Dtc B279A Theft Deterrent System Communication Line High Fixation

Vehicle Interior. Yaris. Ncp93, 131
Theft Deterrent Keyless Entry. Yaris. Ncp93, 131

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CLEAR DTC

CHECK FOR DTC

CHECK CONNECTION OF CONNECTOR

CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU ASSEMBLY - ECM)

REPLACE TRANSPONDER KEY ECU ASSEMBLY

REGISTER KEY

REGISTER ECU COMMUNICATION ID

CHECK WHETHER ENGINE STARTS

DTC B279A Theft Deterrent System Communication Line High Fixation


DESCRIPTION

When the communication line (IMI - EFIO) between the ECM and transponder key ECU assembly is stuck on HI output, the ECM stores this DTC.

DTC Code
DTC Detection Condition
Trouble Area
DTC Output Confirmation Operation
B279A
The communication line (IMI - EFIO) between the ECM and transponder key ECU assembly is stuck on HI output (1 trip detection logic*).
  1. Harness or connector
  2. Transponder key ECU assembly
  3. ECM
Turn the ignition switch to ON 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
Engine cannot be started (initial ignition occurs and engine cranks, then ignition stops)
Engine cannot be started

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

WIRING DIAGRAM


Yaris. Ncp93, 131.Theft Deterrent Keyless Entry.Engine Immobiliser System (For Sedan). Dtc B279A Theft Deterrent System Communication Line High Fixation


INSPECTION PROCEDURE

NOTICE:
  1. When replacing the transponder key ECU assembly, refer to the Registration (YARIS_NCP93 RM00000120Y021X.html).
  2. When replacing the ECM, refer to the INITIALIZATION (YARIS_NCP93 RM00000482M008X.html).
  3. After performing repairs, perform the operation that fulfills the DTC output confirmation operation, and then confirm that no DTCs are output again.
1.CLEAR DTC

  1. Clear the DTCs (YARIS_NCP93 RM000001TCQ01OX.html).


NEXT


2.CHECK FOR DTC

  1. Check for DTCs (YARIS_NCP93 RM000001TCQ01OX.html).

    HINT:
    Before checking for DTCs, perform the "DTC Output Confirmation Operation" procedure.
    OK:
    DTC B279A is not output.


NG
Go to step 3
OK

USE SIMULATION METHOD TO CHECK (YARIS_NCP93 RM00000135202EX.html)

3.CHECK CONNECTION OF CONNECTOR

  1. Check that the connectors are properly connected to the ECM and transponder key amplifier assembly.

    OK:
    Connectors are properly connected.


NG
CONNECT CONNECTORS PROPERLY
OK


4.CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU ASSEMBLY - ECM)

  1. Disconnect the D139 transponder key ECU assembly connector.

  1. Disconnect the A72 ECM connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    D139-13 (EFIO) - A72-28 (IMI)
    		Always
    		Below 1 Ω
    D139-13 (EFIO) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5.REPLACE TRANSPONDER KEY ECU ASSEMBLY

  1. Replace the transponder key ECU assembly with a new one (YARIS_NCP93 RM000004E7M008X.html).


NEXT


6.REGISTER KEY

  1. Register the key (YARIS_NCP93 RM00000120Y021X.html).


NEXT


7.REGISTER ECU COMMUNICATION ID

  1. Register the ECU communication ID (YARIS_NCP93 RM00000120Y021X.html).


NEXT


8.CHECK WHETHER ENGINE STARTS

  1. Check that the engine starts with the key.

    OK:
    Engine starts normally.


NG
REPLACE ECM (YARIS_NCP93 RM000001CN002IX.html)
OK

END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)