CAN COMMUNICATION SYSTEM Open in Bus 2 Main Bus Line

DTC Code	DTC Name
	Open in Bus 2 Main Bus Line

DESCRIPTION

There may be an open circuit in one of the bus 2 main lines and/or a network gateway ECU CAN branch wire when the resistance between terminals 18 (CA4H) and 17 (CA4L) of the network gateway ECU is 70 Ω or higher


Detection Item	Trouble Area
Resistance between terminals 18 (CA4H) and 17 (CA4L) of network gateway ECU is 70 Ω or higher.	Bus 2 CAN main wire or connector Bus 2 CAN branch wire or connector ECM Combination meter assembly Network gateway ECU No. 1 CAN junction connector No. 2 CAN junction connector No. 3 CAN junction connector

This malfunction is not related to the lines of a bus 2 branch except the network gateway ECU CAN branch wires or to ECUs or sensors connected a bus 2 branch.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

Note:

Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output (Click here).
Before measuring the resistance of the CAN bus, turn the ignition switch off and leave the vehicle for 1 minute or more without operating the key, switches or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.
After turning the ignition switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work (Click here).
After the repair, perform CAN Bus Check and check that all the ECUs and sensors connected to the CAN communication system are displayed (Click here).

Tip:

Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.
Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE

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

Disconnect the cable from the negative (-) battery terminal.
Disconnect the ECM connector.

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

Standard Resistance

Table 1. for 1ZR-FAE, 2ZR-FAE
Tester Connection	Condition	Specified Condition
A76-13 (CANH) - A76-26 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

Table 2. for 1WW
Tester Connection	Condition	Specified Condition
A76-26 (CANH) - A76-25 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

Table 3. Text in Illustration
*A	for 1ZR-FAE, 2ZR-FAE
*B	for 1WW
*a	Front view of wire harness connector (to ECM)

Table 4. Result
Result	Proceed to
OK (for 1ZR-FAE)	A
OK (for 2ZR-FAE)	B
OK (for 1WW)	C
NG	D

REPLACE ECM

(Click here)

REPLACE ECM

(Click here)

REPLACE ECM

(Click here)

CONNECT CONNECTOR
1. Reconnect the A76 ECM connector.

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

Disconnect the combination meter assembly connector.

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

Standard Resistance


Tester Connection	Condition	Specified Condition
H62-22 (CANH) - H62-23 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

Table 5. Text in Illustration
*a	Front view of wire harness connector (to Combination Meter Assembly)

REPLACE COMBINATION METER ASSEMBLY

(Click here)

CONNECT CONNECTOR
1. Reconnect the H62 combination meter assembly connector.

CHECK FOR OPEN IN CAN BUS WIRE (NETWORK GATEWAY ECU - NO. 3 CAN JUNCTION CONNECTOR)

Disconnect the network gateway ECU connector.

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

Standard Resistance


Tester Connection	Condition	Specified Condition
H131-18 (CA4H) - H131- 17 (CA4L)	Cable disconnected from negative (-) battery terminal	54 to 69 Ω

Table 6. Text in Illustration
*a	Front view of wire harness connector (to Network Gateway ECU)

Table 7. Result
Result	Proceed to
OK (for LHD)	A
OK (for RHD)	B
NG	C

REPLACE NETWORK GATEWAY ECU

(Click here)

REPLACE NETWORK GATEWAY ECU

(Click here)

CONNECT CONNECTOR
1. Reconnect the H131 network gateway ECU connector.

CHECK FOR OPEN IN CAN BUS WIRE (NO. 1 CAN JUNCTION CONNECTOR)

Disconnect the No. 1 CAN junction connector.

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

Standard Resistance


Tester Connection	Condition	Specified Condition	Connect to
A50-9 (CANH) - A50-20 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω	No. 2 CAN junction connector
A50-10 (CANH) - A50-21 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω	ECM

Table 8. Text in Illustration
*a	Rear view of wire harness connector (to No. 1 CAN Junction Connector)
*b	to No. 2 CAN Junction Connector
*c	to ECM

Table 9. Result
Result	Proceed to
OK	A
NG (ECM CAN main wire)	B
NG (No. 2 CAN junction connector CAN main wire)	C

REPLACE NO. 1 CAN JUNCTION CONNECTOR

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 1 CAN JUNCTION CONNECTOR - ECM)

CONNECT CONNECTOR
1. Reconnect the A50 No. 1 CAN junction connector.

CHECK FOR OPEN IN CAN BUS WIRE (NO. 2 CAN JUNCTION CONNECTOR)

Disconnect the No. 2 CAN junction connector.

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

Standard Resistance


Tester Connection	Condition	Specified Condition	Connect to
Q13-2 (CANH) - Q13-8 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω	No. 3 CAN junction connector
Q13-3 (CANH) - Q13-9 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω	No. 1 CAN junction connector

Table 10. Text in Illustration
*a	Front view of wire harness connector (to No. 2 CAN Junction Connector)
*b	to No. 3 CAN Junction Connector
*c	to No. 1 CAN Junction Connector

Table 11. Result
Result	Proceed to
OK	A
NG (No. 1 CAN junction connector CAN main wire)	B
NG (No. 3 CAN junction connector CAN main wire)	C

REPLACE NO. 2 CAN JUNCTION CONNECTOR

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 2 CAN JUNCTION CONNECTOR - NO. 1 CAN JUNCTION CONNECTOR)

CONNECT CONNECTOR
1. Reconnect the Q13 No. 2 CAN junction connector.

CHECK FOR OPEN IN CAN BUS WIRE (NO. 3 CAN JUNCTION CONNECTOR)

Disconnect the No. 3 CAN junction connector.

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

Standard Resistance


Tester Connection	Condition	Specified Condition	Connect to
H88-4 (CANH) - H88-15 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω	No. 2 CAN junction connector
H88-7 (CANH) - H88-18 (CANL)	Cable disconnected from negative (-) battery terminal	200 Ω or higher	Network gateway ECU
H88-9 (CANH) - H88-20 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω	Combination meter assembly

Table 12. Text in Illustration
*a	Rear view of wire harness connector (to No. 3 CAN Junction Connector)
*b	to No. 2 CAN Junction Connector
*c	to Network Gateway ECU
*d	to Combination Meter Assembly

Table 13. Result
Result	Proceed to
OK	A
NG (No. 2 CAN junction connector CAN main wire)	B
NG (Network gateway ECU CAN branch wire)	C
NG (Combination meter assembly CAN main wire)	D

REPLACE NO. 3 CAN JUNCTION CONNECTOR

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 3 CAN JUNCTION CONNECTOR - NO. 2 CAN JUNCTION CONNECTOR)

REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (NO. 3 CAN JUNCTION CONNECTOR - NETWORK GATEWAY ECU)

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 3 CAN JUNCTION CONNECTOR - COMBINATION METER ASSEMBLY)