Engine Controls - False MIL ON/DTC P0139

VOLUME
3

GROUP
Engine

NUMBER
008

MODEL
Optima

DATE
October 2002

SUBJECT
Optima P0139 Logic

Some 2001 and 2002 model year Optimas equipped with 2.4 liter 4 cylinder engines may experience malfunction indicator light (MIL) illumination with a DTC of P0139, indicating rear oxygen sensor rationality malfunction.

The OBDII system relating to the rationality check of the rear oxygen sensor included thresholds that were too severe for normal operation. Consequently, in certain driving conditions, the system's evaluation of the functionality of the rear oxygen sensor could signal a malfunction of the rear oxygen sensor when a malfunction does not exist. As a result, a false MIL would be set.

To prevent false MIL illumination, the PCM logic related to rear oxygen sensor rationality check was improved from 2003MY production.

For 2001 MY and 2002MY vehicles that experience false MIL, field fix software has been made available to reprogram the PCM.

Use the procedures in this bulletin for reprogramming the PCM.

REPAIR PROCEDURE:





1. Connect the reprogramming adapter to the Hi-Scan Pro as shown.





2. Connect the black Optima 10 pin check connector cable (labeled ECU) to the reprogramming adapter.





3. Remove the program card from the upper slot on the Hi-Scan Pro tool and insert the reprogramming card.





4. Connect the cigar lighter power adapter to the Hi-Scan Pro and connect the reprogramming adapter power supply cable to the cigar lighter power adapter.





5. Connect the cigar lighter power adapter to the vehicle cigar lighter receptacle.

6. Connect the reprogramming adapter cable to the vehicle 10 pin check connector located under the dash next to the OBDII connector.

* NOTICE
Power supply interruptions will prevent proper reprogramming.

Make sure connectors are securely and completely inserted.

7. Turn ignition key to "on".





8. Turn Hi-Scan Pro tool on, select "06. OPTIMA 2.4D REAR 02 SENSOR (P0139)" and press the "ENTER" key.





9. Select "01. OPTIMA2.4D 01/02MY (AUTO MODE)" and press the "ENTER" key.





10. At the prompt, enter your password "0525" and press the "ENTER" key.








Reprogramming will proceed as shown.

* NOTICE
Do not interrupt the reprogramming at any time. The ECM will be rendered inoperative if the program does not download completely.





11. After "REPROGRAMMING COMPLETED" message is received, turn ignition key to the "OFF" position and disconnect Hi-Scan Pro tool from the vehicle. Start engine and verify normal operation.

* NOTICE
If the reprogramming did NOT complete properly or was interrupted, repeat the process using the following procedure.





12. Turn Hi-Scan Pro tool on, select "06. OPTIMA 2.4D REAR 02 SENSOR (P0139)" and press the "ENTER" key.





13. Select "02. OPTIMA 2.4D O1/02MY (ERROR MODE)" and press the "ENTER" key.





14. Choose your vehicle (model year and transmission type) from the sub menu and press the "ENTER" key.





15. At the prompt, enter your password from the table and press the "ENTER" key.











Reprogramming will proceed as shown.





16. After "REPROGRAMMING COMPLETED" message is received, turn ignition key to the "OFF" position and disconnect Hi-Scan Pro tool from the vehicle. Start engine and verify normal operation.

AFFECTED PRODUCTION RANGE:

2001 MY, 2002MY Optima 2.4L 4 Cylinder.





WARRANTY CLAIM INFORMATION: