Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM1000000018DNC
Model Year Start: 2018 Model: Sienna Prod Date Range: [11/2017 -           ]
Title: NETWORKING: CAN COMMUNICATION SYSTEM: Check Bus 3 Line for Short to +B; 2018 - 2020 MY Sienna [11/2017 -        ]

Check Bus 3 Line for Short to +B

DESCRIPTION

There may be a short circuit between one of the CAN bus lines and +B when no resistance exists between terminal 6 (CA3H) of the central gateway ECU (network gateway ECU) and terminal 16 (BAT) of the DLC3, or terminal 21 (CA3L) of the central gateway ECU (network gateway ECU) and terminal 16 (BAT) of the DLC3.

Detection Item

Trouble Area

No resistance exists between terminal 6 (CA3H) of the central gateway ECU (network gateway ECU) and terminal 16 (BAT) of the DLC3, or terminal 21 (CA3L) of the central gateway ECU (network gateway ECU) and terminal 16 (BAT) of the DLC3.
  • Short to +B in bus 3 CAN main wires
  • Short to +B in bus 3 CAN branch wires
  • Central gateway ECU (network gateway ECU)
  • Radio and display receiver assembly
  • DCM (telematics transceiver)*
  • No. 4 junction connector
  • *: w/ Telematics Transceiver

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 DCM (telematics transceiver), refer to Registration.

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

  • The following may occur if a radio and display receiver assembly from another vehicle is installed to this vehicle. Therefore, when replacing the radio and display receiver assembly, be sure to replace it with a new one.
    • A communication malfunction DTC is stored.
    • The radio and display receiver assembly does not operate normally.

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 SHORT TO +B IN CAN BUS LINE (NO. 4 JUNCTION CONNECTOR)

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

(b) Disconnect the No. 4 junction connector.

*1

DLC3

-

-

*a

Front view of wire harness connector

(to No. 4 Junction Connector)

*b

to Central Gateway ECU (Network Gateway ECU)

*c

to DCM (Telematics Transceiver)

(w/ Telematics Transceiver)

*d

to Radio and Display Receiver Assembly

(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) - D16-16 (BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

Central gateway ECU (network gateway ECU)

D204-19 (CANL) - D16-16 (BAT)

D204-10 (CANH) - D16-16 (BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

DCM (telematics transceiver)*

D204-21 (CANL) - D16-16 (BAT)

D204-11 (CANH) - D16-16 (BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

Radio and display receiver assembly

D204-22 (CANL) - D16-16 (BAT)

D204-9 (CANH) - D16-16 (BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

Central gateway ECU (network gateway ECU)

D204-20 (CANL) - D16-16 (BAT)
  • *: w/ Telematics Transceiver

Result

Proceed to

OK

A

NG (Central gateway ECU (network gateway ECU) main wire)

B

NG (ECU or sensor CAN branch wires)

C
A

REPLACE NO. 4 JUNCTION CONNECTOR
C

GO TO STEP 3

B

2.

CHECK FOR SHORT TO B+ IN CAN BUS WIRE (CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU))

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

*1

DLC3

-

-

*a

Front view of wire harness connector

(to Central Gateway ECU (Network Gateway ECU))

-

-

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

D202-6 (CA3H) - D16-16 (BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

D202-21 (CA3L) - D16-16 (BAT)

D202-19 (CAYH) - D16-16 (BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

D202-20 (CAYL) - D16-16 (BAT)
OK

REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU)

NG

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

3.

CHECK FOR SHORT TO +B IN CAN BUS WIRE (ECU, SENSOR)

(a) Reconnect all wire harness connectors.

(b) Disconnect the connector that includes terminals CANH and CANL from the ECU or sensor to which the bus line shorted to +B is connected.

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

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

D202-6 (CA3H) - D16-16 (BAT)

Cable disconnected from negative (-) battery terminal

6 kΩ or higher

D202-21 (CA3L) - D16-16 (BAT)

HINT:

If the resistance changes to 6 kΩ or higher when the connector is disconnected from the ECU or sensor, there may be a short in the ECU or sensor.

*1

DLC3

*a

Component with harness connected

(Central Gateway ECU (Network Gateway ECU))
OK

REPLACE CORRESPONDING ECU OR SENSOR
NG

REPAIR OR REPLACE CORRESPONDING ECU OR SENSOR CAN BRANCH WIRES OR CONNECTOR