Engine Immobiliser System (w/ Smart Key System)

THEFT DETERRENT / KEYLESS ENTRY: ENGINE IMMOBILISER SYSTEM (w/ Smart Key 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 certification ECU is stuck high output (e.g. shorted to +B), the ECM stores this DTC.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
If the certification ECU is replaced, register the key Engine Immobiliser System (w/ Smart Key System).

PROCEDURE

1. CHECK DTC OUTPUT

(a) Clear the DTCs Engine Immobiliser System (w/ Smart Key System).

(b) Recheck for DTCs Engine Immobiliser System (w/ Smart Key System).

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

Result





B -- GO TO DIAGNOSTIC TROUBLE CODE CHART Engine Immobiliser System (w/ Smart Key System)
A -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - ECM)

(a) Disconnect the certification ECU 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.

3. INSPECT CERTIFICATION ECU

(a) Reconnect the certification ECU connector.

(b) Reconnect the ECM connector.

(c) Using an oscilloscope, check the waveform.





Text in Illustration





Waveform





OK:

Waveform is output normally (See illustration).

NG -- REPLACE ECM Removal
OK -- Continue to next step.

4. REPLACE CERTIFICATION ECU

(a) Replace the certification ECU Removal.

NEXT -- Continue to next step.

5. KEY REGISTRATION

(a) Register the key Engine Immobiliser System (w/ Smart Key System).

NEXT -- Continue to next step.

6. REGISTER ECU COMMUNICATION ID

(a) Register the ECU communication ID Engine Immobiliser System (w/ Smart Key System).

NEXT -- Continue to next step.

7. CHECK DTC OUTPUT

(a) Clear the DTCs Engine Immobiliser System (w/ Smart Key System).

(b) Recheck for DTCs Engine Immobiliser System (w/ Smart Key System).

OK:

DTC B279A is not output.

NG -- REPLACE ECM Removal

OK -- END (CERTIFICATION ECU WAS DEFECTIVE)