Theft Deterrent System Communication Line High Fixation - Smart Key System

DOOR LOCK: 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 ID code box is stuck on HI output, the ECM stores this DTC.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. CHECK DTC OUTPUT
(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(b) Recheck for DTCs.

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 (ID CODE BOX - ECM)

(a) Disconnect the D29 ID code box and A55 ECM connectors.
(b) Measure the resistance according to the value(s) in the table below.
Resistance:

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

3. CHECK ID CODE BOX (WAVEFORM)
(a) Reconnect the D29 ID code box and A55 ECM connectors.

(b) Using an oscilloscope, check the waveform.
Waveform (Reference):

OK:
Normal waveform is output (see illustration).

NG -- REPLACE ID CODE BOX
OK -- REPLACE ECM
4. REPLACE ID CODE BOX
(a) Replace the ID code box Removal.
NEXT -- Continue to next step.

5. ECU CODE REGISTRATION
(a) Register the ECU code Registration.
NEXT -- Continue to next step.

6. REGISTER ECU COMMUNICATION ID
(a) Register the ECU communication ID Registration.
NEXT -- Continue to next step.

7. CHECK DTC OUTPUT
(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(b) Recheck for DTCs.
OK:
DTC B279A is not output.

NG -- REPLACE ECM
OK -- END (ID CODE BOX WAS DEFECTIVE)