Frelander 2. Manual - part 413

The pollution sensor allows the ATC module to monitor intake air for the level of carbon monoxide (CO) and oxides of nitrogen
(NOx). The sensor is mounted on the RH side of the heater casing.

• NOTE: The pollution sensor is an optional fit on vehicles with a dual zone, automatic climate control system.

The pollution sensor is provided an ignition controlled feed from the Battery Junction Box (BJB) and provides one of the
following 4 signals to the ATC module based on ambient air quality:

Static or reduced pollution levels
Small increase in pollution levels
Medium increase in pollution levels
Rapid or large increase in pollution levels.

Based on the signal from the pollution sensor, the ATC module is able to control the intake air source to reduce the amount of
contaminants entering the cabin. This function is fully automatic, but can be overridden by manual selection of the air intake
source using the fresh/recirculated air switch on the control panel.

CONTROL DIAGRAM

• NOTE: A = Hardwired; D = High Speed CAN bus; N = Medium Speed CAN bus; O = LIN bus

Item

Part Number

Description

Battery

Blower motor

LH temperature blend stepper motor

Windshield distribution (defrost) stepper motor

Pollution sensor

Cabin humidity sensor

Air intake stepper motor

RH temperature blend stepper motor

Face/feet distribution stepper motor

Ambient air temperature sensor

A/C compressor solenoid - i6 only

ECT sensor

Refrigerant pressure sensor

Cabin temperature sensor

Evaporator temperature sensor

ECM

ATC module

Fuse 27, CJB

Blower motor control module

Sunload sensor

Fusible link 17, BJB

PRINCIPLES OF OPERATION

Intake Air Control - Single Zone Manual System

The intake air source is controlled manually by pressing the fresh/recirculated air switch located on the control panel. W hen
pressed, the ATC module will illuminate the switch tell-tale Light Emitting Diode (LED) and close the air intake door. A second
press of the switch will cause the ATC module to extinguish the switch LED and open the air intake door, allowing fresh air to
enter the cabin.

• NOTE: The ATC module will reduce the amount of fresh air entering the cabin to reduce the ram effect caused by forward
motion of the vehicle.

W hen recirculated air is selected, the ATC module will return the air intake door to the open position after a period of 3
minutes. This helps prevent misting within the cabin. The 3 minute time period for recirculated air can be overridden by
pressing and holding the fresh/recirculated air switch until the switch LED flashes 3 times. The air intake door will now remain
closed until the next drive cycle.

The ATC module controls the position of the air intake door by providing LIN bus messages to the air intake door stepper
motor. A Hall effect sensor located within the stepper motor informs the ATC module that movement of the stepper motor is
taking place.

Intake Air Control - Dual Zone Automatic System

The intake air source is controlled automatically unless overridden by pressing the fresh/recirculated air switch located on the
control panel. Under automatic control, the ATC module determines the required position of the air intake door using its
'comfort' algorithm based on inputs from the ambient air temperature sensor and the cabin temperature sensor.

W hen the vehicle first enters power mode 6 (ignition on), the tell-tale LED on the fresh/recirculated air switch will be
illuminated and the air intake source will be automatically controlled by the ATC module. The ATC module will control the
intake air source according to ambient air temperature and requested cabin temperature. The intake air door will be opened to
allow fresh air into the cabin, although a small amount of recirculated air will also be present.

• NOTE: The ATC module will reduce the amount of fresh air entering the cabin to reduce the ram effect caused by forward
motion of the vehicle.

A single press of the fresh/recirculated air switch will extinguish the tell-tale LED. The ATC module will now close the air
intake door and provide only recirculated air into the cabin for a period of 3 minutes. After this period, the ATC module will
return the air intake door to automatic control. This helps prevent misting within the cabin.

A second press of the fresh/recirculated air switch will also return the intake air source to automatic control and illuminate the
tell-tale LED.

The 3 minute time period for recirculated air can be overridden by pressing and holding the fresh/recirculated air switch until
the switch LED flashes 3 times. The air intake door will now remain closed until the next drive cycle.

Intake Air Control - Dual Zone Automatic System with Pollution Sensor

• NOTE: The ATC module will reduce the amount of fresh air entering the cabin to reduce the ram effect caused by forward
motion of the vehicle.

W hen the vehicle first enters power mode 6 (ignition on), the 'AUTO' tell-tale LED on the fresh/recirculated air switch will be
illuminated and the air intake source will be automatically controlled by the ATC module. A single press of the
fresh/recirculated air switch will extinguish the 'AUTO' tell-tale LED and illuminate the 'MAN' tell-tale LED. The ATC module
will now close the air intake door and provide only recirculated air into the cabin for a period of 3 minutes. After this period,
the ATC module will return the air intake door to automatic control. This helps prevent misting within the cabin.

A second press of the fresh/recirculated air switch will extinguish both the 'AUTO' and 'MAN' tell-tale LED's. The ATC module
will now control the intake air source according to ambient air temperature and requested cabin temperature. The air intake
door will be opened to allow fresh air into the cabin, but a small amount of recirculated air will also be present. The amount
of recirculated air is determined by the ATC module using its 'comfort' algorithm based on inputs from the ambient air
temperature sensor and the cabin temperature sensor.

A third press of the fresh/recirculated air switch returns the air intake source to automatic control and will illuminate the
'AUTO' tell-tale LED.

The 3 minute time period for recirculated air can be overridden by pressing and holding the fresh/recirculated air switch until
the switch LED's flash 3 times. The air intake door will now remain closed until the next drive cycle.

The ATC module controls the position of the air intake door by providing LIN bus messages to the air intake door stepper

motor. A Hall effect sensor located within the stepper motor informs the ATC module that movement of the stepper motor is
taking place.

Air Temperature Control - Single Zone Manual System

Cabin temperature selection is made by turning the LH rotary controller to the required position. Turning the controller counter
clockwise will lower the temperature of the air exiting the heater assembly; turning the controller clockwise will raise the
temperature of the air exiting the heater assembly.

Maximum heating and cooling is represented on the control panel by a red and blue dot respectively. W hen either maximum
heating or cooling is selected, the 'comfort' algorithm in the ATC module will adopt a suitable strategy for air source, air
distribution and blower speed to maintain maximum heating or cooling within the cabin.

The ATC module adjusts the temperature of the air exiting the heater assembly by moving the position of the temperature
blend door. The temperature blend door directs a proportion of cooled air from the evaporator through the heater core to
produce the required temperature output. The ATC module adjusts the position of the temperature blend door by providing
LIN bus messages to the blend door stepper motor. A Hall effect sensor located within the stepper motor informs the ATC
module that movement of the stepper motor is taking place.

Air Temperature Control - Dual Zone Automatic System

Dual zone systems feature 2 rotary heating controllers, which allow individual climate control for the LH and RH sides of the
cabin. Temperature selection can be made by turning the controller to the required temperature marked on the control panel.
Turning either controller past the 16°C (61°F) mark will initiate the maximum cooling strategy; turning either controller past
the 28°C (82°F) mark will initiate the maximum heating strategy.

• NOTE: Maximum cooling or heating can only be achieved if both rotary controllers are set to the same position.

The ATC module is able to maintain constant temperatures in both sides of the cabin by monitoring the feedback from the
cabin temperature sensor. Unless any manual overrides have been selected, the ATC module will automatically control the
intake air source, air distribution into the cabin and blower speed to maintain the required temperatures.

Dual zone systems feature 2 temperature blend doors, allowing individual temperature output for the LH and RH sides of the
cabin.

• NOTE: The drivers side temperature setting has priority over the passengers side temperature setting.

The temperature blend doors are mounted on the LH side of the heater assembly and direct a proportion of cooled air from
the evaporator through the heater core to provide the required temperature outputs. The ATC module controls the position of
the temperature blend doors by providing LIN bus messages to the blend door stepper motors. Hall effect sensors located
within the stepper motors inform the ATC module that movement of the stepper motors is taking place.

Blower Motor Control - Single Zone Manual System

Blower motor speed is set by turning the RH rotary controller to the required position. The RH rotary controller allows the
selection of 14 blower motor speeds. Turning the controller fully counter clockwise will turn the blower motor off.

Operation of the blower motor is controlled by the ATC module via the blower motor control module. The ATC module provides
a PW M signal to the blower motor control module based on the selected blower speed. The blower motor control module
interprets the PW M signal as a blower motor speed and controls the voltage to the blower motor accordingly.

Blower Motor Control - Dual Zone Automatic System

Blower motor speed is controlled automatically by the ATC module unless a manual override has been requested. Manual
overrides to blower motor speed can be made by turning the central rotary controller to the required position. The rotary
controller allows the manual selection of 7 blower motor speeds. Turning the controller fully counter clockwise will turn the
blower motor off. When a manual override has been made, the 'AUTO' LED located in the center of the rotary controller will
extinguish.

• NOTE: The central rotary controller contains 2 LED's. The top (round) LED will illuminate when the blower motor is under
automatic control. The bottom (rectangular) LED will illuminated when air distribution into the cabin is under automatic
control (see below).

The blower motor can be returned to automatic control by pressing the 'AUTO' switch located in the center of the rotary
controller. Under automatic control, the ATC module varies the speed of the blower motor in line with its 'comfort' algorithm
to maintain the required cabin temperature. The ATC module will also vary the blower motor speed to compensate for the ram
effect on intake air produced by forward movement of the vehicle.

Operation of the blower motor is controlled by the ATC module via the blower motor control module. The ATC module provides
a PW M signal to the blower motor control module based on the required blower speed. The blower motor control module
interprets the PW M signal as a blower motor speed and controls the voltage to the blower motor accordingly.

Air Distribution Control - Single Zone Manual System

Air distribution into the cabin can be adjusted by turning the central rotary controller to the required position. The ATC module
adjusts the position of the air distribution door to the required position by providing LIN bus messages to the air distribution
door stepper motor. A Hall effect sensor located within the stepper motor informs the ATC module that movement of the
stepper motor is taking place.

Air Distribution Control - Dual Zone Automatic System

Air distribution into the cabin is controlled automatically by the ATC module unless any manual overrides have been
requested. Manual overrides can be made by pressing the appropriate air distribution momentary switch on the control panel.
If a manual override has been requested, the 'AUTO' LED located in the center of the blower motor rotary controller will
extinguish.

• NOTE: The central rotary controller contains 2 LED's. The top (round) LED will illuminate when the blower motor is under
automatic control (see above). The bottom (rectangular) LED will illuminated when air distribution into the cabin is under

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