Caution: Do not use the cruise control on slippery roads, steeply graded roads,
or in heavy traffic of heavy or varying volume. Failure to follow these CAUTIONS
could possibly cause you to loose control of the vehicle and result in damage
to the vehicle and personal injury.
Cruise control is a speed control system that maintains a desired vehicle speed
under normal driving conditions. The cruise control allows the driver to maintain
a constant speed of 40 km/h (25 mph) or higher without depressing
the accelerator. Any steep grades up or down may cause variations in the selected
speeds. The cruise control system performs the following functions:
The cruise control system consists mainly of the following components:
• | The cruise control servo assembly (6) |
• | The cruise control release and clutch pedal position (CPP) switch, manual
transmission only |
• | The cruise control mode switch - RESUME/
ACCEL, COAST/ SET, and CANCEL (1) |
• | The main cruise control switch - CRUISE
ON/OFF |
• | The powertrain control module (PCM) |
• | The transmission range switch, automatic transmission only |
• | The vehicle speed sensor (VSS) |
The cruise control servo assembly allows the system to control and maintain
the desired vehicle speed. The functions of the cruise control system are received
and acted upon by the cruise control module. The cruise control module is incorporated
into the cruise control servo assembly. The cruise control module sends a command
through the cruise control servo to engage the system when the module receives
one of the following signals from the cruise control mode switch:
When a command is received by the servo, the direct current (DC) servo turns
a worm gear. The turning of the worm gear moves the accelerator cable in order
to adjust the throttle angle. The DC servo and the worm gear connect mechanically
only when a magnetic clutch, situated between the DC servo and the worm gear, energizes.
The system is disengaged when the cruise control module sends a command to
the cruise control servo. The cruise control module receives a cancel signal from
any of the following components:
• | The main cruise control switch - CRUISE
ON/OFF |
• | The cruise control mode switch - RESUME/
ACCEL, COAST/ SET, and CANCEL (1) |
• | The transmission range switch, automatic transmission only |
• | The clutch pedal position (CPP) switch, manual transmission only |
Upon receiving a cancel signal, the cruise control servo assembly de-energizes
the magnetic clutch. When the magnetic clutch de-energizes, the DC servo motor
and the worm gear mechanically disconnect. The throttle returns to the idle position.
Cruise Control Servo Assembly
The cruise control servo assembly is mounted to the left inner wheelhouse panel
in the engine compartment. The cruise control servo assembly consists of the following
components:
• | The cruise control module |
The cruise control servo actuates the accelerator cable in order to increase
and decrease the throttle angle in response to signals from the following locations:
• | The main cruise control switch - CRUISE
ON/OFF |
• | The cruise control mode switch - RESUME/
ACCEL, COAST/ SET, and CANCEL (1) |
• | The vehicle speed sensor (VSS) - speedometer |
The input signals received by the cruise control servo assembly are broken
down into the following categories:
• | The speed control input |
The main cruise control switch - CRUISE ON/O5FF provides the ON/OFF signal
to the cruise control servo assembly in order to activate and deactivate the cruise
control system.
The cruise control mode switch (1) provides the following speed control
input signals:
• | The RESUME/ACCEL - resume/accelerate |
The cruise control servo assembly uses the speed control input signals and
the vehicle speed signal from the VSS in order to determine, maintain, or alter
the vehicle speed. The vehicle speed depends on the driver commands.
The powertrain control module (PCM) provides the throttle position signals
to the cruise control servo assembly through of the throttle position (TP) sensor.
The throttle position signals allow the cruise control servo assembly to constantly
monitor the throttle position during the operation of the cruise control system.
The cancel input signals are provided to the cruise control assembly by the
following components:
• | The cruise control switch CANCEL button (2) |
• | The transmission range switch - automatic transmission only |
• | The clutch pedal position (CPP) switch - manual transmission only |
The cancel input signals inform the cruise control servo assembly to immediately
suspend the cruise control operation.
An output signal is sent to the open side of the DC servo motor when the cruise
control servo assembly senses a drop in the vehicle speed below the desired cruise
speed. The output signal causes the DC servo motor to perform the following actions:
• | Increase the vehicle speed to the desired cruise speed |
An output signal is sent to the closed side of the DC servo motor when the
cruise control actuator assembly senses that the vehicle speed is above the desired
cruise speed. The output signal causes the DC servo motor to perform the following
actions:
• | Turn the opposite direction |
• | Decrease the vehicle speed to the desired cruise speed |
The cruise control servo assembly de-energizes the magnetic clutch when a cancel
input signal is received. The cancel signal disengages the DC servo motor from
the worm gear. Disengaging the DC servo motor causes the throttle to go to the
idle position. The cruise control operation cancels when the throttle is in the
idle position.
Vehicle Speed Sensor (VSS)
The vehicle speed sensor (VSS) is mounted on either the transfer case or transmission.
The VSS converts the vehicle speed into a pulse signal. The pulse signal sends
the input to the cruise control servo assembly.
Cruise Control Release and Clutch Pedal Position (CPP) Switch - Manual
Transmission
The cruise control release and clutch pedal position (CPP) switch mounts under
the instrument panel, directly above the clutch pedal. The CPP switch closes, providing
a ground to the cruise control servo assembly, whenever you press the clutch
pedal. The cruise control servo assembly disengages the cruise control system
operation as soon as the ground signal is sensed.
Transmission Range Switch - Automatic Transmission
The transmission range switch mounts to the transmission. The transmission
range switch closes, providing a ground to the cruise control servo assembly,
when the manual lever is in the PARK or the NEUTRAL position. The cruise
control servo assembly disengages the cruise control system operation as
soon as the ground signal is sensed.
Stop Lamp Switch
The stop lamp switch is under the instrument panel, directly above the brake
pedal. When you press the brake pedal, 1 set of the stop lamp switch contacts
close. The closed contacts provide a voltage signal to the cruise control servo
assembly. The cruise control servo assembly disengages the cruise control operation
as soon as the voltage signal is sensed.
When you press the brake pedal, another set of stop lamp switch contacts open.
The open contacts interrupts the voltage circuit from the cruise control servo
assembly to the magnetic clutch, inside the assembly. With the voltage removed
from the magnetic clutch, the actuator DC servo disengages from the worm gear.
This action permits the throttle to return to the idle position. This ensures
the cancellation of the cruise control operation during vehicle braking.
Throttle Position (TP) Sensor
The throttle position (TP) sensor supplies a throttle position voltage signal
input to the powertrain control module (PCM). The PCM converts the TP sensor
signal into a throttle duty signal. The duty signal is relative to the rate
at which the throttle plate is opening. The cruise control actuator assembly
uses the information in order to determine the throttle opening angle.
Cruise Indicator
The cruise indicator is in the upper center portion of the instrument cluster (1).
The cruise indicator lights in order to inform the driver that the cruise control
system is operational.
Main Cruise Control Switch (CRUISE ON/OFF)
The main cruise control switch - CRUISE ON/OFF has 2 momentary
contact buttons. The main cruise control switch is on the instrument panel, to
the right of the steering column. The switch turns the cruise control system ON
or OFF. Once the main cruise switch is turned ON, it will be operational whenever
the ignition switch is turned on.
RESUME/ACCEL Switch
The RESUME/ ACCEL - Resume/ Accelerate switch (1) is a part of
the cruise control mode switch. The RESUME/ ACCEL switch returns the cruise control
system operation to the last speed setting after a cancel input signal is received
by the cruise control servo assembly, such as vehicle braking.
The RESUME/ ACCEL switch activates when the cruise control switch momentarily
rotates clockwise. Do not hold the cruise control switch in the RESUME/ACCEL
position. If you hold the cruise control switch in the RESUME/ACCEL position
for more the 1 second, the system will go into the accelerate mode.
Rotate and hold the cruise control switch in the RESUME/ ACCEL position in
order to accelerate during the cruise control system operation. When the
cruise control switch releases, the cruise control system will maintain the
new cruise speed.
In order to use the accelerate mode, the following conditions must be present:
• | You must press the main cruise control switch - CRUISE ON/OFF. |
• | The CRUISE indicator must be lit. |
• | The vehicle speed must be over 25 mph (40 km/h). |
COAST/ SET Switch
The COAST/SET switch is part of the cruise control mode switch (1).
The COAST/SET switch activates when the cruise control switch rotates counterclockwise
into the COAST/SET position.
When you rotate the cruise control switch to the COAST/SET position and release
the switch the vehicle will travel at the previously set speed. The following
conditions must be present in order for the COAST/SET switch to operate:
• | You must press the main cruise control switch - CRUISE ON/OFF. |
• | The CRUISE ON/OFF indicator must be lit. |
• | The vehicle speed must be over 40 km/h (25 mph). |
The COAST/ SET switch may be used in order to decease the cruise speed. Rotate
the cruise control switch counterclockwise to the COAST/ SET position. Hold
the cruise control switch in order to disengage the cruise control system and
return the throttle to the idle position. When the new, lower cruise speed
is reached, the cruise control switch will release from the COAST/ SET position.
The cruise control system will re-engage and maintain the new cruise speed.
You may press the accelerator at any time in order to override the cruise control
system operation. Release the accelerator in order to return the vehicle
to the previously set cruise speed.
CANCEL BUTTON
The CANCEL button (2) is part of the cruise control mode switch (1).
When you press the CANCEL button, the button signals the cruise control
servo assembly in order to immediately suspended cruise control operation.
When the ignition is turned to the ON position, battery voltage is applied
to cavity 12 of the cruise control servo through the closed contacts of
the main relay. Ground for the cruise control servo is applied at cavity 11.
Depressing and releasing the main cruise control switch closes the momentary switch
contacts and signals the cruise control servo at cavity 8 to turn ON. The
cruise control servo then grounds cavity 10 to turn ON the cruise control
switch indicator lamp. The vehicle speed sensor (VSS) signal is applied at cavity 1
of the cruise control servo and allows it to monitor vehicle speed.
Operating the cruise control mode switch applies the following resistances
between cavities 5 and 8 of the cruise control servo:
Whenever the cruise control system is in operation, ground from cavity 4
of the cruise control servo is applied to the CRUISE indicator in the Instrument
Cluster.
When the brake pedal is depressed, one set of the stop lamp switch contacts
close and applies B+ voltage to the brake lights and to cavity 2 of the
cruise control servo which cancels the cruise control operation. The other set
of stop lamp switch contacts open and removes B+ voltage from cavity 6 of
the cruise control servo which removes voltage to the magnetic clutch in the cruise
control servo.
Cruise control operation is also canceled when ground is applied at cavity 9
of the cruise control servo during the following conditions:
• | Clutch pedal depressed - Manual Transaxle. |
• | Manual selector placed in the P or N position - Automatic Transaxle. |
The Powertrain Control Module (PCM) provides a throttle position sensor signal
to cavity 7 of the cruise control servo. This signal is used by the cruise
control servo as one of the factors in determining when to provide an overdrive
cutoff signal to the PCM.
When certain driving conditions exist which require the vehicle to shift out
of overdrive, the cruise control servo sends an overdrive cutoff signal from cavity 3
to the PCM.