NETWORKING: CAN COMMUNICATION SYSTEM: 4WD Control ECU Communication Stop Mode; 2017 MY Sienna [08/2016

Last Modified: 04-05-2023	6.11:8.1.0	Doc ID: RM100000000Z14P
Model Year Start: 2017	Model: Sienna	Prod Date Range: [08/2016 - 11/2017]
Title: NETWORKING: CAN COMMUNICATION SYSTEM: 4WD Control ECU Communication Stop Mode; 2017 MY Sienna [08/2016 - 11/2017]

4WD Control ECU Communication Stop Mode

DESCRIPTION

Detection Item	Symptom	Trouble Area
4WD Control ECU Communication Stop Mode	"Four Wheel Drive Control" is not displayed on "CAN Bus Check" screen of Techstream Applies to "4WD Control ECU Communication Stop Mode" in "DTC combination table"	Power source or inside 4WD ECU assembly 4WD ECU assembly branch wire and connector 4WD ECU assembly

HINT:

For AWD without smart key system only.

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 (4WD ECU ASSEMBLY BRANCH WIRE)

(a) Disconnect the 4WD ECU assembly connector.

*a	Front view of wire harness connector (to 4WD ECU Assembly)

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

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
K1-14 (CANH) - K1-16 (CANL)	Ignition switch off	54 to 69 Ω

REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO 4WD ECU ASSEMBLY (CAN-H, CAN-L)

4.	CHECK WIRE HARNESS (4WD ECU ASSEMBLY - POWER SOURCE)

(a) Connect the cable to the negative (-) battery terminal.

NOTICE:

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

(b) Disconnect the 4WD ECU assembly connector.

*a	Front view of wire harness connector (to 4WD ECU Assembly)

Standard Resistance:

Tester Connection	Condition	Specified Condition
K1-23 (GND) - Body ground	Always	Below 1 Ω

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
K1-9 (BSLC) - Body ground	Always	11 to 14 V
K1-11 (IG1) - Body ground	Ignition switch ON	11 to 14 V

REPLACE 4WD ECU ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR