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 (COMBINATION METER - NAVIGATION ECU)

Disconnect the N3 ECU connector.

Fig 1: Identifying N3 ECU Connector Terminals
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Disconnect the C8 meter connector.

Measure the resistance of the wire harness side connectors.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Specified Condition
N3-5 (SPD) - C8-21 (+S)	Below 1 Ω
N3-5 (SPD) - Body ground	10 kΩ or higher

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: Go to next step

CHECK COMBINATION METER ASSEMBLY (+S VOLTAGE)

Fig 2: Identifying Combination Meter Assembly Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Move the shift lever to N.
Jack up either of the rear wheels.

Measure the voltage of the meter connector.

Standard

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Condition	Specified Condition
C8-21 (+S) - Body ground	Ignition switch ON, rear wheels is turned slowly	Voltage pulses as shown below

NG: GO TO COMBINATION METER

OK: REPLACE NAVIGATION ECU