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Frelander 2. Manual - part 436

Item

Part Number

Description

Automatic Temperature Control (ATC) module

Fuel Fired Booster Heater (FFBH)

Auxiliary coolant pump

Ambient air temperature sensor

Auxiliary fuel pump

FFBH Receiver

FFBH antenna matching unit

OVERVIEW

The Fuel fired Booster Heater (FFBH) is rated at 5 kW and compensates for the relatively low coolant temperatures
inherent in the diesel engine. The unit is located behind the Right Hand (RH) front fender splash shield and heats engine
coolant downstream of the heater core.

Operation of the FFBH is controlled by the Automatic Temperature Control (ATC) module via the medium speed Controller
Area Network (CAN) bus. Operation of the FFBH is influenced by:

Ambient air temperature
Engine coolant temperature.

The FFBH will operate if the ambient air temperature is lower than 5 °C (41 °F) and stop if ambient temperature reaches 8
°C (46 °F). Operation of the FFBH may also be inhibited if the fuel level drops below a predetermined level.

Remote Operation - Vehicles from 2009MY

On vehicles from 2009MY the FFBH has remote operation. The remote system includes the addition of a FFBH receiver,

FFBH antenna matching unit and a remote handset for operation of the system. The FFBH unit remains as previously fitted
but has upgraded software. The Engine Control Module (ECM) also has a software calibration upgrade. The instrument
cluster message center displays FFBH messages when required.

AUTOMATIC TEMPERATURE CONTROL MODULE

The ATC module is mounted in the center console and is integral with the control panel. The module works in conjunction
with the ECM to control all aspects of heating, ventilation, and Air Conditioning (A/C).
For additional information, refer to:

Control Components

(412-01 Climate Control, Description and Operation).

AUXILIARY FUEL PUMP

Item

Part Number

Description

Fuel line connector

Non return valve

Solenoid coil

Plunger

Filter insert

Fuel line connector

O-ring seal

Spring

Piston

Bush

The auxiliary fuel pump is mounted on the RH side of the fuel tank and regulates the fuel supply to the FFBH. The pump is
a self priming, solenoid operated plunger pump, controlled by a Pulse W idth Modulation (PW M) signal from the control
module in the FFBH. W hen the pump is de-energized, it provides a positive shut-off of the fuel supply.

The solenoid coil of the auxiliary fuel pump is installed around a housing which contains a plunger and piston. The piston
locates in a bush, and a spring is installed on the piston between the bush and the plunger. A filter insert and a fuel line
connector are installed in the inlet end of the housing. A non return valve and a fuel line connector are installed in the fuel
outlet end of the housing.

While the solenoid coil is de-energized, the spring holds the piston and plunger in the closed position at the inlet end of
the housing. An O-ring seal on the plunger provides a fuel tight seal between the plunger and the filter insert, preventing
any flow through the pump. W hen the solenoid coil is energized, the piston and plunger move towards the outlet end of
the housing, until the plunger contacts the bush; fuel is then drawn in through the inlet connection and filter. The initial
movement of the piston also closes transverse drillings in the bush and isolates the pumping chamber at the outlet end of
the housing. Subsequent movement of the piston then forces fuel from the pumping chamber through the non return valve
and into the line to the fuel fired booster heater. W hen the solenoid de-energizes, the spring moves the piston and
plunger back towards the closed position. As the piston and plunger move towards the closed position, fuel flows past the
plunger and through the annular gaps and transverse holes in the bush to replenish the pumping chamber.

FUEL FIRED BOOSTER HEATER (FFBH)

The FFBH is installed in the coolant supply line to the heater assembly and is located behind the RH front fender splash
shield. Two electrical connectors connect the FFBH to the vehicle wiring.

The FFBH comprises the following:

A combustion air fan
A burner housing
A heat exchanger
An air inlet hose and muffler
An exhaust pipe and muffler
A control module.

Sectioned View of Typical Fuel Fired Booster Heater

Item

Part Number

Description

Combustion air fan

Coolant outlet

Coolant inlet

Burner insert

Heat exchanger

Temperature sensor

Exhaust

Fuel inlet

Evaporator

Air inlet

Combustion Air Fan

The combustion air fan regulates the flow of air into the FFBH to support combustion of the fuel supplied by the auxiliary
fuel pump. It is also used to purge and cool the FFBH.

Burner Housing

The burner housing contains the burner insert and also incorporates connections for the exhaust pipe, the coolant inlet
from the auxiliary coolant pump and the coolant outlet to the vehicle heater.

The burner insert incorporates the fuel combustion chamber, an evaporator and a glow pin and flame sensor. Fuel from the
auxiliary fuel pump is supplied to a venturi, where it evaporates and enters the combustion chamber to mix with air from
the combustion air fan. The glow pin and flame sensor provides the ignition source for the fuel:air mixture and, once
combustion is established, monitors the flame.

Heat Exchanger

The heat exchanger transfers heat generated by combustion to the coolant. Two sensors are installed in the heat
exchanger casing to provide the control module with inputs of Engine Coolant Temperature (ECT). The control module uses
the temperature inputs to control system operation.

Air Inlet Hose and Muffler

A canister type muffler is included in the air inlet supply line. The muffler reduces the noise caused by induction roar.

Exhaust Pipe and Muffler

The exhaust pipe and muffler directs exhaust combustion gases to atmosphere below the front RH wheel arch. Exhaust
vapor may be visible when the FFBH is running, depending on atmospheric conditions.

Control Module

The control module controls and monitors operation of the FFBH system. An internal flow of air from the combustion air fan
ventilates the control module to prevent it overheating.

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