Daewoo Nubira. Manual — part 80

CRUISE CONRTOL SYSTEM 9U – 19

DAEWOO V–121 BL4

GENERAL DESCRIPTION

AND SYSTEM OPERATION

CRUISE CONTROL SYSTEM
OPERATION

The cruise control system automatically maintains a ve-
hicle speed set by the driver. When the cruise control sys-
tem is activated, speed is maintained or increased by
means of an electronically controlled cable attached to the
accelerator assembly. If the vehicle must be slowed to
maintain the speed set by the driver, the cruise control sys-
tem allows the throttle return spring to close the throttle.

If driving conditions require sudden acceleration after the
cruise control has been set, speed can be increased in the
normal manner by manually pressing the accelerator. The
cruise control is disengaged if the brakes (or the clutch,
with a manual transaxle) are applied.

The minimum speed for setting the cruise control is 38.6
km/h (24 mph). When cruise control is operating, the
CRUISE indicator lamp is turned ON in the instrument
cluster.

The cruise control system is capable of monitoring internal
software and hardware faults as well as external faults in
the connectors and the wire harness. If a fault is detected,
cruise control is stopped immediately, and the program
logic and hardware logic both prevent the cruise control
from opening the throttle.

The cruise control will function in temperatures ranging
from –40

°

C (–40

°

F) to 85

°

C (185

°

F). Maximum tempera-

ture could cause the regulation properties to be out of tol-
erance, but the safety shutdown is still operational under
maximum temperature conditions. If high temperature in-
terferes with the cruise control operation, the actuator
electromagnetic clutch will open, and the throttle return
spring will close the throttle unless the accelerator pedal
is pressed.

CRUISE CONTROL ACTUATOR

The cruise control actuator is a single–component sys-
tem. The electronic controls are combined in one housing
with the mechanical components. The actuator is
mounted in the passenger compartment..

The mechanical components of the cruise control actuator
are listed below:

S

Permanent field DC motor.

S

Single stage belt transfer gearing.

S

Spindle

drive.

S

Electromagnetic

clutch.

S

Clutch plate with cable attachment.

S

End

switches.

S

Plastic housing with noise reduction cover.

S

Damping unit for clutch plate slap.

The electronics of the cruise control system include the
following items:

S

A microprocessor which controls speed regulation
and monitors input signals.

S

A clutch activation circuit which energizes the
clutch magnet in order to couple the DC motor to
the control cable.

S

A driver circuit which activates the DC motor in a
clockwise or counterclockwise direction.

S

A control unit for lamp activation.

The parts of the cruise control actuator are not service-
able. The entire actuator must be replaced if there is an
electronic or mechanical defect in one of the systems.

MAIN SWITCH

The cruise control main switch is on the center of the in-
strument panel.

Cruise control can only be set with the lever switch when
the main switch is ON.

The main switch has an indicator which turns ON when the
main switch is pressed. If the switch is pressed again, the
indicator and the switch turn OFF.

The main switch also is connected to the instrument illumi-
nation system, so the dimmer switch controls switch illumi-
nation when the headlamps or parking lamps are ON.

LEVER SWITCH

After the main switch is turned ON and the neutral position
of the lever switch is detected by the cruise control actua-
tor, the following operations can be performed by using the
cruise control lever switch:

Set – If the cruise control is ON and the minimum speed
is 38.6 km/h (24 mph) but not more than 155 km/h (96
mph), the target speed can be set by selecting the SET
function for 10 to 300 milliseconds. If SET is selected for
more than 300 milliseconds, the cruise will be activated in
the COAST function. If the accelerator is pressed by the
driver after the cruise control has been set, the previous
target speed will be maintained when the accelerator is re-
leased. If the accelerator is pressed by the driver until the
actual speed is more than 35 km/h (22 mph) over the tar-
get speed, or until the vehicle exceeds 160 km/h (99 mph),
the cruise control will disengage.

Coast – If a target speed has been set and COAST is se-
lected for at least 300 milliseconds, the throttle is allowed
to return to idle and the vehicle will coast. When the
COAST switch is released, the current speed will be main-
tained as the new target speed. If the vehicle speed drops

9U – 20

I

CRUISE CONRTOL SYSTEM

DAEWOO V–121 BL4

below 32.2 km/h (20 mph) while coasting, the cruise con-
trol will be disengaged. If the switch is released between
32.2 km/h (20 mph) and 38.6 km/h (24 mph), the minimum
target speed of 38.6 km/h (24 mph) will be used.

Resume – If the cruise control is ON and the system is dis-
engaged by using the brake or the clutch, exceeding the
maximum speed, failing to maintain the minimum speed,
or exceeding the target speed by more than 35 km/h (22
mph), the last memorized speed can be reset by selecting
RESUME, if the time since disengagement is not greater
than 5 seconds. The RESUME function is selected by
switching to RESUME for 10 to 300 milliseconds. If the ac-
tual speed is below the target speed when RESUME is se-
lected, the vehicle will be accelerated at 3.4 km/h per sec-
ond (2.1 mph/second) until the vehicle is within 10 km/h (6
mph) of the target speed, and then acceleration will be re-
duced in order to achieve a smooth transition from accel-
eration to cruising. If the actual speed is above the target
speed when RESUME is selected, the throttle will be al-
lowed to return to idle until the target speed is achieved.
RESUME can be canceled by selecting SET. In that case,
the current speed will be maintained as the new target
speed.

Accelerate – If cruise control is ON, and the ACCEL func-
tion is selected for more than 300 milliseconds, the vehicle
will accelerate. The acceleration is maintained at the rate
of 3.4 km/h per second (2.1 mph/second) as long as ve-
hicle performance is sufficient; otherwise full throttle is ap-
plied. When the switch is released, the current speed will
be stored and used as the new target speed. The ACCEL
function cannot be used for acceleration above 155 km/h

(96 mph). If 155 km/h (96 mph) is attained, acceleration
will stop and 155 km/h (96 mph) will be set as the new tar-
get speed.

Tap–Up – If the cruise control has been set, and RESUME
is selected again for more than 10 milliseconds but less
than 300 milliseconds, the target speed will be increased
by 2 km/h (1.2 mph) each time the RESUME function is
selected (or tapped). If the driver has used the accelerator
to increase speed more than 8 km/h over the current target
speed, a tap–up signal will be interpreted as a normal SET
signal. The cruise control will not accept a tap–up target
speed above 155 km/h (96 mph). If the actual speed has
fallen 16.1 km/h (10 mph) below the target speed, tap–up
signals are not accepted.

Tap–Down – If the cruise control is already set and SET
is selected for between 10 and 300 milliseconds, the target
speed will be decreased by 2 km/h (1.2 mph) each time
SET is selected (or tapped). Tap–down signals will not be
accepted for a target speed below 38.6 km/h (24 mph). If
the vehicle speed has increased to 8 km/h (5 mph) over
the target speed, the cruise control system will interpret a
tap–down signal as a SET.

If the cruise control is turned OFF with the main switch, all
cruise control functions are stopped, the actuator cable is
driven toward idle, and the electromagnetic clutch for the
cable actuator is opened. The cable actuator clutch is not
opened immediately in order to accomplish a smooth tran-
sition in vehicle speed. If the cruise control is OFF for more
than 5 seconds, the memorized target speed is erased.

SECTION : 9C

HORNS

CAUTION : Disconnect the negative battery cable before removing or installing any electrical unit or when a tool
or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cable will help
prevent personal injury and damage to the vehicle. The ignition must also be in LOCK unless otherwise noted.

TABLE OF CONTENTS

SPECIFICATIONS

9C–1

. . . . . . . . . . . . . . . . . . . . . . . . . .

FASTENER TIGHTENING SPECIFICATIONS

9C–1

.

SCHEMATIC AND ROUTING DIAGRAMS

9C–2

. . . . .

HORN WIRING SYSTEM

9C–2

. . . . . . . . . . . . . . . . . . .

MAINTENANCE AND REPAIR

9C–3

. . . . . . . . . . . . . . .

ON–VEHICLE SERVICE

9C–3

. . . . . . . . . . . . . . . . . . . . .

HORNS

9C–3

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GENERAL DESCRIPTION AND SYSTEM

OPERATION

9C–5

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

HORNS

9C–5

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SPECIFICATIONS

FASTENER TIGHTENING SPECIFICATIONS

Application

N

S

m

Lb–Ft

Lb–In

Horn Bolt

20

15

–

9C – 2

I

HORNS

DAEWOO V–121 BL4

SCHEMATIC AND ROUTING DIAGRAMS

HORN WIRING SYSTEM