The cruise control system consists of the following main components:
| • | The CRUISE switch located on the multifunction lever. The switch includes the SET/ACCEL., RESUME/DECEL. and OFF buttons. |
| • | The Engine Control Module (ECM) located in the engine compartment. |
| • | The Accelerator Pedal Position (APP) sensor which is part of the accelerator pedal assembly. |
| • | The throttle motor is an integral part of the throttle position (TP) sensor. |
| • | The cruise control release switch is mounted on the brake pedal bracket. |
| • | The stoplamp switch is mounted on the brake pedal bracket. |
| • | The Electronic Brake Traction Control Module (EBTCM) provides the vehicle speed signal to the ECM. |
| • | The CRUISE indicator bulb in the instrument cluster. |
Cruise Switch Operation
SET/ACCEL
The SET/ACCEL switch activates the cruise control system which will only activate if the vehicle speed is at or above 40 km/h (25 mph). This switch also serves to accelerate the vehicle once the system is engaged. If the switch is held in the ACCEL position for more than one second, the system goes into the acceleration mode. The button is held until the desired speed is reached. When the switch is released, the system will maintain the desired speed. The SET/ACCEL switch can also be used to tap up the vehicle speed. Each tap on the switch will increase the vehicle speed in 1.6 km/h (1.0 mph) increments.
RESUME/DECEL
The RESUME/DECEL switch allows the cruise control system to return to the last speed setting recorded since the vehicle was last put in DRIVE, such as after momentarily braking. All cruise control information is erased when the vehicle is put in PARK. This switch will only work after an initial speed has been set using the SET/ACCEL switch. Do not hold the RESUME/DECEL switch in the RESUME position. This switch also decelerates the vehicle with the system operating. Holding the switch in the DECEL position lowers the vehicle speed. When the switch is released, the system will maintain the new cruise speed. The switch can also be used to tap down the vehicle speed in the same manner as the SET/ACCEL speed taps up the vehicle speed.
OFF
The OFF switch, when pressed, disengages the cruise control operation. The previous speed setting stored in memory is not retained after pressing the OFF switch.
Engine Control Module (ECM)
All cruise control functions are controlled and internal to the ECM. The ECM controls the throttle-valve angle with an electric throttle motor. The throttle motor is an integral part of the throttle position (TP) sensor.
When the ECM receives an input from the cruise control switch, the throttle-valve angle is modified by the throttle motor in order to reach or maintain a desired cruise speed.
Accelerator Pedal Position Sensor (APP) and Throttle Motor
The APP sensor monitors the position of the accelerator pedal and transmits this information to the ECM. The ECM processes the signal along with data transmitted from other systems (such as ABS and traction control) to calculate the control signal for the throttle motor. A closed-loop control circuit ensures precise adjustment of the throttle angle in a process based on signals transmitted to the ECM from a potentiometer within the TP sensor.
The ECM continuously monitors all components to ensure that the system is operating properly. Because the ECM and all sensors have backup units (redundancy), the system can compare the signal pairs to verify the monitoring process.
Cruise Control Release and Stoplamp Switches
Cruise Control Release Switch
The cruise control release switch is provided in order to disengage the cruise control. The switch is mounted on the brake pedal bracket assembly. The switch consists of one switch contact which is a normally closed switch when the brake is not applied. The switch contact opens when the brake pedal is applied. Pressing the brake pedal disengages the cruise control causing the throttle to return to the idle position.
Stoplamp Switch
The stoplamp switch is provided in order to disengage the cruise control. The switch is mounted on the brake pedal bracket assembly. The switch consists of two switch contacts which are normally open switches when the brake is not applied. The switch contacts close when the brake pedal is applied. One set of switch contacts are primarily for the cruise control disengage function. Pressing the brake pedal disengages the cruise control causing the throttle to return to the idle position.
Electronic Brake Traction Control Module (EBTCM)
The EBTCM is located in the LH side of the engine compartment and is mounted to the lower rail. The EBTCM receives a vehicle speed signal from the left rear vehicle speed sensor (VSS). The VSS produces an AC signal when the rear axle shaft rotates. The frequency of the signal is proportional at which speed the shaft rotates. The shaft speed is proportional to the speed of the vehicle.
The EBTCM processes the VSS signal and transmits the processed speed signal to the ECM.
CRUISE Indicator
The CRUISE indicator bulb in the instrument cluster illuminates when cruise control is engaged and operating.
