Cruise control is a speed control system that maintains a desired vehicle
speed under normal driving conditions at vehicle speeds above 40 km/h (25
mph). Steep grades may cause variations in the selected vehicle speeds.
The following are the main components of the cruise control system:
| • | The powertrain control module (PCM) |
| • | The Resume/Accel. Switch |
| • | The cruise control module |
| • | The clutch pedal position (CCP) switch, if equipped |
Cruise Control Engaged
The cruise control system will engage and adjust vehicle speed based
on the activation of the following cruise control switches:
The cruise control switches are located on the multifunction/turn signal
lever.
The cruise control module monitors the signal circuits of the cruise
control switches in order to determine when to capture and maintain the selected
vehicle speed. The cruise control module receives the VSS signal from the
PCM, via the VSS signal circuit. The cruise control module is an electronic
controller and an electric stepper motor. The electric controller monitors
the vehicle speed and operates the electric stepper motor. The electric stepper
motor moves a strap that is attached to the cruise control cable in order
to move the throttle linkage.
Ignition positive voltage is supplied from the 10 ampere CRUISE
fuse, to the cruise control switch and to the cruise control module. When
the cruise control On/Off switch is in the On position, the cruise control
module detects a high signal voltage on the cruise on switch signal circuit.
When the Set/Coast button is pressed, the cruise control module detects a
high signal voltage on the set/coast signal circuit. In order to engage the
cruise control system, the On/Off switch must be On and the Set button momentarily
pressed. The cruise control module sends a voltage signal to the PCM, via
the cruise control engaged signal circuit, in order to enable the cruise
control system. The PCM will confirm that the cruise control enable criteria
has been met. The cruise control module will record the selected vehicle
speed. Pressing the Resume switch will recall the previous selected vehicle
speed that is recorded in the cruise control module. Pressing the Accel.
switch will allow the vehicle to accelerate to a vehicle speed greater than
the current set vehicle speed. When the Accel. switch is released, the vehicle
speed will decrease to the current set vehicle speed. When the Resume/Accel.
switch is pressed, the cruise control module detects a high signal voltage
on the resume/accel switch signal circuit. Pressing the Coast switch will
allow the vehicle speed to decrease from the current set without deactivating
the cruise control system. When the Coast switch is released, the vehicle
will accelerate to the current set vehicle speed.
Cruise Control Disengaged
The cruise control module disengages the cruise control operation based
on the signals from the following switches:
The stop lamp switch is used to disengage the cruise control. The stop
lamp switch is mounted to the brake pedal bracket. Pressing the brake pedal
while the cruise control is engaged will disengaged the cruise control system.
When the brake pedal is pressed, the normally closed stop lamp switch opens
and the cruise control module detects a low signal voltage on the CCP switch
signal circuit. The vehicle speed stored in the memory of the
cruise control module will be erased when the Off button is pressed, or the
ignition switch is turned off.
Cruise Control Inhibited
The PCM inhibits the cruise control operation when any of the following
conditions exist:
| • | The vehicle is in PARK, REVERSE, NEUTRAL, or 1st gear. |
| • | The engine RPM is high, with fuel cut-off. |
| • | The vehicle speed is to high. |
| • | The battery is either overcharged or undercharged. |
| • | The antilock brake system/traction control system is active for
more than 2 seconds. |
The cruise control module assembly contains a low speed limit which
will prevent system engagement below a minimum speed of 40 km/h (25 mph).
