Inspection Procedure

WARNING: This page is about a different car, the 2007 Lexus ES 350. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

Turn the engine switch off before measuring the resistances of CAN bus main wires and CAN bus branch wires.
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 WIRE (MAIN BODY ECU BRANCH WIRE)

Turn the engine switch off.
Disconnect the main body ECU connector.

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

Standard resistance

RESISTANCE SPECIFICATION

Tester Connection	Condition	Specified Value
E59-5 (CANH) - E59-6 (CANL)	Engine switch off	54 to 69 Ω

Fig 1: Identifying Main Body ECU Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE CAN NO. 1 BUS BRANCH WIRE OR CONNECTOR (MAIN BODY ECU)

OK: Go to Next Step

CHECK HARNESS AND CONNECTOR (IG, GND1)

Disconnect connectors DF and DA from the instrument panel J/B.

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

Standard resistance

RESISTANCE SPECIFICATION

Tester Connection	Condition	Specified Value
DF-10 (GND1) - 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
DA-1 (B) - Body ground	Always	10 to 14 V

Fig 2: Identifying Instrument Panel J/B Connector Terminals

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE MAIN BODY ECU