Engine Immobiliser System (w/o Smart Key System)

ENGINE IMMOBILISER: ENGINE IMMOBILISER SYSTEM (w/o Smart Key System): B279A-186: Engine Immobiliser System Communication Line High Fixation
B279A-186 - Engine Immobiliser System Communication Line High Fixation

DESCRIPTION

If the communication line (EFIO - IMI) to the transponder key ECU assembly is stuck high output (e. g. shorted to +B), the hybrid vehicle control ECU stores this DTC.

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:
* If the transponder key ECU assembly is replaced, register the ECU code and ECU communication ID Engine Immobiliser System (W/ Smart Key System).
* If the hybrid vehicle control ECU is replaced, register the ECU communication ID Engine Immobiliser System (W/ Smart Key System).

PROCEDURE

1. CHECK DTC OUTPUT

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

(b) Recheck for DTCs.

HINT
If any DTCs other than DTC B279A-186 outputs recur, 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 (ID CODE BOX - HYBRID VEHICLE CONTROL ECU)

(a) Disconnect the transponder key ECU assembly and hybrid vehicle control ECU connector.

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

Standard resistance:

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

3. CHECK TRANSPONDER KEY ECU ASSEMBLY (OUTPUT)

(a) Reconnect the transponder key ECU assembly and hybrid vehicle control ECU connector.

(b) Using an oscilloscope, check the waveform.

Waveform (Reference):

OK:

Waveform is output normally (see illustration).

NG -- REPLACE TRANSPONDER KEY ECU ASSEMBLY

OK -- REPLACE HYBRID VEHICLE CONTROL ECU Removal

4. REPLACE TRANSPONDER KEY ECU ASSEMBLY

(a) Replace the transponder key ECU assembly Removal.

NEXT -- Continue to next step.

5. REGISTER ECU COMMUNICATION ID

(a) Re-register the ECU code Engine Immobiliser System (W/ Smart Key System).

NEXT -- Continue to next step.

6. CHECK DTC OUTPUT

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

(b) Recheck for DTCs.

OK:

DTC B279A-186 output does not recur.

NG -- REPLACE HYBRID VEHICLE CONTROL ECU Removal

OK -- END (TRANSPONDER KEY ECU WAS DEFECTIVE)