Dtc B279A Theft Deterrent System Communication Line High Fixation


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CLEAR DTC

CHECK FOR DTC

CHECK HARNESS AND CONNECTOR (SFI OR ECD COMMUNICATION LINE)

CHECK TRANSPONDER KEY ECU ASSEMBLY (TERMINAL EFIO)

CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - BATTERY AND BODY GROUND)

REPLACE ECM

REGISTER ECU COMMUNICATION ID

CLEAR DTC

CHECK FOR DTC

DTC B279A Theft Deterrent System Communication Line High Fixation


DESCRIPTION

If the communication line (EFIO-IMI) to the 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 (EFIO-IMI) 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 stop).
Engine cannot be started.

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

WIRING DIAGRAM


Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Engine Immobiliser.Engine Immobiliser System. Dtc B279A Theft Deterrent System Communication Line High Fixation


INSPECTION PROCEDURE

NOTICE:
  1. When replacing the transponder key ECU assembly or ECM, refer to the Service Bulletin.
  2. After performing repairs, perform the operation that fulfills the DTC output confirmation operation, and then confirm that no DTCs are output again.
  3. Inspect the fuses for circuits related to this system before performing the following inspection procedure.
HINT:
After troubleshooting for this DTC, make sure B279A is not present. If present, troubleshoot the blocking system DTCs next.
1.CLEAR DTC

  1. Clear the DTCs (Toyota Fortuner RM000000Z3I008X.html).


NEXT


2.CHECK FOR DTC

  1. Check for DTCs (Toyota Fortuner RM000000Z3I008X.html).

    Result
    Result
    		Proceed to
    No DTC is output
    		A
    DTC B279A and other DTCs are output
    		B
    DTC B279A is output
    		C
    HINT:
    If any DTCs other than B279A are output, troubleshoot those DTCs first.


B
Go to DIAGNOSTIC TROUBLE CODE CHART (Toyota Fortuner RM000000Z33012X.html)

C
Go to step 3
A

USE SIMULATION METHOD TO CHECK (Toyota Fortuner RM0000012Q9013X.html)

3.CHECK HARNESS AND CONNECTOR (SFI OR ECD COMMUNICATION LINE)

  1. Disconnect the T21 transponder key ECU assembly connector.

  1. Disconnect the E5 ECM connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    T21-13 (EFIO) - E5-30 (IMI)
    		Always
    		Below 1 Ω
    T21-13 (EFIO) or E5-30 (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
    T21-13 (EFIO) or E5-30 (IMI) - Body ground
    		Always
    		Below 1 V


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.CHECK TRANSPONDER KEY ECU ASSEMBLY (TERMINAL EFIO)


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Engine Immobiliser.Engine Immobiliser System. Dtc B279A Theft Deterrent System Communication Line High Fixation

  1. Using an oscilloscope, check the waveform.

    Measurement Condition
    Item
    		Content
    Tester Connection
    		T21-13 (EFIO) - T21-16 (GND)
    Tool Setting
    		10V/DIV., 100 ms./DIV.
    Condition
    		Ignition switch ON
    HINT:
    The waveform shown in the illustration is an example for reference only. Noise, chattering, etc. are not shown.
OK:
Waveform is output normally (refer to illustration).
Text in Illustration
*1
Waveform
*a
Component with harness connected
(Transponder Key ECU Assembly)


NG
Go to step 5
OK

REPLACE TRANSPONDER KEY ECU ASSEMBLY

5.CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - BATTERY AND BODY GROUND)


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Engine Immobiliser.Engine Immobiliser System. Dtc B279A Theft Deterrent System Communication Line High Fixation

  1. Disconnect the T21 transponder key ECU assembly connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    T21-16 (GND) - Body ground
    		Always
    		Below 1 Ω

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    T21-1 (+B) - Body ground
    		Always
    		11 to 14 V
Text in Illustration
*a
Front view of wire harness connector
(to Transponder Key ECU Assembly)


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


6.REPLACE ECM

  1. Temporarily replace the ECM with a new one.

    1. for 1KD-FTV: Toyota Fortuner RM0000013Z0004X.html
    2. for 2KD-FTV: Toyota Fortuner RM0000043H100CX.html

NEXT


7.REGISTER ECU COMMUNICATION ID

  1. Register the ECU - ECM communication ID (Refer to the Service Bulletin).


NEXT


8.CLEAR DTC

  1. Clear the DTCs (Toyota Fortuner RM000000Z3I008X.html).


NEXT


9.CHECK FOR DTC

  1. Check for DTCs (Toyota Fortuner RM000000Z3I008X.html).

    OK:
    DTC B279A is not output.


NG
REPLACE TRANSPONDER KEY ECU ASSEMBLY
OK

END (ECM IS DEFECTIVE)