B279A

THEFT DETERRENT / KEYLESS ENTRY: ENGINE IMMOBILISER 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 is stuck on HI output, the ECM outputs this DTC.

B279A:

WIRING DIAGRAM





INSPECTION PROCEDURE
NOTICE:
- If the transponder key ECU assembly is replaced, register the key and ECU communication ID Engine Immobiliser System.
- If the ECM is replaced, register the ECU communication ID Engine Immobiliser System.

PROCEDURE

1. CLEAR DTC
(a) Clear the DTCs Engine Immobiliser System.
NEXT -- Continue to next step.

2. CHECK DTC OUTPUT
(a) Recheck for DTCs Engine Immobiliser System.
HINT: If any DTCs other than DTC B279A are output, troubleshoot those DTCs first.

Result:

B279A:

A -- GO TO DTC CHART
B -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - ECM)
(a) Disconnect the transponder key ECU assembly connector.
(b) Disconnect the 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. INSPECT TRANSPONDER KEY ECU ASSEMBLY (OUTPUT)
(a) Reconnect the transponder key ECU assembly connector.
(b) Reconnect the ECM connector.
(c) Measure the waveform.





(1) Measure the waveform.

Waveform 1 (Reference)





OK:
Waveform is output normally (see illustration).
Result:






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

5. REPLACE TRANSPONDER KEY ECU ASSEMBLY
(a) Replace the transponder key ECU assembly Removal.
NEXT -- Continue to next step.

6. KEY REGISTRATION
(a) Register the key Engine Immobiliser System.
NEXT -- Continue to next step.

7. ECU COMMUNICATION ID REGISTRATION
(a) Register the ECU communication ID Engine Immobiliser System
NEXT -- Continue to next step.

8. CHECK DTC OUTPUT
(a) Clear the DTCs Engine Immobiliser System.
(b) Recheck for DTCs.
OK:
B279A output does not reoccur.
Result:






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