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

DTC B279A - Theft Deterrent System Communication Line High Fixation

DESCRIPTION

If the communication line (EFIO - IMI) to the certification ECU (smart key ECU assembly) is stuck high output (e.g. shorted to +B), the ECM stores this DTC.





WIRING DIAGRAM





INSPECTION PROCEDURE
NOTICE: If the certification ECU (smart key ECU assembly) is replaced, register the key Engine Immobiliser System (W/ Smart Key System).

PROCEDURE

1. CHECK DTC OUTPUT
(a) Clear the DTCs Engine Immobilizer System (w/ Smart Key System).
(b) Recheck for DTCs Engine Immobilizer 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
A -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - ECM)
(a) Disconnect the certification ECU (smart 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:

for 2GR-FE





for 1AR-FE





Standard Voltage:





Text in Illustration





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

3. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)
(a) Reconnect the certification ECU (smart key ECU assembly) connector.
(b) Reconnect the ECM connector.
(c) Using an oscilloscope, check the waveform.





Waveform (Reference):





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





Text in Illustration





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

4. REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)
(a) Replace the certification ECU (smart key ECU assembly) 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 Immobilizer System (w/ Smart Key System).
(b) Recheck for DTCs Engine Immobilizer System (w/ Smart Key System).
OK:
DTC B279A is not output.
Result:





C -- REPLACE ECM
B -- REPLACE ECM
A -- END (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) WAS DEFECTIVE)