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 TACHOMETER (OPERATION)
1. Check that the tachometer can operate properly while the engine is idling.
  OK: Tachometer can operate properly while the engine is idling.
OK: REPLACE COMBINATION METER ASSEMBLY

NG: Go to next step.

CHECK WIRE HARNESS (COMBINATION METER - BATTERY AND BODY GROUND)

Disconnect the C8 meter connector.

Fig 1: Identifying C8 Meter Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard voltage

VOLTAGE SPECIFICATION

Tester Connection	Specified Condition
C8-12 (+B) - Body ground	10 to 14 V

Standard resistance

RESISTANCE SPECIFICATION

Tester Connection	Specified Condition
C8-11 (ES) - Body ground	Below 1 Ω

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: Go to next step.

CHECK RESISTANCE OF COMMUNICATION LINE

Disconnect the C8 meter connector.
Disconnect the G3 and S6 ECU connectors.

Fig 2: Identifying C8 Meter Connector And G3 And S6 ECU Connectors
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the resistance of the wire harness side connectors.

Standard resistance

RESISTANCE SPECIFICATION

Tester Connection	Specified Condition
C8-2 (MPX+) - G3-16 (MPI2)	Below 1 Ω
C8-3 (MPX-) - S6-17 (MPX1)	Below 1 Ω

Result

RESULT CHART

Result	Proceed to
Both are OK	A
One is OK	B
Both are NG	C

B: REPLACE COMBINATION METER ASSEMBLY AND REPAIR OR REPLACE HARNESS AND CONNECTOR

C: REPAIR OR REPLACE HARNESS AND CONNECTOR

A: REPLACE COMBINATION METER ASSEMBLY