Inspection Procedure

WARNING: This page is about a different car, the 2004 Lexus ES 330. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT HEATER CONTROL HOUSING SUB-ASSY(PSW)
1. Install the manifold gauge set.
2. Remove A/C amplifier with connectors still connected.
3. Turn ignition switch ON.
4. Check voltage between terminal PSW of A/C amplifier connector and body ground when refrigerant pressure is changed.
5. The voltage changes with refrigerant pressure, as shown in the diagram below.
  Voltage
  
  Fig 1: Checking Voltage Between Terminal PSW Of A/C Amplifier Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 2: Identifying Voltage Changes Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 3: Identifying Inspection Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE (SEE PROBLEM SYMPTOMS TABLE )

C: CHECK AND REPLACE HEATER CONTROL HOUSING SUB-ASSY

A: Go to next step.
INSPECT PRESSURE SWITCH
1. Disconnect pressure SW connector.
2. Turn ignition switch ON.
3. A/C switch ON.
4. Check continuity between terminals 1 and 4 of pressure switch when refrigerant pressure is changed.
5. The continuity changes with refrigerant pressure as shown in the diagram below.
  Continuity:
  
  Fig 4: Checking Continuity Between Terminals 1 And 4 Of Pressure Switch
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 5: Identifying Voltage Changes Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPLACE PRESSURE SWITCH

OK: Go to next step.
CHECK HARNESS AND CONNECTOR(BETWEEN PRESSURE SW AND HEATER CONTROL HOUSING SUB-ASSY)
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: CHECK AND REPLACE HEATER CONTROL HOUSING SUB-ASSY