Inspection Procedure

NOTE:

Turn the engine switch off before measuring the resistances of CAN bus main wires and CAN bus branch wire.
After the engine switch is turned off, check that the key reminder warning system and light reminder warning system are not in operation.
Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the engine switch, any other switches, or the doors. If any doors need to be opened in order to check connectors, open the doors and leave them open.

CHECK OPEN IN CAN NO. 1 BUS MAIN WIRE (ECM MAIN WIRE)

Turn the engine switch off.
Disconnect ECM connectors A10.

Fig 1: Identifying ECM Connector A10 Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard Resistance

RESISTANCE REFERENCE

Tester Connection	Condition	Specified Value
A10-41 (CANH) - A10-49 (CANL)	Engine switch off	108 to 132 Ω

NG: REPAIR OR REPLACE CAN NO. 1 BUS MAIN WIRE OR CONNECTOR (ECM)

OK: Go to next step

CHECK WIRE HARNESS (+B, +B2, E1)

Disconnect ECM connector B12

Fig 2: Identifying ECM Connectors A10 And B12
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard Resistance

RESISTANCE REFERENCE

Tester Connection	Condition	Specified Value
B12-81 (E1) - Body ground	Always	Below 1 Ω

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

Standard Voltage

VOLTAGE SPECIFICATION

Tester Connection	Condition	Specified Value
A10-1 (+B2) - Body ground	Engine switch off	10 to 14 V
A10-2 (+B) - Body ground	Engine switch off	10 to 14 V

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE ECM (See REMOVAL )