CAN COMMUNICATION SYSTEM Certification ECU Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
Certification ECU Communication Stop Mode

Either condition is met:


  • "Certification (Smart)" is not displayed on the "CAN Bus Check" screen of the GTS Click here

  • Communication system DTCs (DTCs that start with U) that are output correspond to "Certification ECU Communication Stop Mode" in "DTC Combination Table" Click here


  • Certification ECU (Smart Key ECU Assembly) branch line or connector

  • Power source circuit of certification ECU (Smart Key ECU Assembly)

  • Certification ECU (Smart Key ECU Assembly) ground circuit

  • Certification ECU (Smart Key ECU Assembly)

WIRING DIAGRAM

A004JYGE03
A004JYGE04

CAUTION / NOTICE / HINT

Note


  • Before measuring the resistance of the CAN bus, turn the engine switch off and leave the vehicle for 1 minute or more without operating the key, 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 engine 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.

  • 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.

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

  • DTC check procedure: Turn the engine switch on (IG) and wait at least 10 seconds.

  • After the repair, perform CAN Bus Check and check that all the ECUs and sensors connected to the CAN communication system are displayed Click here.

Tech Tips


  • Operating the engine 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 FOR OPEN IN CAN BUS LINES (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) BRANCH LINE)


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

    2. A004JONE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Certification ECU (Smart Key ECU Assembly))

      Disconnect the D41 and D48 certification ECU (smart key ECU assembly) connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D41-14 (CANH) - D41-15 (CANL) Cable disconnected from negative (-) battery terminal 57 to 63 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) ASSEMBLY)

    OK

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. A004JIXE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Certification ECU (Smart Key ECU Assembly))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D48-11 (GND) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω

    2. Connect the cable to the negative (-) battery terminal.

    3. Connect the D41 and D48 certification ECU (smart key ECU assembly) connectors.

      A004J4OE02

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      D41-5 (IG2) - Body ground Engine switch on (IG) 11 to 14 V
      D48-2 (+B) - Body ground Engine switch off 11 to 14 V
      Text in Illustration
      *a

      Component with harness connected

      (Certification ECU (Smart Key ECU Assembly))

    OK

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)