Refrigerant Pressure Sensor / Switch: Testing and Inspection

ON-VEHICLE INSPECTION




1. INSPECT PRESSURE SWITCH (for magnet clutch control)
a. Check the air conditioning operation.
1. Disconnect the pressure switch connector.
2. Connect terminals 1 and 4 of the connector of the pressure switch on the vehicle wire harness side using a service wire.
3. Start the engine.
4. Turn the air conditioning switch on and check that the magnet clutch is turned on.
5. Check that the magnet clutch is turned off when disconnecting terminals 1 and 4 (that were connected in the previous step).
Standard:Terminals 1 and 4 are connected: magnet clutch is on
Terminals 1 and 4 are disconnected: magnet clutch is off Replace the pressure switch if the magnet clutch is operated normally.
Inspect and repair the wire harness between the pressure switch and the ECM.




2. INSPECT PRESSURE SWITCH (for cooling fan control)

HINT: The switch turns the condenser fan on or off in accordance with pressure in the cycle so that heat exchange in the condenser can be performed effectively within the normal pressure range.

a. Set the manifold gauge.
b. Disconnect the pressure switch connector and connect terminals 1 and 4 using a tool such as a service wire.
c. Connect the positive (+) lead from the ohmmeter to terminal 2 and the negative (-) lead to terminal 3.
d. Start the engine and turn the air conditioning switch on.
e. Check that the continuity between terminals 2 and 3 changes in accordance with the refrigerant pressure as shown in the illustration.
If the operation is not as specified, replace the pressure switch.