error
condition, but the error code will be retained in the Control Module memory.
Error codes are stored in the Control Module in non-volatile (EEPROM) memory.
If the L.E.D.s are not displaying an error condition, one or the other
will be on to follow the driver select switch position, in Normal position
and the system is in the Firm mode due to accelerometer input, the Firm L.E.D.
will illuminate to show a shift to the Firm mode. The Normal L.E.D. then
will turn back on when the system returns to the Comfort mode.
If a code is set, a one second self diagnostic test is performed at
three minute intervals and whenever the driver select switch position is changed.
Both L.E.D.s will be on during this test and will go out if the fault is
corrected. If the fault still exists, the L.E.D.s will remain on.
