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 terminals IG and GND of A/C amplifier connector.
PREPARATION:
1. Remove A/C amplifier with connectors still connected.
2. Turn ignition switch to ON.
CHECK:

Measure voltage between terminals IG and GND of A/C amplifier.

OK:

Voltage: 10 - 14 V

Fig 1: Measuring Voltage Between Terminals IG And GND Of A/C Amplifier
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 amplifier and body ground.
CHECK:

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

OK:

Resistance: 0 Ω (Continuity)

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

Remove ECU-IG fuse from driver side J/B.

CHECK:

Check continuity of ECU-IG fuse.

OK:

Continuity exists.

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