Cruise Control Description and Operation 4.3L, 5.0L, and 5.7L
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 vehicle speed sensor |
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. 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 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. 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 TCC/Brake switch and the stoplamp switch are incorporated into an
assembly and is used to disengage the cruise control. The stop lamp and TCC/Brake
switch are 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 TCC/Brake switch opens and
the normally open stoplamp switch closes. The cruise control module detects
a low signal voltage on the TCC/Brake signal circuit and detects a high signal
voltage on the stoplamp 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).
Cruise Control Description and Operation 8.1L
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 throttle actuator control (TAC) module |
Cruise Control Engaged
The PCM will engage and adjust vehicle speed based on the information
received from the TAC module via the serial data link. The TAC module monitors
the signal circuits of the following cruise control switches:
The cruise control switches are located on the multifunction/turn signal
lever.
Ignition positive voltage is supplied from the 10 ampere CRUISE
fuse, to the cruise control switch. When the cruise control On/Off switch
is in the On position, the TAC module detects a high signal voltage on the
cruise on switch signal circuit. When the Set/Coast button is pressed, the
TAC 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 in
the On position and the Set button momentarily pressed. The TAC module communicates
with the PCM, in order to confirm that the cruise control enable criteria
has been met. The PCM will also record the selected vehicle speed. When the
Resume/Accel. switch is pressed, the TAC module detects a high signal voltage
on the resume/accel switch signal circuit. Pressing the Resume switch will
recall the previous selected vehicle speed that is recorded in the PCM. 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. 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 PCM disengages the cruise control operation based on the information
received from the TAC module via the serial data link. The TAC module monitors
the signal circuits of the following switches:
The TCC/Brake switch is used to disengage the cruise control. The TCC/Brake
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 open TCC/Brake switch closes and
the TAC module detects a low signal voltage on the TCC/Brake signal circuit.
The vehicle speed stored in the memory of the PCM 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 speed is less than 40 km/h (25 mph). |
| • | 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. |
Cruise Control Description and Operation 6.5L
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 |
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 PCM monitors the signal circuits of the cruise control switches
in order to determine when to capture and maintain the selected vehicle speed.
Ignition positive voltage is supplied from the 10 ampere CRUISE
fuse, to the cruise control switch. When the cruise control On/Off switch
is in the On position, the PCM detects a high signal voltage on the cruise
on switch signal circuit. When the Set/Coast button is pressed, the PCM 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 PCM will confirm that the cruise control enable
criteria has been met. The PCM will also record the selected vehicle speed.
When the Resume/Accel. switch is pressed, the PCM detects a high signal voltage
on the resume/accel switch signal circuit. Pressing the Resume switch will
recall the previous selected vehicle speed that is recorded in the PCM. 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. 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 PCM disengages the cruise control operation based on the signals
from the following switches:
The TCC/Brake switch and the stoplamp switch are incorporated into an
assembly and is used to disengage the cruise control. The stop lamp and TCC/Brake
switch are 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 TCC/Brake switch opens and
the normally open stoplamp switch closes. The PCM detects a low signal voltage
on the TCC/Brake signal circuit and detects a high signal voltage on the stoplamp
signal circuit. The vehicle speed stored in the memory of the PCM 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 speed is less than 40 km/h (25 mph). |
| • | 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. |
