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 E5 ECM, A9 A/C ECU and A21 airbag ECU connectors.
Check the resistance between the wire harness side connectors.

Standard:

TERMINAL SPECIFICATION

Terminal No.	Specified Condition
E5-18 (MPX1) - A9-3 (MPX-)	Below 1 Ω
E5-29 (MPX2) - A21-24 (MPX1)	Below 1 Ω

Fig 1: Checking Resistance Between Wire Harness Side Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

CHECK ECM (POWER SOURCE)

Disconnect the E5 and E4 ECM connectors.
Check the voltage between the wire harness side connector and body ground.

Standard:

TERMINAL SPECIFICATION

Terminal No.	Specified Condition
E5-6 (+BM) - Body ground	10 to 14 V
E4-3 (BATT) - Body ground	10 to 14 V

Fig 2: Disconnecting E5 & E4 ECM Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: Go to next step

CHECK ECM (GROUND)

Disconnect the E6 ECM connector.
Check the resistance between the wire harness side connector and body ground.

Standard:

TERMINAL SPECIFICATION

Terminal No.	Specified Condition
E6-1 (E1) - Body ground	Below 1 Ω
E6-4 (ME01) - Body ground	Below 1 Ω

Fig 3: Disconnecting E6 ECM Connector

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: REPLACE ECM