Toyota Venza: ECM Communication Stop Mode

Toyota Venza Service Manual / Networking / Can Communication System / ECM Communication Stop Mode

DESCRIPTION

Detection Item	Symptom	Trouble Area
ECM Communication Stop Mode	"Engine" and "ECT" are not displayed on "CAN Bus Check" screen of the Techstream. Applies to ECM Communication Stop Mode in DTC Combination Table.	Power source circuit of ECM ECM main wire or connector ECM

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 (ECM MAIN WIRE)

(a) Turn the ignition switch off.

(b) for 1AR-FE engine:

(1) Disconnect the connector of the ECM.

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

(1) Disconnect the connector of the ECM.

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

REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (ECM MAIN WIRE)

2.	CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)

(a) Check for ECM Power Source Circuit (1AR-FE: See page , 2GR-FE: See page
).

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

REPLACE ECM

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

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