B279A

THEFT DETERRENT / KEYLESS ENTRY: ENGINE IMMOBILIZER SYSTEM: B279A: Theft Deterrent System Communication Line High Fixation

DTC B279A - Theft Deterrent System Communication Line High Fixation

DESCRIPTION

If the communication line (EFIO-IMI) to the ID code box (immobilizer code ECU) is stuck on HI output, the ECM outputs this DTC.

WIRING DIAGRAM

INSPECTION PROCEDURE
NOTICE:
- If the ID code box (immobilizer code ECU) is replaced, register the ECU code and ECU communication ID Engine Immobilizer System.
- If the ECM is replaced, register the ECU communication ID Engine Immobilizer System.

PROCEDURE

1. CHECK DTC OUTPUT
(a) Clear the DTCs Engine Immobilizer System.
(b) Recheck for DTCs.
HINT: If any DTCs other than DTC B279A are output, troubleshoot those DTCs first.

Result:

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

2. CHECK HARNESS AND CONNECTOR (ID CODE BOX (IMMOBILIZER CODE ECU) - ECM)
(a) Disconnect the ID code box (immobilizer code ECU) connector.
(b) Disconnect the ECM connector.

Standard Voltage:

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

3. CHECK ECM (INPUT)
(a) Reconnect the ID code box (immobilizer code ECU) connector.
(b) Reconnect the ECM connector.
(c) Measure the waveform.

Waveform (Reference):

OK:
Waveform is output normally (see illustration).
NG -- REPLACE ID CODE BOX (IMMOBILIZER CODE ECU)
OK -- REPLACE ECM
4. REPLACE ID CODE BOX (IMMOBILIZER CODE ECU)
(a) Replace the ID code box (immobilizer code ECU) 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 Engine Immobilizer System.
(b) Recheck for DTCs.
OK:
B279A output does not recur.
NG -- REPLACE ECM
OK -- END (ID CODE BOX (IMMOBILIZER CODE ECU) IS DEFECTIVE)