Jaguar XJ (X350). Manual — part 1197

412-02A : Heating and Ventilation

Specifications

Specifications

Torque Specifications

Description

Nm lb-ft lb-in

Heater hose bracket retaining bolt.

7

–

62

Heater core and evaporator core housing retaining nut.

7

–

62

Heater core and evaporator core housing retaining bolt.

7

–

62

Blower motor housing lower retaining nut.

7

–

62

Expansion valve manifold and tube assembly retaining bolt. 8

–

71

Auxillary coolant flow pump retaining bolt.

10 –

89

Engine compartment support retaining bolt.

25 18 –

Cabin filter housing retaining bolt.

6

–

53

Description and operation

Heating and Ventilation

The heating and defrosting system:

•

controls the vehicle air temperature, and during air conditioning (A/C) operation reduces the
relative humidity of the air inside the vehicle.

•

delivers heated or cooled air to maintain the vehicle interior temperature and comfort level.

•

controls the blower motor speed.

•

allows temperature to be adjusted individually by the driver and the passenger to maintain
comfort.

•

uses a reheat method to provide conditioned air to the passenger compartment. All airflow
from the blower motor passes through the A/C evaporator core. Temperature is regulated by
reheating a portion of the air and blending it with the remaining cool air to achieve the
desired temperature.

•

blends the air temperature by regulating the flow of air through or around the heater core.

The blower motor draws ambient air through the cabin air filter during all system operations except

for when the auto system switches to recirculation for maximum A/C performance, or when the

ambient air temperatue sensor requires the system to be in recirculation mode or when recirculation

is manually selected.

For additional information, refer to <<412-03>>.

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Item

Part Number

Description

1

—

Heater core

2

—

Heater core and evaporator core housing

3

—

Auxiliary coolant flow pump -3.5L and 4.2L only

4

—

Heater hose assembly

5

—

Blower motor

Heater core

The heater core consists of fins and tubes arranged to extract heat from the engine coolant and

transfer it to the air passing through the heater core and evaporator core. The heater core and

evaporator core is separated into two sections. Air passing through one section is directed to the

driver side of the vehicle, while air passing through the other section is directed to the passenger side

of the vehicle.

Auxiliary coolant flow pump vehicles fitted with 3.5L or 4.2L engine

The auxiliary coolant flow pump is electrically driven and provides increased coolant flow during low

engine speed operation. The pump is also used to circulate coolant after the engine is turned off

under certain conditions.

Blower motor

The blower motor pulls air from the air inlet and forces it into the heater core and evaporator core

assembly where it is mixed and distributed. The blower motor has eleven speeds (vehicles with

telematics have seven speeds) and is controlled by the climate control assembly.

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