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 is stuck on HI output, the ECM outputs this DTC.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1. CLEAR DTC

(a) Clear the DTC Engine Immobiliser System.

NEXT -- Continue to next step.

2. CHECK FOR DTC

(a) Check for DTC Engine Immobiliser System.

Result





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

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

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

(a) Disconnect the J26 ECU connector.





(b) Disconnect the A24 ECM connector.

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

Standard resistance:





Standard voltage:





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

4. CHECK TRANSPONDER KEY ECU (OUTPUT)

(a) Measure waveform.





Waveform 1 (Reference)





OK:

Waveform is output normally (see illustration).

Result





D -- REPLACE ECM Removal

C -- REPLACE ECM Removal

B -- REPLACE ECM Removal
A -- Continue to next step.

5. CHECK TRANSPONDER KEY ECU (POWER SOURCE AND BODY GROUND)

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





Standard voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE TRANSPONDER KEY ECU Removal