Toyota CH-R Service Manual: Open in Bus 4 Main Bus Line

Toyota CH-R Service Manual / Networking / Can Communication System / Open in Bus 4 Main Bus Line

DESCRIPTION

There may be an open circuit in one of the CAN main bus lines when the resistance between terminals 22 (CA2H) and 7 (CA2L) of the central gateway ECU (network gateway ECU) is 70 Ω or higher.

Symptom

Trouble Area

Resistance between terminals 22 (CA2H) and 7 (CA2L) of the central gateway ECU (network gateway ECU) is 70 Ω or higher.
  • CAN main bus lines or connector
  • Central gateway ECU (network gateway ECU)
  • Airbag sensor assembly
  • No. 4 CAN junction connector
  • No. 5 CAN junction connector

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

WIRING DIAGRAM

CAUTION / NOTICE / HINT

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

  • Before measuring the resistance of the CAN bus, turn the ignition 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

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

    DTC check procedure: Turn the blind spot monitor system on using the blind spot monitor main switch (ON/OFF switch), turn the cruise control main switch on, turn the LDA main switch on and then drive the vehicle at a speed of 60 km/h (37 mph) or more for approximately 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

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 MAIN BUS LINES (NO. 5 CAN JUNCTION CONNECTOR)

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

(b) Disconnect the No. 5 CAN junction connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Connected to

F124-1 (CANH) - F124-12 (CANL)

Cable disconnected from negative (-) battery terminal

108 to 132 Ω

No. 4 CAN junction connector

F124-2 (CANH) - F124-13 (CANL)

Cable disconnected from negative (-) battery terminal

108 to 132 Ω

Central gateway ECU (network gateway ECU)

*a

Front view of wire harness connector

(to No. 5 CAN Junction Connector)

*b

to No. 4 CAN Junction Connector

*c

to Central Gateway ECU (Network Gateway ECU)

Result

Proceed to

OK

A

NG (Line to central gateway ECU (network gateway ECU))

B

NG (Line to No. 4 CAN junction connector)

C
A

REPLACE NO. 5 CAN JUNCTION CONNECTOR
C

GO TO STEP 3

B

2.

CHECK FOR OPEN IN CAN MAIN BUS LINES (CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) - NO. 5 CAN JUNCTION CONNECTOR)

(a) Reconnect the F124 No. 5 CAN junction connector.

(b) Disconnect the F74 central gateway ECU (network gateway ECU) connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

F74-22 (CA2H) - F74-7 (CA2L)

Cable disconnected from negative (-) battery terminal

108 to 132 Ω

*a

Front view of wire harness connector

(to Central Gateway ECU (Network Gateway ECU))
OK

REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU)

NG

REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) - NO. 5 CAN JUNCTION CONNECTOR)

3.

CHECK FOR OPEN IN CAN MAIN BUS LINES (NO. 4 CAN JUNCTION CONNECTOR)

(a) Reconnect the F124 No. 5 CAN junction connector.

(b) Disconnect the No. 4 CAN junction connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Connected to

F123-1 (CANH) - F123-12 (CANL)

Cable disconnected from negative (-) battery terminal

108 to 132 Ω

Airbag sensor assembly

F123-7 (CANH) - F123-18 (CANL)

Cable disconnected from negative (-) battery terminal

108 to 132 Ω

No. 5 CAN junction connector

*a

Front view of wire harness connector

(to No. 4 CAN Junction Connector)

*b

to Airbag Sensor Assembly

*c

to No. 5 CAN Junction Connector

Result

Proceed to

OK

A

NG (Line to No. 5 CAN junction connector)

B

NG (Line to Airbag sensor assembly)

C
A

REPLACE NO. 4 CAN JUNCTION CONNECTOR
B

REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (NO. 4 CAN JUNCTION CONNECTOR - NO. 5 CAN JUNCTION CONNECTOR)
C

4.

CHECK FOR OPEN IN CAN MAIN BUS LINES (AIRBAG SENSOR ASSEMBLY - NO. 4 CAN JUNCTION CONNECTOR)

(a) Reconnect the F123 No. 4 CAN junction connector.

(b) Disconnect the airbag sensor assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

F70-13 (CANH) - F70-22 (CANL)

Cable disconnected from negative (-) battery terminal

108 to 132 Ω

*a

Front view of wire harness connector

(to Airbag Sensor Assembly)
OK

REPLACE AIRBAG SENSOR ASSEMBLY

NG

REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (AIRBAG SENSOR ASSEMBLY - NO. 4 CAN JUNCTION CONNECTOR)
    Check Bus 4 Lines for Short Circuit
    DESCRIPTION There may be a short circuit between the CAN main bus lines and/or CAN branch lines when the resistance between terminals 22 (CA2H) and 7 (CA2L) of the central gateway ECU (network ga ...

    Check Bus 4 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 22 (CA2H) of the central gateway ECU (network gateway ECU) and terminal ...

    Other materials:

    Toyota CH-R Service Manual > Immobiliser System(w/o Smart Key System): Precaution
    PRECAUTION PRECAUTIONS WHEN USING TECHSTREAM (a) After all DTCs are cleared, check if the malfunction occurs again 6 seconds after turning the ignition switch ON. PRECAUTIONS FOR THE KEY (a) The key is a precision instrument. Be sure to observe the following: (1) Do not drop or strike the key ...

    Toyota CH-R Service Manual > Spiral Cable: Components
    COMPONENTS ILLUSTRATION *1 LOWER STEERING COLUMN COVER SUB-ASSEMBLY *2 SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY *3 UPPER STEERING COLUMN COVER - - ...

    Toyota C-HR (AX20) 2023-2025 Owner's Manual

    Toyota CH-R Owners Manual

    Toyota CH-R Service Manual

    © 2017-2025 Copyright www.tochr.net
    0.0108