NETWORKING: CAN COMMUNICATION SYSTEM: ECM Communication Stop Mode; 2017 MY Sienna [08/2016

Last Modified: 04-05-2023	6.11:8.1.0	Doc ID: RM100000000Z14O
Model Year Start: 2017	Model: Sienna	Prod Date Range: [08/2016 - 11/2017]
Title: NETWORKING: CAN COMMUNICATION SYSTEM: ECM Communication Stop Mode; 2017 MY Sienna [08/2016 - 11/2017]

ECM Communication Stop Mode

DESCRIPTION

Detection Item	Symptom	Trouble Area
ECM Communication Stop Mode	"ECM (Engine)" not displayed on "Communication Bus Check" of 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.
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

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.	PRECAUTION

NOTICE:

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 (See page ).

2.	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:

When disconnecting the cable, some systems need to be initialized after the cable is reconnected (See page )

3.	CHECK CAN BUS LINE FOR DISCONNECTION (ECM MAIN WIRE)

(a) Disconnect the ECM connector.

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

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

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
A69-13 (CANH) - A69-26 (CANL)	Ignition switch off	108 to 132 Ω

REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO ECM (CAN-H, CAN-L)

4.	CHECK ECM POWER SOURCE CIRCUIT

(a) Check the ECM power source circuit (See page ).

REPLACE ECM

REPAIR OR REPLACE HARNESS OR CONNECTOR