Toyota Venza: Open in CAN Main Bus Line

Toyota Venza Service Manual / Networking / Can Communication System / Open in CAN Main Bus Line

DESCRIPTION

There may be an open circuit in the CAN bus main wire and/or the DLC3 branch wire when the resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is 70 Ω or higher.

Symptom	Trouble Area
Resistance between terminals 6 (CANH) and 14 (CANL) of DLC3 is 70 Ω or higher.	DLC3 branch wire or connector CAN bus main wire or connector Combination meter ECM CAN No. 1 junction connector CAN No. 2 junction connector

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Turn the ignition switch off before measuring the resistances between CAN bus main wires and between CAN bus branch wires.
Turn the ignition switch off before inspecting CAN bus wires for a ground short.
After the ignition switch is turned off, check that the key reminder warning system and light reminder warning system are not operating.
Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the ignition 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.

HINT:

Operating the ignition switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.
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

1.	CHECK FOR OPEN IN CAN BUS WIRE (DLC3 BRANCH WIRE)

(a) Turn the ignition switch off.

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

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
D1-6 (CANH) - D1-14 (CANL)	Ignition switch off	108 to 132 Ω

Text in Illustration

DLC3

NOTICE:

When the measured value is 133 Ω or higher and a CAN communication system DTC 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 (See page ).

REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO DLC3

2.	CHECK FOR OPEN IN CAN BUS WIRE (ECM)

(a) for 1AR-FE engine:

(1) Disconnect the ECM connector (A49).

Text in Illustration

*1	Front view of wire harness connector (to ECM)

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

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
A49-13 (CANH) - A49-5 (CANL)	Ignition switch off	108 to 132 Ω

(b) for 2GR-FE engine:

(1) Disconnect the ECM connector (A41).

Text in Illustration

*2	Front view of wire harness connector (to ECM)

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

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
A41-10 (CANH) - A41-11 (CANL)	Ignition switch off	108 to 132 Ω

Result	Proceed to
OK (for 1AR-FE engine)	A
OK (for 2GR-FE engine)	B
NG	C

REPLACE ECM

3.	CHECK FOR OPEN IN CAN BUS WIRE (COMBINATION METER)

(a) Reconnect the ECM connector.

(b) Disconnect the combination meter connector (E1).

Text in Illustration

*1	Front view of wire harness connector (to Combination Meter)

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
E1-1 (CANH) - E1-9 (CANL)	Ignition switch off	108 to 132 Ω

REPLACE COMBINATION METER

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

(a) Reconnect the combination meter connector.

(b) Disconnect the CAN No. 1 junction connector (A44).

Text in Illustration

Front view of wire harness connector

(to CAN No. 1 Junction Connector)

to ECM

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
A44-4 (CANH) - A44-15 (CANL)	Ignition switch off	108 to 132 Ω

REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 1 J/C - ECM)

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

(a) Reconnect the CAN No. 1 junction connector (A44).

(b) Disconnect the CAN No. 1 junction connector (D56).

Text in Illustration

Front view of wire harness connector

(to CAN No. 1 Junction Connector)

to CAN No. 2 Junction Connector

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
D56-9 (CANH) - D56-20 (CANL)	Ignition switch off	108 to 132 Ω

REPLACE CAN NO. 1 JUNCTION CONNECTOR

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

(a) Reconnect the CAN No. 1 junction connector (D56).

(b) Disconnect the CAN No. 2 junction connector.

Text in Illustration

Front view of wire harness connector

(to CAN No. 2 Junction Connector)

to Combination Meter

to CAN No. 1 Junction Connector

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition	Connect to
D68-8 (CANH) - D68-19 (CANL)	Ignition switch off	108 to 132 Ω	Combination meter
D68-9 (CANH) - D68-20 (CANL)	Ignition switch off	108 to 132 Ω	CAN No. 1 junction connector

Result	Proceed to
OK	A
NG (to Combination meter main wire)	B
NG (to CAN No. 1 junction connector)	C

REPLACE CAN NO. 2 JUNCTION CONNECTOR

REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 1 JUNCTION CONNECTOR - COMBINATION METER)

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

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