Inspection Procedure

WARNING: This page is about a different car, the 2003 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.

Check voltage between terminal LCKI of ECM and body ground.
CHECK:
1. Start the engine.
2. Switch the blower dial to AUTO.
3. Measure voltage between terminal LCKI of ECM connector and body ground when A/C switch is ON.
OK:

Voltage: 10 - 14 V

Fig 1: Measuring Voltage Between Terminal LCKI Of ECM Connector And Body Ground
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. OK: Proceed to next circuit inspection shown on problem symptoms table (See PROBLEM SYMPTOMS TABLE ).
2. NG: Go to next step.
Check compressor lock sensor.
PREPARATION:

Disconnect compressor lock sensor connector.

CHECK:

Measure resistance between terminals 1 and 2 of compressor lock sensor connector.

OK:

Resistance:

at 20°C (68°F): 990 - 1210 Ω

at 100°C (212°F): 1280 - 1550 Ω

Fig 2: Measuring Resistance Between Terminals 1 And 2 Of Compressor Lock Sensor Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: Replace compressor lock sensor.
2. OK: Go to next step.
Check harness and connectors between ECM and compressor lock sensor (INSPECTION, Connectors, Terminal pins, Wiring Harness (Open or Short Circuits)).
1. NG: Repair or replace harness or connector.
2. OK: Go to next step.
Check harness and connectors between ECM and A/C amplifier (INSPECTION, Connectors, Terminal pins, Wiring Harness (Open or Short Circuits)).
1. NG: Repair or replace harness or connector.
2. OK: Check and replace ECM.