IMMOBILISER SYSTEM(w/o Entry and Start System), Diagnostic DTC:B2799, B279986

DTC Code DTC Name
B2799 Engine Immobiliser System Malfunction
B279986 Engine Immobiliser System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid

DESCRIPTION

The ECM stores this DTC when the communication line between the ECM and transponder key ECU assembly is malfunctioning or the communication ID of the ECM and transponder key ECU assembly do not match.

DTC No. Detection Item DTC Detection Condition Trouble Area Note
B2799 Engine Immobiliser System Malfunction

Either condition is met (1 trip detection logic*2):


  • A malfunction occurs in the communication or communication lines between the ECM and transponder key ECU assembly.

  • A communication code cannot be verified during communication between the ECM and transponder key ECU assembly.

  • Wire harness or connector

  • Transponder key ECU assembly

  • ECM

    DTC Output Confirmation Operation:

  • Start the engine and wait 10 seconds.*1

  • After disconnecting and reconnecting the cable to the negative (-) battery terminal, turn the ignition switch to ON and wait 10 seconds.*2

    *1: Communication starts within 3 seconds of starting the engine. If verification fails, this DTC is stored 6 seconds after communication has completed.

    *2: Communication starts within 3 seconds of turning the ignition switch to ON. If verification fails, this DTC is stored 6 seconds after communication has completed.
B279986 Engine Immobiliser System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid

Either condition is met (1 trip detection logic*2):


  • A malfunction occurs in the communication or communication lines between the ECM and transponder key ECU assembly.

  • A communication code cannot be verified during communication between the ECM and transponder key ECU assembly.

  • Wire harness or connector

  • Transponder key ECU assembly

  • ECM

    DTC Output Confirmation Operation:

  • Start the engine and wait 10 seconds.*1

  • After disconnecting and reconnecting the cable to the negative (-) battery terminal, turn the ignition switch to ON and wait 10 seconds.*2

    *1: Communication starts within 3 seconds of starting the engine. If verification fails, this DTC is stored 6 seconds after communication has completed.

    *2: Communication starts within 3 seconds of turning the ignition switch to ON. If verification fails, this DTC is stored 6 seconds after communication has completed.
DTC Detection Conditions
Vehicle Condition
Pattern 1 Pattern 2
Diagnosis Condition Engine start operation. ○ ○
Malfunction Status A malfunction occurs in the communication or communication lines between the ECM and transponder key ECU assembly. ○ -
A communication code cannot be verified during communication between the ECM and transponder key ECU assembly. - ○
Detection Time - -
Number of Trips 1 trip 1 trip

Tech Tips

DTC will be output when conditions for either of the patterns in the table above are met.

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 No. Data List and Active Test

  • B2799*1

  • B279986*2

 -

*1: for 3ZR-FAE

*2: for 8NR-FTS

WIRING DIAGRAM

A001VP0E11
*1 Transponder Key ECU Assembly

CAUTION / NOTICE / HINT

Note


  • If the transponder key ECU assembly or ECM is replaced, refer to Service Bulletin.

  • After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".

Tech Tips

If transponder key ECU assembly DTCs are output simultaneously, troubleshoot the transponder key ECU assembly DTCs first.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs.


      1. for 8NR-FTS:


        Powertrain > Engine > Clear DTCs

      2. for 3ZR-FAE:


        Powertrain > Engine and ECT > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  2. CHECK FOR DTC


    1. Start the engine.

    2. Check for DTCs.


      1. for 8NR-FTS:


        Powertrain > Engine > Trouble Codes

      2. for 3ZR-FAE:


        Powertrain > Engine and ECT > Trouble Codes

      Tech Tips

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

      OK
      B2799*1 or B279986*2 is not output.
      Result
      Result Proceed to
      OK A
      NG (DTC B2799*1 or B279986*2 is output) B
      NG (Other DTCs are output) C

      *1: for 3ZR-FAE

      *2: for 8NR-FTS


    A

    USE SIMULATION METHOD TO CHECK Click here

    C

    GO TO DIAGNOSTIC TROUBLE CODE CHART

    B

  3. INSPECT ECM (TERMINAL IMO)


    1. Using an oscilloscope, check the waveform

      A001TOWC59
      *a

      Component with harness connected

      (ECM)

      		 *b Waveform
      Measurement Condition
      Item Content
      Tester Connection A38-45 (IMO) - Body ground
      Tool Setting 2 V/DIV., 500 ms./DIV.
      Condition Within 3 seconds of starter operation and initial combustion, or within 3 seconds of ignition switch first being turned to ON after cable disconnected and reconnected to negative (-) battery terminal
      Result
      Result Proceed to
      OK A
      NG (Terminal IMO stuck low (2.4 V or less)) B
      NG (Terminal IMO stuck high (12 V) or abnormal waveform) C

    B

    INSPECT ECM (IMO TERMINAL VOLTAGE) Click here

    C

    GO TO STEP 7 Click here

    A

  4. INSPECT ECM (TERMINAL IMI)


    1. Using an oscilloscope, check the waveform

      A001X5YC32
      *a

      Component with harness connected

      (ECM)

      		 *b Waveform
      Measurement Condition
      Item Content
      Tester Connection A38-28 (IMI) - Body ground
      Tool Setting 2 V/DIV., 500 ms./DIV.
      Condition Ignition switch ON
      OK
      Waveform is similar to that shown in the illustration.
      Result
      Result Proceed to
      OK A
      NG B

    B

    GO TO STEP 12 Click here

    A

  5. REGISTER ECU COMMUNICATION ID


    1. Reregister the ECU communication ID.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  6. CHECK WHETHER ENGINE STARTS


    1. Using a registered key, turn the ignition switch to ON.

    2. Check that the engine starts 5 seconds after the ignition switch was turned to ON.

      OK
      Engine starts normally.
      Result
      Proceed to
      OK
      NG

    OK

    END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE)

    NG

  7. REPLACE ECM


    1. Temporarily replace the ECM with a new one.

      for 3ZR-FAE: Click here

      for 8NR-FTS: Click here

      Result
      Proceed to
      NEXT

    NEXT

  8. REGISTER ECU COMMUNICATION ID


    1. Reregister the ECU communication ID.

      Tech Tips

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  9. CHECK WHETHER ENGINE STARTS


    1. Using a registered key, turn the ignition switch to ON.

    2. Check that the engine starts 5 seconds after the ignition switch was turned to ON.

      OK
      Engine starts normally.
      Result
      Proceed to
      OK
      NG

    OK

    END (ECM WAS DEFECTIVE)

    NG

    REPLACE TRANSPONDER KEY ECU ASSEMBLY

  10. INSPECT ECM (IMO TERMINAL VOLTAGE)


    1. Disconnect the A38 ECM connector

    2. Turn the ignition switch to ON

    3. A001TA6C12
      *a

      Front view of wire harness connector

      (to ECM)

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

      Standard Voltage
      Tester Connection Condition Result
      A38-45 (IMO) - Body ground Ignition switch turned to ON using registered key Terminal IMO stuck low (2.4 V or less)
      Terminal IMO stuck high (12 V) or Abnormal waveform
      Result
      Result Proceed to
      Terminal IMO stuck low (2.4 V or less) A
      Terminal IMO stuck high (12 V) or Abnormal waveform B

    B

    GO TO STEP 7 Click here

    A

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


    1. Disconnect the F22 transponder key ECU assembly connector

    2. Disconnect the A38 ECM connector

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F22-12 (EFII) - A38-45 (IMO) Always Below 1 Ω
      A38-45 (IMO) - Body ground Always 10 kΩ or higher
      F22-12 (EFII) - Body ground Always 10 kΩ or higher
      F22-13 (EFIO) - A38-28 (IMI) Always Below 1 Ω
      A38-28 (IMI) - Body ground Always 10 kΩ or higher
      F22-13 (EFIO) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  12. REPLACE TRANSPONDER KEY ECU ASSEMBLY


    1. Replace the transponder key ECU assembly with a new one.

      Tech Tips

      Refer to Service Bulletin.

      Note

      Key ID code registration is necessary when replacing the transponder key ECU assembly.

      Refer to Service Bulletin.

      Result
      Proceed to
      NEXT

    NEXT

  13. CHECK WHETHER ENGINE STARTS


    1. Using a registered key, turn the ignition switch to ON.

    2. Check that the engine starts 5 seconds after the ignition switch was turned to ON.

      OK
      Engine starts normally.
      Result
      Result Proceed to
      OK A
      NG (for 3ZR-FAE) B
      NG (for 8NR-FTS) C

    A

    END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)

    B

    REPLACE ECM Click here

    C

    REPLACE ECM Click here