ENGINE IMMOBILISER SYSTEM (w/o Smart Entry and Start System), Diagnostic DTC:B279A

DESCRIPTION

If the communication line (EFIO-IMI) to the transponder key ECU assembly is stuck high (e.g. shorted to +B), the ECM stores this DTC.

INSPECTION PROCEDURE

PROCEDURE

1. Click here

   CHECK DTC OUTPUT

   
   

   1. Recheck for DTCs (Click here).

      Tip:

      If any DTCs other than DTC B279A are output, troubleshoot those DTCs first.

      Result
      Result Proceed to DTC B279A is output A DTC B279A and other DTCs are output B

   
   
   • AClick here
   • BClick here
2. Click here

   CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - ECM)

   
   

   1. Disconnect the transponder key ECU assembly connector.

   2. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition D37-13 (EFIO) - D55-14 (IMI) Always Below 1 Ω D37-13 (EFIO) - Body ground Always 10 kΩ or higher

      Standard Voltage
      Tester Connection Condition Specified Condition D37-13 (EFIO) - Body ground Always Below 1 V

   
   
   • OKClick here
   • NGClick here
3. Click here

   CHECK TRANSPONDER KEY ECU ASSEMBLY (OUTPUT)

   
   

   1. Reconnect the transponder key ECU assembly connector.

   2. Reconnect the ECM connector.

   3. 

      Using an oscilloscope, check the waveform.

      Waveform 1 (Reference)
      Item Content Terminal No. (Symbol) D37-13 (EFIO) - D37-16 (GND) Tool Setting 2 V/DIV., 1 sec./DIV. Condition Ignition switch ON

      OK
      Waveform is output normally (see illustration).

      Table 1. Text in Illustration

      *1	Component with harness connected (Transponder Key ECU Assembly)
      *2	GND
      *3	HIGH
      *4	LOW

   
   
   • OKClick here
   • NGClick here
4. Click here

   REPLACE TRANSPONDER KEY ECU ASSEMBLY

   
   

   1. Replace the transponder key ECU assembly.

   
   
   • NEXTClick here
5. Click here

   REGISTER KEY

   
   

   1. Register the key.

   
   
   • NEXTClick here
6. Click here

   REGISTER ECU COMMUNICATION ID

   
   

   1. Register the ECU communication ID.

   
   
   • NEXTClick here
7. Click here

   CHECK DTC OUTPUT

   
   

   1. Clear the DTCs (Click here).

   2. Recheck for DTCs.

      OK
      DTC B279A is not output.

   
   
   • OKClick here
   • NGClick here
8. Click here

   GO TO DTC CHARTClick here

9. Click here

   REPAIR OR REPLACE HARNESS OR CONNECTOR

10. Click here

    END (TRANSPONDER KEY ECU WAS DEFECTIVE)

11. Click here

    REPLACE ECMClick here