Engine Immobiliser System (w/o Smart Key System)

THEFT DETERRENT / KEYLESS ENTRY: ENGINE IMMOBILISER SYSTEM (w/o Smart Key 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 transponder key ECU assembly is stuck on HI output, the ECM outputs this DTC.

WIRING DIAGRAM

INSPECTION PROCEDURE
NOTICE:
- If the transponder key ECU assembly is replaced, register the key and ECU communication ID Engine Immobiliser System (W/O Smart Key System).
- If the ECM is replaced, register the ECU communication ID Engine Immobiliser System (W/O Smart Key System).

PROCEDURE

1. CHECK DTC OUTPUT
(a) Recheck for DTCs Engine Immobiliser System (w/o Smart Key System).
HINT: If any DTCs other than DTC B279A are output, troubleshoot those DTCs first.

Result:

A -- GO TO DTC CHART
B -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - ECM)
(a) Disconnect the transponder key ECU assembly 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 transponder key ECU assembly connector.
(b) Reconnect the ECM connector.
(c) Measure the waveform.

Waveform 1 (Reference):

Result:

B -- REPLACE ECM
A -- REPLACE ECM
C -- Continue to next step.
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 Engine Immobiliser System (W/O Smart Key System).
NEXT -- Continue to next step.
6. REGISTER ECU COMMUNICATION ID
(a) Register the ECU communication ID Engine Immobiliser System (W/O Smart Key System).
NEXT -- Continue to next step.
7. CHECK DTC OUTPUT
(a) Clear the DTCs Engine Immobiliser System (w/o Smart Key System).
(b) Recheck for DTCs.
OK:
B279A is not reoutput.
Result:

B -- REPLACE ECM
A -- REPLACE ECM
C -- END (TRANSPONDER KEY ECU IS DEFECTIVE)