Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM1000000018DLD
Model Year Start: 2018 Model: Sienna Prod Date Range: [11/2017 -           ]
Title: NETWORKING: CAN COMMUNICATION SYSTEM: Main Body ECU Communication Stop Mode; 2018 - 2020 MY Sienna [11/2017 -        ]

Main Body ECU Communication Stop Mode

DESCRIPTION

Detection Item

Symptom

Trouble Area

Main Body ECU Communication Stop Mode

Either condition is met:

  • Communication stop for "Main Body" is indicated on the "Communication Bus Check" screen of the Techstream.

    Click here 2018 MY Sienna [11/2017 - 08/2018]; NETWORKING: CAN COMMUNICATION SYSTEM: PROBLEM SYMPTOMS TABLE 2019 - 2020 MY Sienna [08/2018 -        ]; NETWORKING: CAN COMMUNICATION SYSTEM: PROBLEM SYMPTOMS TABLE

  • Communication system DTCs (DTCs that start with U) that correspond to "Main Body ECU Communication Stop Mode" in "DTC Combination Table" are output.

    Click here 2018 MY Sienna [11/2017 - 08/2018]; NETWORKING: CAN COMMUNICATION SYSTEM: DTC COMBINATION TABLE 2019 - 2020 MY Sienna [08/2018 -        ]; NETWORKING: CAN COMMUNICATION SYSTEM: DTC COMBINATION TABLE

  • Power source circuit of main body ECU (multiplex network body ECU)
  • Main body ECU (multiplex network body ECU) ground circuit
  • 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

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

NOTICE:

  • Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output.

    Click here 2018 - 2020 MY Sienna [11/2017 -        ]; NETWORKING: CAN COMMUNICATION SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING

  • Before measuring the resistance of the CAN bus, turn the engine switch off and leave the vehicle for 1 minute or more without operating the key or any switches, or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.
  • After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.

    Click here 2017 - 2020 MY Sienna [08/2016 -        ]; INTRODUCTION: REPAIR INSTRUCTION: PRECAUTION

  • Some parts must be initialized and set when replacing or removing and installing parts.

    Click here 2018 - 2020 MY Sienna [11/2017 -        ]; INTRODUCTION: REPAIR INSTRUCTION: INITIALIZATION

  • After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.

    DTC check procedure: Turn the ignition switch to ON and wait for 1 minute or more. Then operate the suspected malfunctioning system and drive the vehicle at 60 km/h (37 mph) or more for 5 minutes or more.

  • After the repair, perform the CAN bus check and check that all the ECUs and sensors connected to the CAN communication system are displayed as normal.

    Click here 2018 MY Sienna [11/2017 - 08/2018]; NETWORKING: CAN COMMUNICATION SYSTEM: DIAGNOSIS SYSTEM 2019 - 2020 MY Sienna [08/2018 -        ]; NETWORKING: CAN COMMUNICATION SYSTEM: DIAGNOSIS SYSTEM

  • Before replacing the main body ECU (multiplex network body ECU), refer to Registration.

    Click here 2017 - 2020 MY Sienna [08/2016 -        ]; THEFT DETERRENT / KEYLESS ENTRY: ENGINE IMMOBILISER SYSTEM(w/ Smart Key System): REGISTRATION

  • Inspect the fuses for circuits related to this system before performing the following procedure.

HINT:

  • Before disconnecting related connectors for inspection, push in on each connector body to check that the connector is not loose or disconnected.
  • When a connector is disconnected, check that the terminals and connector body are not cracked, deformed or corroded.

PROCEDURE

1.

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

(a) Disconnect the cable from the negative (-) battery terminal.

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

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

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

Cable disconnected from negative (-) battery terminal

54 to 69 Ω

Text in Illustration

*a

Front view of wire harness connector

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

(d) 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)

OK

2.

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

Cable disconnected from negative (-) battery terminal

Below 1 Ω

(c) Reconnect the cable to the negative (-) battery terminal.

NOTICE:

When disconnecting the cable, some systems need to be initialized the cable is reconnected.

Click here 2018 - 2020 MY Sienna [11/2017 -        ]; INTRODUCTION: REPAIR INSTRUCTION: INITIALIZATION

(d) 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

3.

INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (IG SIGNAL CIRCUIT)

(a) Check the IG signal circuit (See page 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