DTC    B279A    Theft Deterrent System Communication Line High Fixation

for Preparation Click here


DESCRIPTION

When the communication line (IMI - EFIO) between the power management control ECU and ID code box (immobiliser code ECU) is stuck high, the power management control ECU stores this DTC.

DTC Code
DTC Detection Condition
Trouble Area
DTC Output Confirmation Operation
B279A
The communication line (IMI - EFIO) between the power management control ECU and ID code box (immobiliser code ECU) is stuck high (1 trip detection logic*).
  1. Wire harness or connector (disconnection or break in wire harness is main cause)
  2. ID code box (immobiliser code ECU)
  3. Power management control ECU
Turn the power switch on (IG) and wait 6 seconds.
  1. *: Only output while a malfunction is present.

Vehicle Condition and Fail-safe Operation when Malfunction Detected 
Vehicle Condition when Malfunction Detected
Fail-safe Operation when Malfunction Detected
Hybrid control system cannot be started
Hybrid control system cannot be started

Related Data List and Active Test 
DTC Code
Data List and Active Test
B279A
-

WIRING DIAGRAM


B235867E20


INSPECTION PROCEDURE

NOTICE:
  1. When replacing the ID code box (immobiliser code ECU), refer to the Service Bulletin.
  2. The fixed 12 V power source voltage in the power management control ECU is output through a resistance from terminal IMI. The ID code box (immobiliser code ECU) grounds or does not ground this power source voltage accordingly.
  3. After performing repair, perform the operation that fulfills the DTC output confirmation operation, and then confirm that no DTCs are output again.

HINT:
When DTC B279A and the certification ECU (smart key ECU assembly) DTC are output simultaneously, first perform troubleshooting for the certification ECU (smart key ECU assembly) DTC.

1.CLEAR DTC

  1. Clear the DTCs (Click here).


NEXT


2.CHECK FOR DTC

  1. Turn the power switch on (IG) and wait 10 seconds.

  1. Check for DTCs (Click here).
    Result 
    Result
    		Proceed to
    DTC B279A is output
    		A
    DTC B279A and other DTCs are output
    		B

    HINT:
    If DTCs other than DTC B279A are output, troubleshoot those DTCs first.



B
GO TO DIAGNOSTIC TROUBLE CODE CHART (Click here)
A


3.CHECK CONNECTION OF CONNECTOR

  1. Turn the power switch off.

  1. Check that the connectors are properly connected to the power management control ECU and ID code box (immobiliser code ECU).

    OK:
    Connectors are properly connected.



NG
CONNECT CONNECTORS PROPERLY
OK


4.CHECK HARNESS AND CONNECTOR (ID CODE BOX - POWER MANAGEMENT CONTROL ECU)

  1. Disconnect the H22 box connector.

  1. Disconnect the H4 ECU connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    H22-6 (EFIO) - H4-21 (IMI)
    		Always
    		Below 1 Ω
    H4-21 (IMI) - Body ground
    		Always
    		10 kΩ or higher

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    H4-21 (IMI) - Body ground
    		Always
    		Below 1 V



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5.REPLACE ID CODE BOX (IMMOBILISER CODE ECU)

  1. Replace the ID code box (immobiliser code ECU) with a new one.


NEXT


6.CLEAR DTC

  1. Clear the DTCs (Click here).


NEXT


7.REGISTER RECOGNITION CODES

  1. Register the recognition codes in the ECUs.


NEXT


8.REGISTER ECU COMMUNICATION ID (ID CODE BOX - POWER MANAGEMENT CONTROL ECU)

  1. Register the ECU communication ID.


NEXT


9.CHECK FOR DTC

  1. Check for DTCs (Click here).

    HINT:
    Before checking for DTCs, perform the "DTC Output Confirmation Operation" procedure.

    OK:
    DTC B279A is not output.



NG
REPLACE POWER MANAGEMENT CONTROL ECU (Click here)
OK

END (ID CODE BOX (IMMOBILISER CODE ECU) WAS DEFECTIVE)