B279A

ENGINE IMMOBILISER: ENGINE IMMOBILISER SYSTEM: B279A: Theft Deterrent System Communication Line High Fixation
B279A - Theft Deterrent System Communication Line High Fixation

DESCRIPTION

If the communication line (EFIO-IMI) to the transponder key ECU assembly is stuck on HI output, the ECM stores this DTC.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. CHECK DTC OUTPUT

(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(b) Recheck for DTCs.

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

Result:

B -- GO TO DIAGNOSTIC TROUBLE CODE CHART Engine Immobilizer System
A -- Continue to next step.

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

(a) Disconnect the T8 ECU and E5 ECM connectors.

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

Resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

3. CHECK TRANSPONDER KEY ECU ASSEMBLY (WAVEFORM)

(a) Reconnect the T8 ECU and E5 ECM connectors.

(b) Using an oscilloscope, check the waveform.

Waveform (Reference):

OK:

Normal waveform is output (see illustration).

NG -- REPLACE TRANSPONDER KEY ECU ASSEMBLY

OK -- REPLACE ECM Removal

4. REPLACE TRANSPONDER KEY ECU ASSEMBLY

(a) Replace the transponder key ECU assembly Removal.

NEXT -- Continue to next step.

5. REGISTER KEY

(a) Register the key Programming and Relearning.

NEXT -- Continue to next step.

6. REGISTER ECU COMMUNICATION ID

(a) Register the ECU communication ID Programming and Relearning.

NEXT -- Continue to next step.

7. CHECK DTC OUTPUT

(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(b) Recheck for DTCs.

OK:

DTC B279A is not output.

NG -- REPLACE ECM Removal

OK -- END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)