ECM Communication Stop Mode (TO 12/2010): Procedure

CHECK CAN BUS WIRE (ECM MAIN BUS LINE DISCONNECTION)

Turn the ignition switch off.

Fig 1: Identifying ECM Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Disconnect the ECM connector (A55).

Measure the resistance according to the value(s) in the table below.

Standard resistance

Tester Connection	Condition	Specified value
A55-41 (CANH) - A55-49 (CANL)	Ignition switch off	108 to 132 Ω

NG → REPAIR OR REPLACE ECM MAIN BUS LINE OR CONNECTOR

OK: Go to next step

CHECK ENGINE ECU POWER SOURCE CIRCUIT
1. Check the ECM power source circuit. Refer to ECM Power Source Circuit .
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK → See step 3
REPLACE ECM. Refer to REMOVAL