Content .. 1209 1210 1211 1212 ..
Jaguar XJ (X350). Manual - part 1211
9
—
Pin
10
—
Evaporator outlet port—low pressure gas
11
—
Housing
The thermostatic expansion valve has the following characteristics:
•
It is mounted on the evaporator core supply and return lines.
•
It is a block-type valve.
•
It contains an internal sensing bulb to increase the effectiveness of temperature sensing.
•
It is not serviceable. A new thermostatic expansion valve must be installed as a unit.
Pressure Cut Off Switch
The pressure cut off switch monitors the A/C compressor discharge pressure and communicates with
the engine control module (ECM). The ECM will interrupt A/C compressor operation in the event that
the pressure cut off switch indicates high system discharge pressures. It is also used to sense no or
low charge conditions. If the pressure is below a predetermined value for a given ambient
temperature, the ECM will interrupt A/C compressor operation.
•
The pressure cut off switch is mounted on a Schrader-type valve fitting on the compressor to
condenser discharge line.
•
A valve depressor, located inside the threaded end of the pressure cut off switch, presses on
the Schrader valve stem and allows the pressure cut off switch to monitor the compressor
discharge pressure.
•
When the compressor discharge pressure rises to approximately 2,896 kPa (420 psi), the
ECM will interrupt the compressor operation and disable the compressor.
•
When the pressure drops to approximately 1,724 kPa (250 psi) the ECM will enable the A/C
compressor circuit.
Service Gauge Port Valves
WARNING: Wear eye protection when opening/servicing the service gauge port valves.
The high-pressure service gauge port valve is located on the tube assembly - condenser to
thermostatic expansion valve.
The low pressure service gauge port valve is located on the manifold and tube assembly - A/C
compressor.