Purpose
The expansion valve atomizes liquid refrigerant to facilitate cooling of the evaporator.
Function
The expansion valve reduces the pressure of liquid refrigerant rapidly to facilitate vaporization of the atomized refrigerant at the evaporator, and adjusts the refrigerant amount sent into the evaporator.
Construction
The expansion valve consists of the following parts:
Diaphragm
Temperature sensor
Shaft
Expansion valve body
Ball valve
Spring

Operation
Adjustment of the refrigerant amount supplied to the evaporator is performed by the ball valve opening angle in the expansion valve.
The opening angle adjustment is performed according to the balance of the following forces:

Refrigerant pressure (Pd) in diaphragm
Refrigerant gas pressure (PI) of evaporator under diaphragm
Spring force (Fs) pushing up ball valve
If the refrigerant gas temperature from the evaporator increases, the expansion valve increases the amount of refrigerant according to the following operations:

The temperature of the temperature sensor tightly sealed against the diaphragm increases.
The refrigerant in the diaphragm warms and the Pd increases.
If this Pd increases more than PI + Fs, the diaphragm is pressed down.
The shaft installed to the temperature sensor end presses down the ball valve.
The amount of refrigerant is increased.
If the refrigerant gas temperature from the evaporator decreases, the expansion valve decreases the amount of refrigerant flow according to the following operation:

The temperature of the temperature sensor tightly sealed against the diaphragm decreases.
The refrigerant temperature in the diaphragm decreases and the Pd decreases.
The Pd decreases less than PI + Fs.
The ball valve installed to the temperature sensor end is pressed up.
The amount of refrigerant is decreased.
Fail-safe
Function not equipped.
Evaporator Inspection
Expansion Valve Removal/InstallationLiftgate Opener System
Outline
A liftgate opener system has been adopted in which the liftgate can be opened
just by pressing the liftgate opener switch.
The rear body control module (RBCM) performs liftgate opener system fail-safe..
Function
When the liftgate opener switch is pressed, the l ...
Engine Oil Control
Outline
The PCM reduces the oil pump load applied to the engine by controlling the
appropriate engine hydraulic pressure according to the engine operation conditions.
The engine hydraulic pressure switches in two steps. When hydraulic pressure
is not needed, the oil pump dischar ...
Clutch Pedal Position Switch Removal/Installation [C66 M R]
1. Disconnect the negative battery cable..
2. Disconnect the clutch pedal position switch connector.
3. Rotate the clutch pedal position switch 45° counterclockwise.
4. Remove the clutch pedal position switch from the clutch pedal.
5. Insert a new clutch pedal position switch into t ...