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 clutch start switch, if equipped with a manual transmission |
• | The engine control module (ECM) |
• | The Resume/Accel Switch |
• | The cruise/brake Switch |
• | The throttle actuator control (TAC) motor |
• | The vehicle speed sensor |
Cruise Control Engaged
The cruise control system will engage and adjust vehicle speeds based on the
activation of the following cruise control switches:
The cruise control switches are located on the steering wheel.
The ECM monitors the signal circuits of the cruise control switches. The ECM
uses the status of the cruise control switches in order to determine when to capture
and maintain the selected vehicle speed. The ECM monitors the signal circuit of the
vehicle speed sensor in order to determine the desired vehicle speed. The ECM uses
the TAC motor in order to maintain the vehicle speed. For further information on the
TAC system, refer to (WAITING FOR LINK) in Engine Controls--2.2 L (L61)
or to
Throttle Actuator Control (TAC) System Description
in Engine Controls--3.0 L
(L81).
Ignition positive voltage is supplied to the cruise control switches from the
2 ampere CRUISE fuse, located in the IPC fuse block. When the normally open
cruise control On/Off switch is switched On , the switch closes and the ECM detects
a high signal voltage on the cruise on switch signal circuit. The cruise control indicator,
located on the cruise control On/Off switch, will illuminate when the cruise control
On/Off switched is switched On. To engage the cruise control system, turn the cruise
control system ON by pressing the cruise control On/Off switch On and momentarily
press the Set/Coast switch. When the Set/Coast switch is pressed, the normally open
set/coast switch closes and the ECM detects a high signal voltage on the set/coast
switch signal circuit. The ECM will confirm that the cruise control enable criteria
has been met and then engage the cruise control system. The ECM will record the selected
vehicle speed. Pressing the accelerator, while the cruise control system is engaged,
will allow the driver to override the cruise control system in order to accelerate
the vehicle beyond the current set vehicle speed. When the accelerator pedal is released,
the vehicle will decelerate and resume the current set vehicle speed. The driver can
also override the cruise control system via the Set/Coast switch and the Resume/Accel
Switch. When the cruise control system is engaged, pressing and holding the Set/Coast
switch will allow the vehicle to decelerate from the current set vehicle speed without
deactivating the cruise control system. When the Set/Coast switch is released, the
ECM will record the vehicle speed and maintain the vehicle speed as the new set vehicle
speed. When the cruise control system is engaged, momentarily pressing the Set/Coast
switch will allow the vehicle to decelerate at 1.6 km/h (1 mph) increments
for each time that the Set/Coast switch is momentarily pressed, with a minimum vehicle
speed of 37 km/h (23 mph). Pressing and holding the Resume/Accel switch,
when the cruise control system is engaged, will allow the vehicle to accelerate to
a greater vehicle speed than the current set vehicle speed. When the Resume/Accel
switch is pressed, the normally open resume/accel switch closes and the ECM detects
a high signal voltage on the resume/accel switch signal circuit. When the Resume/Accel
switch is released, the ECM will record the vehicle speed and maintain the vehicle
speed as the new set vehicle speed. When the cruise control system is engaged, momentarily
pressing the Resume/Accel switch will allow the vehicle to accelerate at 1.6 km/h
(1 mph) increments for each time that the Resume/Accel switch is momentarily
pressed, with a maximum acceleration total of 16 km/h (10 mph) over
the current set vehicle speed. Momentarily pressing the Resume/Accel switch, when
the cruise control system has been disengaged by pressing the brake pedal, will recall
the previous selected vehicle speed that is recorded in the ECM.
Cruise Control Disengaged
The ECM disengages the cruise control operation based on the signals from the
following switches:
• | The clutch start switch |
• | The cruise/brake switch |
The cruise/brake switch, the clutch start switch, and the stoplamp switch are
used to disengage the cruise control system. The stop lamp and cruise/brake switch
are incorporated into an assembly and are mounted to the brake pedal bracket. When
the brake pedal is pressed, the normally closed cruise/brake switch opens and the
normally open stoplamp switch closes. The ECM detects a low signal voltage on the
cruise/brake signal circuit and detects a high signal voltage on the stoplamp switch
signal circuit. When the clutch pedal is pressed, the normally closed clutch start
switch opens and the ECM detects a low signal voltage on the clutch start switch signal
circuit. The cruise control system will disengage when the cruise control On/Off switch
is switched to Off. The vehicle speed stored in the memory of the ECM will be erased
when the cruise control On/Off switch is turned Off, or the ignition switch is turned
off.
The cruise control system will disengage when the ECM detects that a driver
override function has been active for approximately 60 seconds.
Cruise Control Inhibited
The ECM inhibits the cruise control operation when any of the following conditions
exist:
• | A cruise control related DTC has been set. |
• | The antilock brake system/traction control system is active for more
than 2 seconds. |
• | The engine RPM is too low. |
• | The engine RPM is too high. |
• | The system voltage is not between 9 volts and 16 volts. |
• | The vehicle speed is less than 40 km/h (25 mph). |
• | The vehicle speed is too high. |
• | The vehicle is in PARK, REVERSE, NEUTRAL, or 1st gear. |