Inspection Procedure

WARNING: This page is about a different car, the 2008 Lexus LS 600hL. However, it is still accessible from the selected car via links, so may be relevant.

HINT:

Operating the power switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL
1. Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the main wire and the branch wire
CAUTION: Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to prevent airbag and seat belt pretensioner activation.
NOTE:
- After the power switch is turned OFF, the HDD navigation system requires approximately 6 minutes to record various types of memory and settings. As a result, after turning the power switch OFF, wait 6 minutes or more before disconnecting the cable from the negative (-) battery terminal.
- When disconnecting the cable, some systems need to be initialized after the cable is reconnected (see INITIALIZATION ).

CHECK FOR OPEN IN CAN BUS WIRE (MAIN BODY ECU BRANCH WIRE)

Disconnect the L11 main body ECU connector.
Measure the resistance according to the value (s) in the table below.
Standard resistance

RESISTANCE SPECIFICATION

Tester Connection	Switch Condition	Specified Condition
L11-5 (CANH) - L11-6 (CANL)	Power switch OFF	54 to 69 Ω

Fig 1: Identifying L11 Main Body ECU Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE MAIN BODY ECU BRANCH WIRE OR CONNECTOR (CANH, CANL)

OK: Go to Next Step

CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - BATTERY AND BODY GROUND)

Fig 2: Identifying Main Body ECU Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Connect the cable to the negative (-) battery terminal.
NOTE: When disconnecting the cable, some systems need to be initialized after the cable is reconnected (see INITIALIZATION ).
Disconnect the DA and DF main body ECU connectors.
Disconnect the L11 main body ECU connector.

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

Standard resistance

RESISTANCE SPECIFICATION

Tester Connection	Condition	Specified Condition
DA-40 (GND1) - Body ground	Always	Below 1 Ω
DA-40 (GND2) - Body ground	Always	Below 1 Ω
L11-1 (GND3) - DA-41 (GND1)	Always	Below 1 Ω

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

VOLTAGE SPECIFICATION

Tester Connection	Condition	Specified Condition
DF-1 (ALTB) - Body ground	Always	11 to 14 V

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE MAIN BODY ECU