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.

CHECK WIRE HARNESS (GATEWAY ECU - RADIO RECEIVER)

Disconnect the G3 ECU connector.

Fig 1: Identifying G3 ECU Connector Terminals
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Disconnect the R1 receiver connector.

Measure the resistance of the wire harness side connectors.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Specified Condition
G3-6 (GTX+) - R1-3 (TXS+)	Below 1 Ω
G3-21 (GTX-) - R1-6 (TXS-)	Below 1 Ω
G3-6 (GTX+) - Body ground	10 kΩ or higher
G3-21 (GTX-) - Body ground	10 kΩ or higher

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE OR DIAGNOSTIC TROUBLE CODE CHART