B279A
ENGINE IMMOBILISER: ENGINE IMMOBILISER 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 high output (e.g. shorted to +B), the ECM stores this DTC.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
* If the transponder key ECU assembly is replaced, register the key and ECU communication ID Programming and Relearning.
* If the ECM is replaced, register the ECU communication ID Programming and Relearning.
PROCEDURE
1. CHECK DTC OUTPUT
(a) Recheck for DTCs Reading and Clearing Diagnostic Trouble Codes.
HINT
If any DTCs other than DTC B279A are output, troubleshoot those DTCs first.
Result
B -- GO TO DTC CHART Engine Immobilizer System
A -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU ASSEMBLY - ECM)
(a) Disconnect the F54 transponder key ECU assembly connector.
(b) Disconnect the A21 ECM connector.
(c) Measure the resistance and voltage according to the value(s) in the table below.
Standard Resistance:
Standard Voltage:
(d) Reconnect the ECM connector.
(e) Reconnect the transponder key ECU assembly connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. INSPECT TRANSPONDER KEY ECU ASSEMBLY (OUTPUT)
(a) Using an oscilloscope, check the waveform.
Waveform 1
OK:
Waveform is output normally (See illustration)
Text in Illustration
NG -- REPLACE TRANSPONDER KEY ECU ASSEMBLY
OK -- REPLACE ECM Removal
4. REPLACE TRANSPONDER KEY ECU ASSEMBLY
(a) Replace the transponder key ECU assembly Removal.
NEXT -- Continue to next step.
5. REGISTER KEY
(a) Register the key Programming and Relearning.
NEXT -- Continue to next step.
6. REGISTER ECU COMMUNICATION ID
(a) Register the ECU communication ID Programming and Relearning.
NEXT -- Continue to next step.
7. CHECK DTC OUTPUT
(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(b) Recheck for DTCs Reading and Clearing Diagnostic Trouble Codes.
OK:
DTC B279A is not output.
NG -- REPLACE ECM Removal
OK -- END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)