CAN COMMUNICATION SYSTEM ECM Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
ECM Communication Stop Mode

  • "Engine" is not displayed on "Communication Bus Check" screen of the intelligent tester.

  • Applies to ECM Communication Stop Mode in DTC Combination Table.

  • Power source circuit of ECM

  • ECM main wire or connector

  • ECM

WIRING DIAGRAM

A01NERHE01
A01NH6CE01

INSPECTION PROCEDURE

Note


  • Turn the power switch off before measuring the resistances between CAN bus main wires and between CAN bus branch wires.

  • Turn the power switch off before inspecting CAN bus wires for a ground short.

  • After the power switch is turned off, check that the key reminder warning system and light reminder warning system are not operating.

  • Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the power switch, any other switches or the doors. If any doors need to be opened in order to check connectors, open the doors and leave them open.

Tech Tips


  • Operating the power switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.

  • Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE


  1. CHECK CAN BUS WIRE FOR DISCONNECTION (ECM MAIN WIRE)


    1. Turn the power switch off.

    2. A01NEJ1E07
      Text in Illustration
      *1

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      A76-12 (CANH) - A76-25 (CANL) Power switch off 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (ECM MAIN WIRE)

    OK

  2. CHECK ECM POWER SOURCE CIRCUIT


    1. Check the ECM power source circuit Click here.

      Tech Tips

      If there is no abnormality in the ECM power source circuit, replace the ECM.


    NG

    REPAIR OR REPLACE ECM POWER SOURCE CIRCUIT

    OK

    REPLACE ECM Click here