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 RADIO RECEIVER ASSEMBLY

Disconnect the R3 receiver connector.

Fig 1: Identifying R3 Receiver Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the resistance of the receiver.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Specified Condition
R3-5 (TX+) - R3-15 (TX-)	60 to 80 Ω

NG: REPLACE RADIO RECEIVER ASSEMBLY

OK: Go to next step

CHECK WIRE HARNESS (RADIO RECEIVER - STEREO COMPONENT AMPLIFIER)

Disconnect the R3 receiver connector.

Fig 2: Identifying R3 Receiver Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Disconnect the S23 amplifier connector.

Measure the resistance of the wire harness side connectors.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Specified Condition
R3-5 (TX+) - S23-6 (TDX+)	Below 1 Ω
R3-15 (TX-) - S23-19 (TDX-)	Below 1 Ω
R3-5 (TX+) - Body ground	10 kΩ or higher
R3-15 (TX-) - Body ground	10 kΩ or higher

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: Go to next step

INSPECT STEREO COMPONENT AMPLIFIER ASSEMBLY
1. Temporarily replace the amplifier with a new or normally functioning amplifier.
2. Turn the ignition switch to ACC and check that the amplifier is functioning properly by operating the radio receiver switches.
  OK:
  
  Amplifier can be operated by radio receiver switches.
OK: END

NG: Go to next step
INSPECT RADIO RECEIVER ASSEMBLY
1. Temporarily replace the radio receiver with a new or normally functioning radio receiver.
2. Turn the ignition switch to ACC and check that the radio receiver switches are functioning properly.
  OK:
  
  Radio receiver switches are functioning properly.
OK: END

NG: Go to next step

CHECK WIRE HARNESS (RADIO RECEIVER - GATEWAY ECU)

Disconnect the R1 receiver connector.
Disconnect the G3 ECU connector.

Fig 3: Identifying G3 ECU Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the resistance of the wire harness side connector.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

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

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

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