INSPECT PRESSURE SWITCH
Tech Tips
The pressure switch is installed onto the air conditioning pipe, on the high pressure side.
When the switch detects a drop in refrigerant pressure, due to factors such as refrigerant leakage, it turns the magnet clutch off(*1)to prevent damage to the compressor.
When the switch detects abnormally high pressure in the air conditioning cycle, it turns the magnet clutch off(*1)to prevent damage to parts in the air conditioning cycle.
(*1): The ECM turns the magnet clutch on or off upon receiving the signal from the pressure switch.
As the pressure switch operates when there is a malfunction with the refrigerant pressure, its function cannot be inspected on-vehicle. Follow the procedure below to inspect it.
Check the refrigerant pressure in the air conditioning cycle.
(*2)Read the manifold gauge pressure when the conditions below are established.
Test conditions:
Engine running at 1,500 rpm
Blower speed control lever in HI position
Temperature control lever in COOL position
A/C switch ON
Air inlet mode damper set at recirculation
All doors fully open
| Standard pressure on high pressure side |
|---|
| 1.37 to 1.57 MPa (13.9 to 16.0 kgf*cm2, 198 to 228 psi) |
Tech Tips
If the refrigerant pressure is not within the standard range, inspect and repair the air conditioning cycle Click here.
Proceed to step(*2)if the refrigerant pressure is within the specified range.
If the refrigerant pressure is below 196 KPa (2.0 kgf*cm2, 28 psi), the amount of refrigerant in the air conditioning cycle may have decreased significantly for reasons such as gas leakage.
Check the air conditioning operation.
Disconnect the pressure switch connector.
Connect terminals 1 and 2 of the pressure switch connector on the vehicle wire harness side using a service wire.
Start the engine.
Turn the air conditioning switch on and check that the magnet clutch is turned on.
Check that the magnet clutch is turned off when disconnecting terminals 1 and 2 (that are connected in the previous step).
| Standard |
|---|
| Terminals 1 and 2 connected |
| Magnet clutch ON |
| Terminals 1 and 2 disconnected |
| Magnet clutch OFF |
Replace the pressure switch if the magnet clutch operates normally.
Inspect and repair the wire harness between the pressure switch and the ECM.