On-Vehicle Inspection

WARNING: This page is about a different car, the 2003 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT COMPRESSOR FOR METALLIC SOUND
Check there is abnormal metallic sound from the compressor when the A/C switch is ON.

If abnormal metallic sound is heard, replace the compressor assembly.
INSPECT REFRIGERANT PRESSURE
(See ON-VEHICLE INSPECTION ).
INSPECT VISUALLY FOR LEAKAGE OF REFRIGERANT
Using a gas leak detector, check for leakage of refrigerant. If there is any leakage, replace the compressor assembly.
INSPECT COMPRESSOR LOCK SENSOR RESISTANCE
1. Disconnect the connector.
2. Measure resistance between terminals 1 and 2.
Standard Resistance: 160-320 Ω at 20 °C (68 °F)

If resistance is not as specified, replace the sensor.

Fig 1: Checking Compressor Lock Sensor Resistance
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
CHECK FOR LEAKAGE OF GREASE FROM CLUTCH BEARING
CHECK FOR SIGNS OF OIL ON PRESSURE PLATE OR ROTOR
INSPECT MAGNETIC CLUTCH BEARING FOR NOISE
1. Start engine.
2. Check for abnormal noise from the compressor when the A/C switch is OFF.
If abnormal noise is being emitted, replace the magnetic clutch.
INSPECT MAGNETIC CLUTCH OPERATION
1. Disconnect the connector.
2. Connect the positive (+) lead from the battery to terminal 3 and the negative (-) lead to the body ground.
3. Check that the magnetic clutch energized.
If operation is not as specified, replace the magnetic clutch.

Fig 2: Checking Magnetic Clutch Operation
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT SOLENOID OF THE EXTERNALLY CHANGEABLE COMPRESSOR
1. Disconnect the connector.
2. Measure resistance between terminals 1 and 2.
Standard Resistance: 10-11 Ω

If resistance is not specified, replace the compressor.

Fig 3: Measuring Externally Changeable Compressor Solenoid Resistance
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002