Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM100000000VJE2
Model Year Start: 2016 Model: Sienna Prod Date Range: [12/2015 - 11/2017]
Title: NETWORKING: CAN COMMUNICATION SYSTEM: Main Body ECU Communication Stop Mode; 2016 - 2017 MY Sienna [12/2015 - 11/2017]

Main Body ECU Communication Stop Mode

DESCRIPTION

Detection Item

Symptom

Trouble Area

Main Body ECU Communication Stop Mode
  • "Main Body" not displayed on "Communication Bus Check" screen of Techstream
  • Applies to "Main Body ECU Communication Stop Mode" in "DTC combination table"
  • Power source circuit of main body ECU (multiplex network body ECU)
  • Main body ECU (multiplex network body ECU) branch wire or connector
  • Main body ECU (multiplex network body ECU)
  • Instrument panel 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.
  • 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 2016 MY Sienna [12/2015 - 08/2016]; INTRODUCTION: REPAIR INSTRUCTION: PRECAUTION 2017 - 2020 MY Sienna [08/2016 -        ]; INTRODUCTION: REPAIR INSTRUCTION: PRECAUTION ).

NEXT

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 2016 MY Sienna [12/2015 - 08/2016]; INTRODUCTION: REPAIR INSTRUCTION: INITIALIZATION 2017 MY Sienna [08/2016 - 11/2017]; INTRODUCTION: REPAIR INSTRUCTION: INITIALIZATION )

NEXT

3.

CHECK FOR OPEN IN CAN BUS WIRE (MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) BRANCH WIRE)

(a) Disconnect the main body ECU (multiplex network body ECU) connector.

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

D13-14 (CANH) - D13-13 (CANL)

Ignition switch off

54 to 69 Ω

Text in Illustration

*a

Front view of wire harness connector

(to Main Body ECU (Multiplex Network Body ECU))

(c) Reconnect the main body ECU (multiplex network body ECU) connector.

NG

REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) (CAN-H, CAN-L)
OK

4.

CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - POWER SOURCE)

(a) Disconnect the instrument panel block connectors.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

2D-28 - Body ground

Always

Below 1 Ω

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

2F-40 - Body ground

Always

11 to 14 V

Text in Illustration

*a

Front view of wire harness connector

(to Instrument Panel Junction Block Assembly)
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

5.

INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (IG SIGNAL CIRCUIT)

(a) Check the IG signal circuit (See page 2016 MY Sienna [12/2015 - 08/2016]; LIGHTING (INT): LIGHTING SYSTEM: IG Signal Circuit 2017 - 2020 MY Sienna [08/2016 -        ]; LIGHTING (INT): LIGHTING SYSTEM: IG Signal Circuit ).

OK

REPLACE MAIN BODY ECU

NG

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY