CAN COMMUNICATION SYSTEM(w/o Toyota Safety Sense) 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 "Communication 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


  • Smart key ECU assembly (Certification ECU) branch line or connector

  • Power source circuit of smart key ECU assembly (certification ECU)

  • Smart key ECU assembly (Certification ECU) ground circuit

  • Smart key ECU assembly (Certification ECU)

WIRING DIAGRAM

A01UZ3SE13
A01V03ZE08

CAUTION / NOTICE / HINT

Note


  • Before measuring the resistance of the CAN bus, turn the ignition 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 (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary 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 ignition switch to ON (IG), turn the cruise control system on using the cruise control main switch (ON/OFF switch), wait at least 60 seconds, and then drive the vehicle at a speed of 20 km/h (12 mph) or more.

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

Tech Tips


  • Operating the ignition 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 (SMART KEY ECU ASSEMBLY (CERTIFICATION ECU) BRANCH LINE)


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

    2. A01UY5XE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Smart Key ECU Assembly (Certification ECU))

      Disconnect the smart key ECU assembly (certification ECU) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F47-1 (CANH) - F47-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω

    NG

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

    OK

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. A01UZBBE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Smart Key ECU Assembly (Certification ECU))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F48-1 (E) - Body ground Cable disconnected from negative (-) auxiliary battery terminal Below 1 Ω

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

    3. A01UZ7CE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Smart Key ECU Assembly (Certification ECU))

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      F47-5 (+B) - Body ground Ignition switch off 11 to 14 V
      F47-16 (IG) - Body ground Ignition switch ON (IG) 11 to 14 V

    OK

    REPLACE SMART KEY ECU ASSEMBLY (CERTIFICATION ECU)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)