Engine Immobilizer 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
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 stores this DTC.

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:
* When the transponder key ECU assembly and/or ECM is replaced, refer to Registration Engine Immobilizer System (w/o Smart Key System).
* Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1. CLEAR DTC

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

NEXT -- Continue to next step.

2. CHECK FOR DTC

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

Result

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

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

3. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - ECM)

(a) Disconnect the F34 ECU connector.

(b) Disconnect the F50 ECM connector.

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

Standard Resistance:

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

Standard Voltage:

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

4. CHECK TRANSPONDER KEY ECU ASSEMBLY (OUTPUT)

(a) Using an oscilloscope, check the waveform.

Text in Illustration

Measurement Condition

OK:

Waveform is output normally (refer to illustration).

NG -- CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - BATTERY AND BODY GROUND)

OK -- REPLACE ECM Removal

5. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - BATTERY AND BODY GROUND)

(a) Disconnect the F34 ECU connector.

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

Standard Voltage:

Text in Illustration

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

6. REPLACE TRANSPONDER KEY ECU ASSEMBLY

(a) Replace the transponder key ECU assembly Removal.

NEXT -- Continue to next step.

7. REGISTER ECU - ECM COMMUNICATION ID

(a) Register the ECU - ECM communication ID Engine Immobilizer System (w/o Smart Key System).

NEXT -- Continue to next step.

8. CLEAR DTC

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

NEXT -- Continue to next step.

9. CHECK FOR DTC

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

OK:

DTC B279A is not output.

NG -- REPLACE ECM Removal

OK -- END (TRANSPONDER KEY ECU IS DEFECTIVE)