NETWORKING: CAN COMMUNICATION SYSTEM: DESCRIPTION (2008 LX570)

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Last Modified: 11-27-2007		1.6 J
Service Category: Power Source/Network	Section: Networking
Model Year: 2008	Model: LX570	Doc ID: RM000002L8200EX
Title: NETWORKING: CAN COMMUNICATION SYSTEM: DESCRIPTION (2008 LX570)

Open in CAN Main Wire

DESCRIPTION

There may be an open circuit in the CAN main wire and/or DLC3 branch wire when the resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is 69 Ω or higher.

Symptom	Trouble Area
Resistance between terminals 6 (CANH) and 14 (CANL) of DLC3 is 69 Ω or higher.	CAN main wire and connector No. 1 junction connector No. 2 junction connector No. 3 junction connector ECM Combination meter assembly DLC3 branch wire or connector

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

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

PROCEDURE

1.	DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL

(a) 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 disable the SRS system.

NOTICE:

w/ Navigation System:

After the engine 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 engine 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 .

2.	CHECK DLC3

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

Result

Tester Connection	Switch Condition	Measured Resistance	Proceed to
E22-6 (CANH) - E22-14 (CANL)	Engine switch off	108 to 132 Ω	OK
E22-6 (CANH) - E22-14 (CANL)	Engine switch off	132 Ω or higher	NG

NOTICE:

When the measured value is 132 Ω or higher and a CAN communication system diagnostic trouble code is output, there may be a fault besides disconnection of the DLC3 branch wire. For that reason, troubleshooting should be performed again from "How to Proceed with Troubleshooting" after repairing the trouble area.

3.	CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 2 JUNCTION CONNECTOR - ECM)

(a) Disconnect the E69 No. 2 junction connector connector.

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

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
E69-1 (CANH) - E69-12 (CANL)	Engine switch off	108 to 132 Ω

4.	CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 2 JUNCTION CONNECTOR - COMBINATION METER)

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

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
E69-4 (CANH) - E69-15 (CANL)	Engine switch off	108 to 132 Ω

5.	CONNECT CONNECTOR

(a) Reconnect the E69 No. 2 junction connector connector.

6.	CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 1 JUNCTION CONNECTOR - ECM)

(a) Disconnect the E72 No. 1 junction connector connector.

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

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
E72-2 (CANH) - E72-13 (CANL)	Engine switch off	108 to 132 Ω

7.	CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 1 JUNCTION CONNECTOR - NO. 2 JUNCTION CONNECTOR)

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

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
E72-1 (CANH) - E72-12 (CANL)	Engine switch off	108 to 132 Ω

8.	CONNECT CONNECTOR

(a) Reconnect the E72 No. 1 junction connector connector.

9.	CHECK FOR OPEN IN CAN BUS MAIN WIRE (ECM - NO. 1 JUNCTION CONNECTOR)

(a) Disconnect the A38 ECM connector.

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

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
A38-10 (CANH) - A38-11 (CANL)	Engine switch off	108 to 132 Ω

10.	CONNECT CONNECTOR

(a) Reconnect the E69 No. 2 junction connector connector.

11.	CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 3 JUNCTION CONNECTOR - COMBINATION METER)

(a) Disconnect the E75 No. 3 junction connector connector.

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

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
E75-3 (CANH) - E75-14 (CANL)	Engine switch off	108 to 132 Ω

12.	CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 2 JUNCTION CONNECTOR - NO. 3 JUNCTION CONNECTOR)

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

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
E75-1 (CANH) - E75-12 (CANL)	Engine switch off	108 to 132 Ω

13.	CONNECT CONNECTOR

(a) Reconnect the E75 No. 3 junction connector connector.

14.	CHECK FOR OPEN IN CAN BUS MAIN WIRE (COMBINATION METER - NO. 3 JUNCTION CONNECTOR)

(a) Disconnect the E77 combination meter connector.

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

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
E77-36 (CANH) - E77-35 (CANL)	Engine switch off	108 to 132 Ω