Inspection Procedure

WARNING: This page is about a different car, the 2005 Toyota Sienna. However, it is still accessible from the selected car via links, so may be relevant.

CHECK RESISTANCE OF COMMUNICATION LINE

Disconnect the C10 meter, A9 A/C ECU and B7 ECU connectors.
Check the resistance between the wire harness side connectors.

Standard:

TERMINAL SPECIFICATION

Terminal No.	Specified Condition
C10-28 (MPX-) - A9-2 (MPX+)	Below 1 Ω
C10-29 (MPX+) - B7-21 (MPX2)	Below 1 Ω

Fig 1: Disconnecting C10 Meter, A9 A/C ECU & B7 ECU Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: Go to Next Step
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

CHECK COMBINATION METER ASSY (POWER SOURCE)

Disconnect the C10 meter connector.
Check the voltage between the wire harness side connector and body ground.

Standard:

TERMINAL SPECIFICATION

Terminal No.	Specified Condition
C10-12 (+B) - Body ground	10 to 14 V

Fig 2: Identifying C10 Meter Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: Go to Next Step

CHECK COMBINATION METER ASSY (GROUND)

Disconnect the C10 meter connector.
Check the resistance between the wire harness side connector and body ground.

Standard:

TERMINAL SPECIFICATION

Terminal No.	Specified Condition
C10-30 (ES) - Body ground	Below 1 Ω

Fig 3: Identifying C10 Meter Connector

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: REPLACE COMBINATION METER ASSY