Inspection Procedure

WARNING: This page is about a different car, the 2007 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT FUSE (AM1, MPX-IG)
1. Remove the AM1 and MPX-IG fuses from the driver side junction block.
2. Measure the resistance of the fuses.
  Standard resistance: Below 1 Ω
NG: REPLACE FUSE

OK: Go to next step.

INSPECT RELAY (Marking: IG1)

Fig 1: Inspecting IG1 Relay

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Remove the IG1 relay from the driver side junction block.

Measure the resistance of the relay.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Specified Condition
3 - 5	10 kΩ or higher
3 - 5	Below 1 Ω (when battery voltage is applied to terminals 1 and 2)

NG: REPLACE RELAY

OK: Go to next step.

CHECK WIRE HARNESS (A/C AMPLIFIER - BODY GROUND)

Disconnect the A10 amplifier connector.

Measure the voltage and resistance of the wire harness side connector.

Standard voltage

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Condition	Specified Condition
A10-1 (IG) - Body ground	Ignition switch ON	10 to 14 V

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Specified Condition
A10-14 (GND) - Body ground	Below 1 Ω

Fig 2: Identifying A10 Amplifier Connector

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE