ENGINE IMMOBILISER SYSTEM, Diagnostic DTC:B279A-186

DTC Code DTC Name
B279A-186 Engine Immobiliser System Communication Line High Fixation

DESCRIPTION

If the communication line (EFIO-IMI) to the ID code box is stuck on HI output, the hybrid vehicle control ECU outputs this DTC.

DTC Code DTC Detection Condition Trouble Area
B279A-186 When communication line (EFIO-IMI) between hybrid vehicle control ECU and the ID code box is stuck on HI output

  • Harness or connector

  • ID code box

  • Hybrid vehicle control ECU

WIRING DIAGRAM

A01GXZ4E03

INSPECTION PROCEDURE

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTC Click here.


    NEXT

  2. CHECK FOR DTC


    1. Check for DTC Click here.

      Tech Tips

      If any DTCs other than DTC B279A-186 are output, troubleshoot those DTCs first.

      Result:
      Result Proceed to
      DTC B279A-186 is output A
      DTC B279A-186 and other DTCs are output B

    B

    Go to DIAGNOSTIC TROUBLE CODE CHART Click here

    A

  3. CHECK HARNESS AND CONNECTOR (ID CODE BOX - HYBRID VEHICLE CONTROL ECU)

    A01H21ME03

    1. Disconnect the L32 box connector.

    2. Disconnect the A77 ECU connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      L32-6 (EFIO) - A77-32 (IMI) Always Below 1 Ω
      L32-6 (EFIO) or A77-32 (IMI) - Body ground Always 10 kΩ or higher
      Standard voltage
      Tester Connection Condition Specified Condition
      L32-6 (EFIO) - Body ground Always Below 1 V
      A77-32 (IMI) - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HYBRID VEHICLE CONTROL ECU (INPUT)


    1. Using an oscilloscope, check the waveform.

      A01GYC3E02
      Waveform 1 (Reference):
      Item Content
      Terminal No. (Symbols) A77-32 (IMI) - A77-7 (E1)
      Tool Setting 10 V/DIV., 100 msec./DIV.
      Condition Power switch ON (IG)
      OK
      Waveform is output normally (see illustration).

    NG

    CHECK ID CODE BOX (POWER SOURCE AND BODY GROUND) Click here

    OK

    REPLACE ID CODE BOX

  5. CHECK ID CODE BOX (POWER SOURCE AND BODY GROUND)

    A01GWB8E02

    1. Turn the power switch ON (IG).

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

      Standard voltage
      Tester Connection Condition Specified Condition
      L32-1 (+B) - L32-8 (GND) Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE HYBRID VEHICLE CONTROL ECU Click here