Dtc B2799 Engine Immobiliser System Malfunction

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

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CLEAR DTC

CHECK FOR DTC

INSPECT ECM (TERMINAL IMO)

INSPECT ECM (TERMINAL IMI)

REGISTER ECU COMMUNICATION ID

CHECK WHETHER ENGINE STARTS

INSPECT ECM (IMO TERMINAL VOLTAGE)

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

REPLACE TRANSPONDER KEY ECU ASSEMBLY

REGISTER KEY

REGISTER ECU COMMUNICATION ID

CHECK WHETHER ENGINE STARTS

REPLACE ECM

REGISTER ECU COMMUNICATION ID

CHECK WHETHER ENGINE STARTS

DTC B2799 Engine Immobiliser System Malfunction


DESCRIPTION

This DTC is stored when one of the following occurs: 1) the ECM detects errors in its own communications with the transponder key ECU assembly; 2) the ECM detects errors in the communication lines; or 3) the ECU - ECM communication ID between the transponder key ECU assembly and ECM is different and an engine start is attempted. Before troubleshooting for this DTC, make sure no engine immobiliser DTCs are output. If output, troubleshoot the engine immobiliser DTCs first.

DTC Code
DTC Detection Condition
Trouble Area
DTC Output Confirmation Operation
B2799
Either condition is met (1 trip detection logic*):
  1. A malfunction occurs in the communication or communication lines between the ECM and transponder key ECU assembly.
  2. A communication code cannot be verified during communication between the ECM and transponder key ECU assembly.
  1. Harness or connector
  2. Transponder key ECU assembly
  3. ECM
Either condition is met:
  1. Within 10 seconds of an engine start operation being performed (with the shift lever in P and the brake pedal depressed, turn the ignition switch to ON). If there is a malfunction, the engine stops (communication begins within 3 seconds of the engine start operation being performed, and DTCs are stored after 6 seconds).
  2. 10 seconds after the ignition switch is turned to ON after reconnecting the cable to the negative (-) battery terminal (communication begins within 3 seconds of the ignition switch being turned to ON, and DTCs are stored after 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
-

Related Data List and Active Test
DTC Code
Data List and Active Test
B2799
-

WIRING DIAGRAM


Yaris. Ncp93, 131.Theft Deterrent Keyless Entry.Engine Immobiliser System (For Sedan). Dtc B2799 Engine Immobiliser System Malfunction


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. Start the engine.

  1. Wait 10 seconds or more.

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

    HINT:
    Before checking for DTCs, perform the "DTC Output Confirmation Operation" procedure.
    OK:
    DTC B2799 is not output.
    Result
    Result
    		Proceed to
    OK
    		A
    NG (DTC B2799 is output)
    		B
    NG (Other DTCs are output)
    		C


B
Go to step 3

C
GO TO DIAGNOSTIC TROUBLE CODE CHART (YARIS_NCP93 RM000001TCA01TX.html)
A

USE SIMULATION METHOD TO CHECK (YARIS_NCP93 RM00000135202EX.html)

3.INSPECT ECM (TERMINAL IMO)


  1. Using an oscilloscope, check the waveform.


    Yaris. Ncp93, 131.Theft Deterrent Keyless Entry.Engine Immobiliser System (For Sedan). Dtc B2799 Engine Immobiliser System Malfunction


    Text in Illustration
    *a
    		Component with harness connected
    (ECM)
    		*b
    		Waveform
    Measurement Condition
    Item
    		Content
    Tester Connection
    		A72-29 (IMO) - Body ground
    Tool Setting
    		2 V/DIV., 500 ms./DIV.
    Condition
    		Within 3 seconds after starter operates and initial combustion occurs, or within 3 seconds after ignition switch first turned to ON after battery disconnected and reconnected
    OK:
    Waveform is output normally (refer to illustration).
    Result
    Result
    		Proceed to
    Normal waveform
    		A
    Terminal IMO stuck low (2.4 V or less)
    		B
    Terminal IMO stuck high (12 V) or Abnormal waveform
    		C


B
Go to step 7

C
Go to step 13
A


4.INSPECT ECM (TERMINAL IMI)


  1. Using an oscilloscope, check the waveform.


    Yaris. Ncp93, 131.Theft Deterrent Keyless Entry.Engine Immobiliser System (For Sedan). Dtc B2799 Engine Immobiliser System Malfunction


    Text in Illustration
    *a
    		Component with harness connected
    (ECM)
    		*b
    		Waveform
    Measurement Condition
    Item
    		Content
    Tester Connection
    		A72-28 (IMI) - Body ground
    Tool Setting
    		2 V/DIV., 500 ms./DIV.
    Condition
    		Within 3 seconds after starter operates and initial combustion occurs, or within 3 seconds after ignition switch first turned to ON after battery disconnected and reconnected
    OK:
    Waveform is output normally (refer to illustration).
    Result
    Result
    		Proceed to
    Normal waveform
    		A
    Not output waveform or abnormal waveform
    		B


B
Go to step 9
A


5.REGISTER ECU COMMUNICATION ID

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


NEXT


6.CHECK WHETHER ENGINE STARTS

  1. Check that the engine starts with an already registered vehicle key.

    OK:
    Engine starts normally.


NG
Go to step 13
OK

END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE)

7.INSPECT ECM (IMO TERMINAL VOLTAGE)


    Yaris. Ncp93, 131.Theft Deterrent Keyless Entry.Engine Immobiliser System (For Sedan). Dtc B2799 Engine Immobiliser System Malfunction

  1. Disconnect the A72 ECM connector.

  1. Turn the ignition switch to ON.

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

    Result
    Result
    		Proceed to
    Terminal IMO stuck low (2.4 V or less)
    		A
    Terminal IMO stuck high (12 V)
    		B
    Text in Illustration
    *a
    		Front view of wire harness connector
    (to ECM)


B
Go to step 13
A


8.CHECK HARNESS AND CONNECTOR (ECM - TRANSPONDER KEY ECU AND BODY GROUND)

  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
    D139-12 (EFII) - A72-10 (IMO)
    		Always
    		Below 1 Ω
    D139-12 (EFII) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


9.REPLACE TRANSPONDER KEY ECU ASSEMBLY

  1. Replace the transponder key ECU assembly (YARIS_NCP93 RM000004E7M008X.html).


NEXT


10.REGISTER KEY

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


NEXT


11.REGISTER ECU COMMUNICATION ID

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


NEXT


12.CHECK WHETHER ENGINE STARTS

  1. Check that the engine starts with an already registered vehicle key.

    OK:
    Engine starts normally.


NG
REPLACE ECM (YARIS_NCP93 RM000001CN002IX.html)
OK

END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)

13.REPLACE ECM

  1. Temporarily replace the ECM with a new one (YARIS_NCP93 RM000001CN002IX.html).


NEXT


14.REGISTER ECU COMMUNICATION ID

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


NEXT


15.CHECK WHETHER ENGINE STARTS

  1. Check that the engine starts with the key.

    OK:
    Engine starts normally.


NG
REPLACE TRANSPONDER KEY ECU ASSEMBLY (YARIS_NCP93 RM000004E7M008X.html)
OK

END (ECM WAS DEFECTIVE)