Inspection Procedure

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.

Check voltage between terminal IG and GND of A/C ECU connector.
PREPARATION:

Remove the A/C ECU with connectors still connected.

CHECK:
1. Turn ignition switch to ON.
2. Measure voltage between terminals IG and GND of A/C ECU.
OK:

Voltage: Battery positive voltage

Fig 1: Identifying Terminal IG And Gnd Of A/C ECU Connector
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 continuity between terminal GND of A/C ECU and body ground.
CHECK:

Measure resistance between terminal GND of A/C ECU and body ground.

OK:

Resistance: 0 Ω. (continuity)

Fig 2: Identifying Terminal Gnd Of A/C ECU And Body Ground
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG : Repair or replace harness or connector.
2. OK : Go to next step.
Check P-IG fuse.
PREPARATION:

Remove P-IG fuse from passenger side J/B.

CHECK:

Check continuity of P-IG fuse.

OK:

Continuity exists

Fig 3: Identifying P-IG Fuse
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG : Check for short in all the harness and components connected to the P-IG fuse.
2. OK : Check and repair harness and connector between A/C ECU and battery.