CAN COMMUNICATION SYSTEM > Main Body ECU Communication Stop Mode

for Preparation Click here


DESCRIPTION


Detection Item
Symptom
Trouble Area
Main Body ECU Communication Stop Mode
  1. "Main Body" not displayed on "Communication Bus Check" screen of intelligent tester
  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
  4. Instrument panel junction block assembly

WIRING DIAGRAM


E175989E01


INSPECTION PROCEDURE

NOTICE:
  1. Inspect the fuses for circuit related to this system before performing the following inspection procedure.
  2. Turn the ignition switch off before measuring the resistances of the CAN main wire and the CAN branch wire.
  3. After the ignition switch is turned off, check that the key reminder warning system and light reminder warning system are not in operation.
  4. 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.

HINT:
Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

1.CHECK FOR OPEN IN CAN BUS WIRE (MAIN BODY ECU BRANCH WIRE)


    E175990E01

  1. Turn the ignition switch off.

  1. Disconnect the D42 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
    D42-14 (CANH) - D42-13 (CANL)
    		Ignition switch off
    		54 to 69 Ω

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Main Body ECU)

  1. Reconnect the main body ECU connector.



NG
REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (CAN-H, CAN-L)
OK


2.READ VALUE USING INTELLIGENT TESTER (IG SW)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON and turn the intelligent tester on.

  1. Enter the following menus: Body / Main Body / Data List / IG SW (Click here).

  1. Read the value displayed on the intelligent tester.

    Body / Main Body / Data List 
    Item
    		Measurement Item/Range
    (Display)
    		Normal Condition
    		Diagnostic Note
    IG SW
    		Ignition switch / ON or OFF
    		ON: Ignition switch is ON
    OFF: Ignition switch is off
    		-

    OK:
    Ignition switch condition is displayed correctly.



NG
Go to step 3
OK

REPLACE MAIN BODY ECU (Click here)  

3.CHECK HARNESS AND CONNECTOR (JUNCTION BLOCK POWER SOURCE)

B210280E02


Text in Illustration 
*1
Front view of wire harness connector
(to Instrument Panel Junction Block Assembly)

  1. Disconnect the 3C and 3D instrument panel junction block assembly connectors.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    3C-10 (GND1) - Body ground
    		Always
    		Below 1 Ω
    3D-5 (GND2) - Body ground
    		Always
    		Below 1 Ω

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    3C-23 (+S) - Body ground
    		Ignition switch ON
    		11 to 14 V

  1. Reconnect the instrument panel junction block assembly connectors.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.REPLACE MAIN BODY ECU

  1. Replace the main body ECU with a new or normal one (Click here).

    OK:
    The vehicle is returned to its normal condition and operates normally.



NG
REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (Click here)
OK

END