Can Communication System (For Sedan) Main Body Ecu Communication Stop Mode

Power Source Network. Yaris. Ncp93, 131
Networking. Yaris. Ncp93, 131

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK CAN BUS LINE FOR DISCONNECTION (MAIN BODY ECU BRANCH WIRE)

CHECK HARNESS AND CONNECTOR (BECU, IG, GND1)

CAN COMMUNICATION SYSTEM (for Sedan) - Main Body ECU Communication Stop Mode


DESCRIPTION


Detection Item
Symptom
Trouble Area
Main Body ECU Communication Stop Mode
  1. "Main Body" not displayed on "Communication Bus Check" screen of Techstream
  2. Applies to "Main Body ECU Communication Stop Mode" in "DTC combination table"
  1. Power source circuit of main body ECU
  2. Main body ECU branch wire or connector
  3. Main body ECU

WIRING DIAGRAM


Yaris. Ncp93, 131.Networking.Can Communication System (For Sedan).Can Communication System (For Sedan) Main Body Ecu Communication Stop Mode


INSPECTION PROCEDURE

NOTICE:
  1. Turn the ignition switch OFF before measuring the resistances of the CAN main wire and the CAN branch wire.
  2. After the ignition switch is turned off, check that the key reminder warning system and light reminder warning system are not in operation.
  3. 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 doors need to be opened in order to check connectors, open the doors and leave them open.
  4. Inspect the fuses for circuits related to this system before performing the following inspection procedure.
HINT:
  1. Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.
1.CHECK CAN BUS LINE FOR DISCONNECTION (MAIN BODY ECU BRANCH WIRE)


    Yaris. Ncp93, 131.Networking.Can Communication System (For Sedan).Can Communication System (For Sedan) Main Body Ecu Communication Stop Mode

  1. Turn the ignition switch OFF.

  1. Disconnect the D33 main body ECU connector.

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D33-23 (CANH) - D33-22 (CANL)
    		Ignition switch OFF
    		54 to 69 Ω
    Text in Illustration
    *1
    		Rear view of wire harness connector
    (to Main Body ECU)


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


2.CHECK HARNESS AND CONNECTOR (BECU, IG, GND1)


    Yaris. Ncp93, 131.Networking.Can Communication System (For Sedan).Can Communication System (For Sedan) Main Body Ecu Communication Stop Mode

  1. Disconnect the 4B and 4E main body ECU connectors.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    4E-17 (GND1) - Body ground
    		Always
    		Below 1 Ω

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    4B-30 (BECU) - Body ground
    		Always
    		11 to 14 V
    Text in Illustration
    *1
    		Rear view of wire harness connector
    (to Main Body ECU)

  1. Reconnect the main body ECU connectors.



    Yaris. Ncp93, 131.Networking.Can Communication System (For Sedan).Can Communication System (For Sedan) Main Body Ecu Communication Stop Mode

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    4B-24 (IG) - Body ground
    		Ignition switch ON
    		11 to 14 V
    Text in Illustration
    *1
    		Component with harness connected
    (Main Body ECU)


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE MAIN BODY ECU