Engine Immobilizer System (w/ Smart Key System)

ENGINE IMMOBILISER: 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 ID code box is stuck on HI output, the ECM outputs this DTC.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CLEAR DTC

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

NEXT -- Continue to next step.

2. CHECK FOR DTC

(a) Check for DTCs Engine Immobilizer System (w/ Smart Key System).

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

Result





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

3. CHECK HARNESS AND CONNECTOR (ID CODE BOX - ECM)





(a) Disconnect the E79 box connector.

(b) Disconnect the A9 ECM connector.

(c) Measure the resistance and voltage according to the value(s) in the table below.

Standard Resistance:

for 2AR-FE
for 2GR-FE










Standard Voltage:

for 2AR-FE
for 2GR-FE










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

4. CHECK ID CODE BOX (OUTPUT)





(a) Using an oscilloscope, check the waveform.

Measurement Condition





OK:

Waveform is output normally (see illustration).

Result





B -- REPLACE ECM Removal

C -- CHECK ID CODE BOX (POWER SOURCE AND BODY GROUND)

A -- REPLACE ECM Removal

5. CHECK ID CODE BOX (POWER SOURCE AND BODY GROUND)





(a) Turn the engine switch on (IG).

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ID CODE BOX Removal