Inspection Procedure

WARNING: This page is about a different car, the 2002 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.

Check voltage between terminals PSW of A/C amplifier and body ground.
Preparation
1. Install the manifold gauge set. See SET ON MANIFOLD GAUGE SET .
2. Remove the center cluster module control with connectors still connected.
3. Turn ignition switch ON.
  Check: voltage between terminals PSW of A/C amplifier connector and body ground when refrigerant pressure is changed.
  
  If OK , the voltage changes refrigerant pressure, as shown in Fig 1.
  
  Fig 1: Charting A/C Amplifier Voltage & Refrigerant Pressure Specifications
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 2: Locating A/C Amplifier Terminal PSW
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. If OK , proceed to next circuit inspection shown on problem symptoms table. See PROBLEM SYMPTOMS TABLE .
2. NG: Go to step 2 .
Check pressure switch.
PREPARATION: Disconnect pressure switch connector.

Check: continuity between terminals 1 and 4 of pressure switch when refrigerant is changed.

If OK , the continuity changes with refrigerant pressure as shown in Fig 3.

Fig 3: Charting Pressure Switch Status & Refrigerant Pressure Specifications
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 4: Locating Pressure Switch & Identifying Pressure Switch Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: Replace pressure switch.
2. OK: Go to step 3 .
Check harness and connector between A/C amplifier and pressure switch, pressure switch and body ground . See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION .
1. NG : Repair or replace harness or connector.
2. If OK , check and replace A/C amplifier.