Cruise Control Description and Operation 3.6L
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 engine control module (ECM) |
| • | The Resume/Accel switch |
| • | The torque converter clutch (TCC) brake/cruise release switch |
| • | The throttle actuator control (TAC) motor |
| • | The vehicle speed sensor |
Cruise Control Engaged
The cruise control system will engage and adjust the 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 engine control module (ECM) monitors the signal circuits of the cruise control
switches in order to determine when to capture and maintain the selected vehicle
speed. The ECM uses the throttle actuator control (TAC) motor in order to control
the vehicle speed. For further information on the TAC system, refer to
Throttle Actuator Control (TAC) System Description
in
Engine Controls - 3.6L (LY7).
Ignition positive voltage is supplied from the 10-ampere CRUISE fuse
to the cruise control switch via the ignition 1 voltage circuit. When the normally
open cruise control on/off switch is turned ON, the switch closes and the ECM detects
a high signal voltage on the cruise control on switch signal circuit. When the normally
open set/coast switch is pressed, the switch closes and the ECM detects a high signal
voltage on the cruise control set/coast switch signal circuit. To engage the cruise
control system, turn the On/Off switch On and momentarily press the set/coast switch.
The ECM will confirm that the cruise control enable criteria has been achieved. The
ECM will engage the cruise control system and record the selected vehicle speed. The
ECM sends a class 2 message to the instrument panel cluster in order to illuminate
the cruise control indicator. Pressing the accelerator pedal, 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 current set vehicle speed 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 is momentarily pressed,
with a minimum vehicle speed of 37 km/h (23 mph). When the normally
open resume/accel switch is activated, the switch closes and the ECM detects a high
signal voltage on the cruise control resume/accel switch signal circuit. Activating
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 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 activating 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 activated, with the maximum acceleration total
of 16 km/h (10 mph) over the current set vehicle speed . Momentarily
activating the resume/accel switch, after the cruise control system has been disengaged
by pressing the brake pedal, will recall the previous set vehicle speed that is recorded
in the ECM.
Cruise Control Disengaged
The engine control module (ECM) disengages the cruise control operation based
on the signals from the following switches:
| • | The torque converter clutch (TCC) brake switch |
The TCC brake switch and the stop lamp switch are incorporated into an assembly
and are mounted to the brake pedal bracket. Pressing the brake pedal while the cruise
control is engaged will disengaged the cruise control system. The ECM monitors the
TCC brake switch/cruise control release signal circuit and the stoplamp switch signal
circuit. When the brake pedal is pressed, the normally closed TCC brake switch opens
and the normally open stoplamp switch closes. The ECM detects a low signal voltage
on the TCC brake switch/cruise control release signal circuit and detects a high signal
voltage on the stop lamp switch signal circuit. The cruise control system will also
disengage when the cruise control On/Off switch is turned Off. The vehicle speed stored
in the memory of the ECM will be erased when the cruise control On/Off switch is turned
to Off, or the ignition switch is turned off.
The cruise control system will disengage when the ECM detects that the driver
has the accelerator pedal override active for approximately 60 seconds.
When the cruise control system is disengaged, the ECM sends a class 2
message to the instrument panel cluster (IPC) in order to deactivate the cruise control
indicator.
Cruise Control Inhibited
The engine control module (ECM) inhibits the cruise control operation when any
of the following conditions exist:
| • | A cruise control system related DTC has been set. |
| • | 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 too low. |
| • | The engine RPM is too high. |
| • | The vehicle speed is too high. |
| • | The system voltage is not between 6 volts and 16 volts. |
| • | The antilock brake system/traction control system is active for more than
2 seconds. |
Cruise Control Description and Operation 3.5L
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 |
| • | The torque converter clutch (TCC) brake/cruise release switch |
| • | The throttle actuator control (TAC) module |
| • | The vehicle speed sensor |
Cruise Control Engaged
The cruise control system will engage and adjust the 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 powertrain control module (PCM) monitors the signal circuits of the cruise control switches in order to determine when to capture and maintain the selected vehicle speed. The PCM uses the throttle actuator control (TAC) module and the TAC
motor in order to control the vehicle speed. For further information on the TAC system, refer to
Throttle Actuator Control (TAC) System Description
.
Ignition positive voltage is supplied from the 10-ampere CRUISE fuse to the cruise control switch via the ignition 1 voltage circuit. When the normally open cruise control on/off switch is turned ON, the switch closes and the PCM detects a high
signal voltage on the cruise control on switch signal circuit. Similarly, when the normally open resume/accel switch or set/coast switch is pressed, the switch closes and the PCM detects a high signal voltage on either the cruise control resume/accel switch
or set/coast switch signal circuit. To engage the cruise control system, turn the On/Off switch ON and momentarily press the set/coast switch. The PCM will confirm that the cruise control enable criteria has been achieved. The PCM will engage the cruise control
system and record the selected vehicle speed. The PCM sends a class 2 message to the instrument panel cluster in order to illuminate the cruise control indicator. Pressing the accelerator pedal, 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
current set vehicle speed 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 PCM 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 is momentarily pressed, with a minimum vehicle speed of 37 km/h (23 mph). Activating 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 cruise control system is engaged, momentarily activating 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 activated, with the maximum acceleration total of 16 km/h (10 mph) over the current set vehicle speed . Momentarily activating the resume/accel switch, after the
cruise control system has been disengaged by pressing the brake pedal, will recall the previous set vehicle speed that is recorded in the PCM.
Cruise Control Disengaged
The powertrain control module (PCM) disengages the cruise control operation based on the signals from the following switches:
| • | The torque converter clutch (TCC) brake switch |
The TCC brake switch and the stop lamp switch are incorporated into an assembly and are mounted to the brake pedal bracket. Pressing the brake pedal while the cruise control is engaged will disengaged the cruise control system. The PCM monitors the TCC
brake switch/cruise control release signal circuit and the stoplamp switch signal circuit. 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 switch/cruise control release signal circuit and detects a high signal voltage on the stop lamp switch signal circuit. The cruise control system will also disengage when the cruise control On/Off switch is turned OFF. The vehicle speed stored in the memory
of the PCM will be erased when the cruise control On/Off switch is turned to OFF, or the ignition switch is turned OFF.
The cruise control system will disengage when the PCM detects that the driver has the accelerator pedal override active for approximately 60 seconds.
When the cruise control system is disengaged, the PCM sends a class 2 message to the instrument panel cluster (IPC) in order to deactivate the cruise control indicator.
Cruise Control Inhibited
The powertrain control module (PCM) inhibits the cruise control operation when any of the following conditions exist:
| • | A cruise control system related DTC has been set. |
| • | 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 too low. |
| • | The engine RPM is too high. |
| • | The vehicle speed is too high. |
| • | The system voltage is not between 9 volts and 16 volts. |
| • | The antilock brake system/traction control system is active for more than 2 seconds. |
