Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM1000000018DNA
Model Year Start: 2018 Model: Sienna Prod Date Range: [11/2017 -           ]
Title: NETWORKING: CAN COMMUNICATION SYSTEM: Open in Bus 3 Main Bus Line; 2018 - 2020 MY Sienna [11/2017 -        ]

Open in Bus 3 Main Bus Line

DESCRIPTION

There may be an open circuit in one of the bus 3 main lines when the resistance between terminals 6 (CA3H) and 21 (CA3L) of the central gateway ECU (network gateway ECU) is 70 Ω or higher.

Detection Item

Trouble Area

Resistance between terminals 6 (CA3H) and 21 (CA3L) of central gateway ECU (network gateway ECU) is 70 Ω or higher.
  • Bus 3 CAN main wire or connector
  • Central gateway ECU (network gateway ECU)
  • No. 4 junction connector

This malfunction is not related to the lines of a bus 3 branch or to ECUs or sensors connected a bus 3 branch.

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

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 (NO. 4 JUNCTION CONNECTOR)

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

(b) Disconnect the No. 4 junction connector.

*a

Front view of wire harness connector

(to No. 4 Junction Connector)

*b

to Central Gateway ECU (Network Gateway ECU)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Connected to

D204-8 (CANH) - D204-19 (CANL)

Cable disconnected from negative (-) battery terminal

108 to 132 Ω

Central gateway ECU (network gateway ECU)

D204-9 (CANH) - D204-20 (CANL)

Cable disconnected from negative (-) battery terminal

108 to 132 Ω

Central gateway ECU (network gateway ECU)
OK

REPLACE NO. 4 JUNCTION CONNECTOR
NG

2.

CHECK FOR OPEN IN CAN BUS WIRE (CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) - NO. 4 JUNCTION CONNECTOR)

(a) Reconnect the No. 4 junction connector.

(b) Disconnect the central gateway ECU (network gateway ECU) connector.

*a

Front view of wire harness connector

(to Central Gateway ECU (Network Gateway ECU))

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

D202-6 (CA3H) - D202-19 (CAYH)

Cable disconnected from negative (-) battery terminal

Below 1 Ω

D202-21 (CA3L) - D202-20 (CAYL)

Cable disconnected from negative (-) battery terminal

Below 1 Ω
OK

REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU)

NG

REPAIR OR REPLACE CAN MAIN BUS WIRE OR CONNECTOR (CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) - NO. 4 JUNCTION CONNECTOR)