ECD SYSTEM, Diagnostic DTC:B2799

DTC Code DTC Name
B2799 Communication with Immobiliser

DESCRIPTION

This DTC is output when the ECM detects errors in communication between the transponder key ECU and the ECM.

This DTC is also output when an engine start is attempted while the ECU communication IDs of the transponder key ECU and the ECM are different.

Before troubleshooting for this DTC, make sure that no other DTCs have been detected in the transponder key ECU.

If any DTCs relating to key codes have been detected in the transponder key, troubleshoot those DTCs first.

DTC No. DTC Detection Condition Trouble Area Possible to Detect
Ignition Switch Engine Run
B2799

Any of the following condition (a), (b) or (c) is met:

(a) Error in communication between ECM and transponder key ECU, and in communication line.

(b) Communication IDs of transponder key ECU and ECM are different.

(c) The key is not registered.

  • Wire harness

  • Transponder key ECU

  • ECM

 ON ON

FAIL-SAFE

DTC No. Fail-safe Operation Fail-safe Deactivation Condition
B2799 - -

WIRING DIAGRAM

A0135Y9E02

INSPECTION PROCEDURE

Tech Tips


  • If the ECM is replaced, variant coding (variant coding indicates the presence of vehicle accessory items, A/C, etc.) should always be performed Click here.

  • Before removing the ECM and the peripheral parts, wait at least 3 minute after turning the ignition switch off (If the cooling fan is operating, remove the ECM and the peripheral parts after the fan stops.).

PROCEDURE


  1. CHECK DTC OUTPUT (OTHER THAN B2799)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to the ON position and turn the intelligent tester on.

    3. Select the following menu items: Powertrain / Engine and ECT / DTC.

    4. Read the DTCs.

      Result
      Display (DTC Output) Proceed To
      B2799 A
      B2799 and other DTCs B

      Tech Tips

      If codes other than B2799 are output, perform troubleshooting for those DTCs first.


    B

    GO TO DTC CHART

    A

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


    1. A0138V4E01

      Disconnect the A35 (A36) ECM connector.

    2. Disconnect the C30 transponder key ECU connector.

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

      Standard resistance (Check for open)
      LHD
      Tester Connection Specified Condition
      RXIM (A35-12) - EFIO (C30-13) Below 1 Ω
      TXIM (A35-14) - EFII (C30-12) Below 1 Ω
      RHD
      Tester Connection Specified Condition
      RXIM (A36-12) - EFIO (C30-13) Below 1 Ω
      TXIM (A36-14) - EFII (C30-12) Below 1 Ω
      Standard resistance (Check for short)
      LHD
      Tester Connection Specified Condition
      RXIM (A35-12) or EFIO (C30-13) - Body ground 10 kΩ or higher
      TXIM (A35-14) or EFII (C30-12) - Body ground 10 kΩ or higher
      RHD
      Tester Connection Specified Condition
      RXIM (A36-12) or EFIO (C30-13) - Body ground 10 kΩ or higher
      TXIM (A36-14) or EFII (C30-12) - Body ground 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. REPLACE TRANSPONDER KEY ECU


    NEXT

  4. CHECK IF DTC RECURS (B2799)


    1. Connect the intelligent tester to the DLC3.

    2. Clear the DTC Click here.

    3. Turn the ignition switch to the ON position and turn the intelligent tester on.

    4. Select the following menu items: Powertrain / Engine and ECT / DTC.

    5. Read the DTCs displayed on the intelligent tester.

      Result
      Display (DTC Output) Proceed To
      No output A
      B2799 B

    B

    REPLACE ECM

    A

    END