Opel Frontera UE. Manual - part 1245

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

1A–101

EndOFCallout

The actuator changes the motor speed using the gear
and drives each door rotating the output axis united with
the sliding contact.

860RW026

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The mode and mix actuators are common actuators
with the built-in potentiometer.  For the intake actuator,
the contact switch type is selected.
The potentiometer is a register assembled to the printed
circuit board of the mix and mode actuators.  It detects
the air mix door position specified by rotation of the
output axis as a ratio of the variable terminal (VM)
voltage against the reference voltage (VDD: 5V), then
signals the value to the automatic air conditioner control
unit.

C01RX016

Movement of Mix Actuator

Position of the air mix door is determined by the
controller on the automatic heater/air conditioner control
unit.
As the heat or cool side of the controller is grounded,
the transistor on the driver is activated and, thus, the
motor rotation is turned on.  The sliding contact
connected to the motor sends the position detection
signal from the potentiometer to the automatic air
conditioner control unit.  As the set temperature and
interior temperature are balanced, the controller returns
to the neutral and the motor rotation is stopped.

C01RX005

Legend

(1) Mix Actuator
(2) Heater Unit
(3) Intake Actuator
(4) Mode Actuator
(5) Blower Unit

Legend

(1) Output Axis
(2) Motor
(3) Printed Circuit Board
(4) Sliding Contact

C-45

Rotation 

direction

Remarks

(+) side

(-) side

8

6

Clockwise

Full heat side

6

8

Counter 

clockwise

Full cool side

SECTION

1A–102

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

Movement of Mode Actuator

As target position of the mode door is decided on the
controller of the control unit, the control unit reads the
position detection signal from the actuator to select the
clockwise or counter clockwise motor rotation direction.
Grounding the controller VENT or DEF side after the
direction selection activates the transistor on the driver,
thus turning on the motor rotation.  Accompanying the
motor rotation, the sliding contact rotates, too.  When
the target position is reached, the controller on the
control unit returns to the neutral and the motor stops.

C01RX017

Movement of Intake Actuator

The controller on the automatic air conditioner control
unit selects an intake mode to be used.
 As the Terminal No.5 C65 is grounded via the sliding
contact on the terminal plate, the transistor on the driver
is activated, thus turning on the motor rotation.  Then,
accompanying move of the motor, the sliding contact
rotates until grounding of the Terminal No.5 C65 is

removed, thus stopping the motor.

C01RX006

Overview of Automatic Control of
Automatic Air Conditioner

The automatic heater and air conditioner on this vehicle
has the following features:

• Interior temperature control.

• Air flow control.

• Mode (blow port) control.

• Intake (switching between fresh air and interior air)

control.

• Heater start timing control.

• Cooler start timing control.

• Compressor ON/OFF function according to outside

air temperature level.

• Evaporator anti-freeze control.

Interior Temperature Control

The automatic air conditioner control unit operates on
the setup temperature signal from the temperature
control switch and other sensor signals to derive the
total signal.  Then, the control unit compares this signal
against the signal from the potentiometer to determine
rotation direction of the mix actuator.  The mix actuator
moves the air mix door to the aperture specified by the
total signal so that the specified interior temperature is
achieved.
If the compressor is turned off in the A/C (air
conditioning) mode, aperture of the air mix door is offset

Conduction pin

Rotation 

direction

Remarks

(+) side

(-) side

5

1

Clockwise

VENT to DEF 

direction

1

5

Counter 

clockwise

DEF to VENT 

direction

Grounding 

terminal

Rotation 

direction

Remarks

No.5 C-65

Clockwise

RE-CIRCULATI

ON

→

MIX

→

FRE

SH

SECTION

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

1A–103

according to the outside air temperature or the specified
interior temperature.  This function removes the
difference in the blowing temperature in this state and
that of when the compressor is turned on.
When FH or FC is selected for the setup temperature,
the air mix door is accordingly fixed to the Full Heat or
Full Cool mode.
When the VENT mode is selected, aperture of the air
mix door is controlled so that excessively heated air may
not be blown from the VENT blow port.

C01RY00015

Air Flow Control

In the Auto Mode

• The automatic air conditioner control unit operates on

the setup temperature signal and other sensor
signals to derive the total signal.  Then, the control
unit adjusts base potential of the power transistor to
match it to the voltage pattern of the target fan so that
stage-less fan speed control can be achieved.
When solar radiation quantity is detected in the VENT
or B/L mode, the control unit increases the minimum
fan voltage to offset.
When FH or FC is selected from the temperature
control switch, air flow is accordingly fixed to MAX HI
or AUTO HI.

In the Manual Mode

• Air flow specified from the fan switch is entered to the

automatic air conditioner control unit as the manual
signal.  The signal modifies the air flow to the level
specified from the fan switch so that the required fan
voltage is attained.

C01RY00008

Mode (Blow Port) Control

The automatic air conditioner control unit operates on
the setup temperature from the control switch, and
temperature and solar radiation quantify from the
sensors to determine the total mode control signal.
According to the pattern specified by this signal, the
control unit selects either one of the VENT, BI-LEVEL,
FOOT or DEF/FOOT mode.
The mode actuator determines the rotation direction
comparing the target position against the current
position being determined by the position detection
signal.
When FH or FC is selected for the temperature from the
temperature control switch, mode is accordingly fixed to
the VENT or FOOT.

• In the manual operation of the mode switch, you can

select a desired blow port mode pressing the
corresponding mode switch.

SECTION

1A–104

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

• Operating the DEF mode switch selects the DEF for

the blow port mode.

C01RY00009

Intake (Fresh air/interior air switching)
Control

In the Full Auto mode, the automatic heater/air
conditioner control unit operates on the setup
temperature signal and other sensor input signals to
derive the total signal.  According to the pattern
specified by this signal, the control unit provides the
intake control.
When the fan is turned off or the A/C (air conditioning) is
turned off, the intake is fixed to the FRESH mode.
When FC or FH is selected from the control switch, the
intake mode is accordingly fixed to the RECIRC or
FRESH.
In the Manual Operation

• Pressing the FRESH (fresh air intake) or the RECIRC

(room air circulation) accordingly selects the FRESH
or RECIRC mode.

When the DEF Mode Switch is depressed

• The intake mode is fixed to the FRESH.  When the

MANU REC is selected, however, the mode is fixed
the RECIRC.

When the Mode Switch is depressed

• If the automatic intake control is selected, the intake

is fixed to the currently selected mode.

C01RY00012

Compressor Control

In the automatic control mode, the automatic air
conditioner control unit turns on or off the compressor
with the evaporator anti-freeze mechanism using the
evaporation sensor.  And, when outside air is detected
to be low through the outside air temperature sensor
signal, the control unit turns off the compressor using
the compressor control function.
Manual Control

• In the automatic control mode, pressing the A/C (air

conditioning) switch turns off the compressor.

SECTION