Toyota Venza: Main Body ECU Communication Stop Mode

Toyota Venza Service Manual / Networking / Can Communication System / Main Body ECU Communication Stop Mode

DESCRIPTION

Detection Item	Symptom	Trouble Area
Main Body ECU Communication Stop Mode	"Main Body" is not displayed on "CAN Bus Check" screen of the Techstream. Applies to Main Body ECU Communication Stop Mode in DTC Combination Table.	Power source circuit of main body ECU Main body ECU branch wire or connector Main body ECU (Driver side junction block)

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 CAN BUS WIRE FOR DISCONNECTION (MAIN BODY ECU BRANCH WIRE)

(a) Turn the ignition switch off.

(b) Disconnect the connector of the main body ECU.

Text in Illustration

*1	Front view of wire harness connector (to Main Body ECU)

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
D48-5 (CANH) - D48-6 (CANL)	Ignition switch off	54 to 69 Ω

REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (MAIN BODY ECU BRANCH WIRE)

2.	CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)

(a) Disconnect the connector of the driver side junction block.

Text in Illustration

*1	Front view of wire harness connector (to Driver Side Junction Block)

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
2C-24 (BECU) - Body ground	Always	11 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

3.	CHECK HARNESS AND CONNECTOR (GROUND TERMINAL)

(a) Disconnect the connector of the driver side junction block.

Text in Illustration

*1	Front view of wire harness connector (to Driver Side Junction Block)

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
2F-16 (GND1) - Body ground	Always	Below 1 Ω

REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK)

REPAIR OR REPLACE HARNESS OR CONNECTOR (GROUND CIRCUIT)

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