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 ID code box 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 (ID CODE BOX - ECM)

(a) Disconnect the J69 ID code box and A6 ECM connectors.

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

Standard resistance:

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

3. CHECK ECM (INPUT)

(a) Reconnect the J69 ID code box and A6 ECM connectors.

(b) Using an oscilloscope, check the waveform.

Waveform (Reference):

OK:

Normal waveform is output (see illustration).

Result:

B -- REPLACE ECM Removal

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

4. REPLACE ID CODE BOX

(a) Replace the ID code box Removal.

NEXT -- Continue to next step.

5. REGISTER ECU CODE

(a) Register the ECU code Engine Immobilizer System.

NEXT -- Continue to next step.

6. REGISTER ECU COMMUNICATION ID

(a) Register the ECU communication ID Engine Immobilizer System.

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.

Result:

B -- REPLACE ECM Removal

C -- REPLACE ECM Removal

A -- END (ID CODE BOX WAS DEFECTIVE)