Inspection Procedure

WARNING: This page is about a different car, the 2005 Lexus GS 430 and 2005 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.

Check voltage between terminal +B of A/C control assembly connector and body ground.
PREPARATION:

Remove the A/C control assembly with connector still connected.

CHECK:

Measure voltage between terminal +B of A/C control assembly connector and body ground.

Fig 1: Measuring Voltage Between Terminal + B Of A/C Control Assembly Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK:

Voltage: Battery positive voltage
1. OK: Proceed to next circuit inspection shown on problem symptoms table (See PROBLEM SYMPTOMS TABLE ).
2. NG: Go to next step.
Check ECU-B1 fuse.
PREPARATION:

Remove ECU-B1 fuse from Engine Room No. 1 R/B.

Fig 2: Identifying ECU-B1 Fuse From Engine Room No. 2 R/B
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

CHECK:

Check continuity of ECU-B1 fuse.

OK:

Continuity
1. NG: Check for short in all the harness and components connected to the ECU-B1 fuse (See attached wiring diagram).
2. OK: Go to next step.
Check ECU-B2 fuse.
PREPARATION:

Remove ECU-B2 fuse from Passenger Side J/B.

CHECK:

Check continuity of ECU-B2 fuse.

Fig 3: Identifying ECU-B2 Fuse From Passenger Side J/B
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK:

Continuity
1. NG: Check for short in all the harness and components connected to the ECU-B2 fuse .
2. OK: Check and repair harness and connector between A/C control assembly and battery.