Dtc B2791 Communication Condition Failure Between Ecm

Securities. Lexus Is250, Is220D. Gse20 Ale20
Engine Immobiliser. Lexus Is250, Is220D. Gse20 Ale20

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK DTC OUTPUT

ECU COMMUNICATION ID REGISTRATION

CHECK HARNESS AND CONNECTOR (ID CODE BOX - ECM)

REPLACE ID CODE BOX

KEY REGISTRATION

ECU COMMUNICATION ID REGISTRATION

CHECK DTC OUTPUT

DTC B2791 Communication Condition Failure between ECM


DESCRIPTION

This DTC is output when the ID code box dose not respond to a verification request signal from the ECM.
HINT:
If the engine switch is turned off immediately after an engine start, this DTC is also detected.

DTC No.
DTC Detection Condition
Trouble Area
B2791
ID code box dose not respond to a verification request signal from ECM
  1. Wire harness
  2. ID code box
  3. ECM

WIRING DIAGRAM


Lexus Is250, Is220D. Gse20 Ale20.Engine Immobiliser.Engine Immobiliser System (For 2Ad-Fhv). Dtc B2791 Communication Condition Failure Between Ecm


INSPECTION PROCEDURE

1.CHECK DTC OUTPUT

  1. Delete the DTC (Click here).

  1. Recheck for DTC (Click here).

    Result:
    Result
    		Proceed to
    B2791 is output
    		A
    No DTC is output
    		B


B
USE SIMULATION METHOD TO CHECK
A


2.ECU COMMUNICATION ID REGISTRATION

  1. Register the ECU communication ID between the ID code box and ECM.

  1. Recheck for DTC (Click here).

    Result:
    Result
    		Proceed to
    B2791 is output
    		A
    No DTC is output
    		B


B
END
A


3.CHECK HARNESS AND CONNECTOR (ID CODE BOX - ECM)


    Lexus Is250, Is220D. Gse20 Ale20.Engine Immobiliser.Engine Immobiliser System (For 2Ad-Fhv). Dtc B2791 Communication Condition Failure Between Ecm

  1. Disconnect the J69 ECU and A49 ECM connectors.

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

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    J69-6 (EFIO) - A49-16 (IMI)
    		Always
    		Below 1 Ω
    J69-6 (EFIO) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.REPLACE ID CODE BOX

  1. Replace the ID code box.


NEXT


5.KEY REGISTRATION

  1. Register the electrical key code in the certification ECU.


NEXT


6.ECU COMMUNICATION ID REGISTRATION

  1. Register the ECU communication ID between the ID code box and ECM.


NEXT


7.CHECK DTC OUTPUT

  1. Delete the DTC (Click here).

  1. Recheck for DTC (Click here).

    Result:
    Result
    		Proceed to
    B2791 is output
    		A
    No DTC is output
    		B


A
REPLACE ECM
B

END