Jaguar XJ (X350). Manual — part 1210

Description and operation

Air Conditioning

Item

Part Number

Description

1

—

Evaporator core

2

—

Air conditioning (A/C) compressor

3

—

Pressure cut off switch

4

—

Condenser core

The air conditioning (A/C) system components are:

•

A/C Compressor

•

Condenser core

•

Evaporator core

•

Thermostatic expansion valve

•

Desiccant bag

•

Connecting refrigerant lines

The refrigeration system operation is controlled by the:

•

thermostatic expansion valve.

•

evaporator discharge temperature sensor.

•

pressure cut off switch.

•

engine control module (ECM).

•

remote climate control module (RCCM).

The refrigerant system incorporates a variable capacity A/C compressor.

The RCCM monitors the evaporator discharge temperature sensor and communicates with the ECM

to control A/C compressor operation. The RCCM also monitors the ambient air temperature and

disables A/C operation when the ambient air temperature is below 0°C (30°F).

The pressure switch is located in the A/C compressor discharge line and communicates with the ECM.

If high or low refrigerant pressures are experienced, the ECM will interrupt A/C compressor

operation.

The pressure relief valve is installed in the A/C compressor and protects the system from excessively

high refrigerant pressure.

The thermostatic expansion valve, which is mounted to the evaporator core supply and return lines,

contains an adjustable orifice which provides the restriction that separates the high and low pressure

liquid phases in the refrigerant system.

A/C Compressor

NOTE:

The A/C compressor internal components are not serviced separately. The A/C compressor is

serviced only as an assembly.

The A/C compressor has the following characteristics:

•

A variable capacity function controlled by an external solenoid.

•

A displacement capacity of 160cc on the petrol variants and 170cc on the diesel variant.

•

The compressor is clutchless.

•

The compressor operates all the time (from 2% to 100% while the engine is running).

A/C Compressor Pressure Relief Valve

An A/C compressor pressure relief valve is incorporated in the compressor to:

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•

relieve unusually high refrigerant system discharge pressure buildups.

•

prevent damage to the A/C compressor and other system components.

•

avoid total refrigerant loss by closing after the excessive pressure has been relieved.

Condenser Core

The A/C condenser core has the following characteristics:

•

It is an aluminum fin and tube design heat exchanger located in front of the vehicle radiator.

•

It cools compressed refrigerant gas by allowing air to pass over fins and tubes to extract heat
and by condensing gas to liquid refrigerant as it is cooled.

•

The tube assembly mounted on the side of the condenser core contains the desiccant bag.

Desiccant Bag

The desiccant bag removes any retained moisture in the A/C system. The A/C system has an R-134a

leak trace dye wafer incorporated into the desiccant bag.

Refrigerant Lines

The manifold and tube assembly - thermostatic expansion valve carries high pressure liquid to the

thermostatic expansion valve and low pressure gas from the thermostatic expansion valve to the

manifold and tube assembly-compressor.

The tube assembly - A/C compressor to condenser carries the high pressure gas from the A/C

compressor to the condenser core. It also houses the high pressure service port and has a serviceable

high pressure relief valve.

The tube assembly - thermostatic expansion valve to the A/C compressor carries the low pressure gas

received from the thermostatic expansion valve to the compressor, houses the low pressure service

port and has a serviceable low pressure relief valve.

•

The manifold and tube assembly - A/C compressor vehicles fitted with 3.5 or 4.2L petrol
engines are are not interchangeable with vehicles fitted with a 3.0L petrol or 2.7L diesel
engines.

The tube assembly - condenser to thermostatic expansion valve carries high pressure liquid to the

manifold and tube assembly-thermostatic expansion valve and houses the high pressure service port.

Evaporator Core

The A/C evaporator core is the plate/fin type with a unique refrigerant flow path.

•

A mixture of refrigerant and oil exits the thermostatic expansion valve (TXV) and enters the
evaporator tank area through the 12.7 mm (0.5 in) tube.

•

The tank area is divided into three sections: front inlet, front outlet and rear tank.

•

The refrigerant enters the evaporator core tank area at the front inlet, flows down through
the core and up the back side in a "U-flow" pattern.

•

The refrigerant moves into the rear tank area and across to the other half of the core. The
refrigerant moves down through the core and back up the front side of the core to the front
outlet tank area.

•

The refrigerant at this point is in a gaseous state. It exits the evaporator through the 16 mm
(0.64 in) tube then passes through the TXV.

Item

Part Number

Description

1

—

Sensing bulb

2

—

Insulator

3

—

Hollow core pin-type retainer

4

—

Outlet port—low pressure liquid

5

—

Metering orifice

6

—

Inlet port—high pressure liquid

7

—

Spring

8

—

Evaporator inlet port—low pressure liquid

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