CAN COMMUNICATION SYSTEM Certification ECU Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
Certification ECU Communication Stop Mode

  • "Entry and Start/Wireless Tuner" is not displayed on the "Communication Bus Check" screen of the intelligent tester.

  • Applies to Certification ECU Communication Stop Mode in DTC Combination Table.

  • Certification ECU branch wire or connector

  • Power source circuit of certification ECU

  • Certification ECU

WIRING DIAGRAM

A003RKSE01
A003U5XE11

INSPECTION PROCEDURE

Note


  • Turn the power switch off before measuring the resistances between CAN main bus wires and between CAN main 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 (CERTIFICATION ECU BRANCH WIRE)


    1. Turn the power switch off.

    2. A003RI9E08
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Certification ECU)

      Disconnect the certification ECU connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      E117-27 (CANH) - E117-28 (CANL) Power switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CERTIFICATION ECU BRANCH WIRE)

    OK

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)


    1. A003RI9E09
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Certification ECU)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      E117-1 (+B) - Body ground Always 11 to 14 V
      E117-18 (IG) - Body ground Power switch on (IG) 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    OK

  3. CHECK HARNESS AND CONNECTOR (GROUND TERMINAL)


    1. A003RI9E10
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Certification ECU)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E117-17 (E) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GROUND CIRCUIT)

    OK

    REPLACE CERTIFICATION ECU