CAN COMMUNICATION SYSTEM ECM Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
ECM Communication Stop Mode

  • "Engine" are not displayed on the "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 line or connector

  • ECM

WIRING DIAGRAM

A003ZQZE02

INSPECTION PROCEDURE

Note


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

  • Turn the power switch off before inspecting CAN bus lines 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 LINE FOR DISCONNECTION (ECM MAIN LINE)


    1. Turn the power switch off.

    2. A003W8AE58
      Text in Illustration
      *a

      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
      A60-13 (CANH) - A60-5 (CANL) Power switch off 108 to 132 Ω

    NG

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

    OK

  2. CHECK ECM POWER SOURCE CIRCUIT


    1. Check the ECM power source circuit.


      Result
      Result Proceed to
      OK (for 2ZR-FXE) A
      OK (for 5ZR-FXE) B
      NG C

    B

    REPLACE ECM Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    A

    REPLACE ECM Click here