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 "Bus Check".

  • "Certification ECU Communication Stop Mode" in "DTC Combination Table" applies.

  • Power source or inside certification ECU (smart key ECU assembly)

  • Certification ECU (smart key ECU assembly) CAN branch wire or connector

  • Certification ECU (smart key ECU assembly)

WIRING DIAGRAM

A003HE8E02

INSPECTION PROCEDURE

Note


  • Before replacing the certification ECU (smart key ECU assembly), refer to the smart entry and start system Click here.

  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

Tech Tips

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

PROCEDURE


  1. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL


    1. Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and the CAN branch wire.

      CAUTION:

      For vehicles with an airbag system:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected Click here.


    NEXT

  2. CHECK FOR OPEN IN CAN BUS WIRE (CERTIFICATION ECU CAN BRANCH WIRE)


    1. A003E8CE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Certification ECU [Smart Key ECU Assembly])

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

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      B76-40 (CANH) - B76-18 (CANL) Ignition switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CERTIFICATION ECU CAN BRANCH WIRE OR CONNECTOR (CANH, CANL)

    OK

  3. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - BATTERY AND BODY GROUND)


    1. A003EP2E01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Certification ECU [Smart Key ECU Assembly])

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

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected Click here.

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B75-10 (E) - Body ground Always Below 1 Ω

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      B75-1 (+B) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)