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 +B of A/C amplifier connector and body ground.
PREPARATION:

Remove the A/C amplifier with connector still connected.

CHECK:

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

OK:

Voltage: Battery voltage

Fig 1: Measuring Voltage Between Terminal +B Of A/C Amplifier 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 ECU-B1 fuse.
PREPARATION:

Remove ECU-B1 fuse from engine room J/B.

CHECK:

Check continuity of ECU-B1 fuse.

OK:

Continuity

Fig 2: Identifying ECU-B1 Fuse
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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 MPX-B fuse.
PREPARATION:

Remove MPX-B fuse from passenger side J/B.

CHECK:

Check continuity of MPX-B fuse.

OK:

Continuity

Fig 3: Identifying MPX-B Fuse
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: Check for short in all the harness and components connected to the MPX-B fuse (See attached wiring diagram).
2. OK: Check and repair harness and connector between A/C amplifier and battery.