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Diagnostic procedure

DTC P0139 DIAGNOSTIC PROCEDURE

STEP INSPECTION ACTION
1 VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED 
  • Have the FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS (HO2S related) been recorded?
 Yes Go to the next step.
No Record the FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.
2 VERIFY RELATED REPAIR INFORMATION AVAILABILITY 
  • Verify related Service Bulletins and/or-line repair information availability.
  • Is any related repair information available?
 Yes Perform the repair or diagnosis according to the available Service Information.
  • If the vehicle is not repaired, go to the next step.
No Go to the next step.
3 VERIFY RELATED PENDING AND STORED DTC 
  • Turn the ignition switch off, then to the ON position (Engine off).
  • Verify pending and/or stored DTCs using the WDS or equivalent.
  • Is DTC P0443 also present?
 Yes Go to DTC P0443 troubleshooting procedures, then go to Step 13.
No Go to the next step.
4 IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA 
  • Is DTC P0139 on the FREEZE FRAME DATA?
 Yes Go to the next step.
No Go to troubleshooting procedures for the DTC on the FREEZE FRAME DATA.
(See DTC TABLE ).
5 VERIFY CURRENT INPUT SIGNAL STATUS 
  • Warm up the engine.
  • Access the O2S12 PID using the WDS or equivalent.
  • Inspect the PID under the following accelerator pedal conditions or NEUTRAL.
  • Is the PID normal?
    • More than 0.55 V  the accelerator pedal is suddenly depressed (rich condition).
    • Less than 0.55 V  just after accelerator pedal is released (lean condition).
 Yes Go to Step 8.
No Go to the next step.
6 INSPECT INSTALLATION OF REAR HO2S 
  • Inspect if the rear HO2S is loosely installed.
  • Is the sensor installed securely?
 Yes Go to the next step.
No Retighten the sensor, then go to Step 13.
7 INSPECT GAS LEAKAGE FROM EXHAUST SYSTEM 
  • Visually inspect if there is any gas leakage between the exhaust manifold and the rear HO2S.
  • Is there gas leakage?
 Yes Repair or replace the malfunctioning faulty exhaust part, then go to Step 13.
No Replace sensor, then go to Step 13.
8 INSPECT LONG TERM FUEL TRIM 
  • Access the LONG FT1 PI Ds
  • Compare it with the FREEZE FRAME DATA recorded at Step 1.
  • Is it below the FFD value?
 Yes The engine is driven under a rich condition. Go to the next step.
No The engine is driven under a lean condition. Go to Step 10.
9 INSPECT FUEL LINE PRESSURE (Excessive fuel line pressure) 
  • Turn the ignition switch off.
  • Inspect the fuel line pressure while the engine is running.

    (See FUEL LINE PRESSURE INSPECTION ).

  • Is the fuel line pressure normal?
 Yes Go to Step 12.
No Inspect fuel pump maximum pressure and fuel return pipe for clogging.
(See FUEL PUMP UNIT INSPECTION ).
  • If there is any problem, repair or replace the parts.
  • If all items above are normal, replace the fuel pump unit.

Then go to Step 13.
10 INSPECT FUEL LINE PRESSURE (Low fuel line pressure) 
  • Turn the ignition switch off.
  • Inspect the fuel line pressure while the engine is running.

    (See FUEL LINE PRESSURE INSPECTION ).

  • Is the fuel line pressure normal?
 Yes Go to Step 12.
No Go to the next step.
11 INSPECT FUEL LINE FROM FUEL PUMP TO FUEL DELIVERY PIPE 
  • Visually inspect the fuel line for any leakage.
  • Is there fuel leakage?
 Yes Replace the fuel line, then go to Step 13.
No Inspect the fuel filters for the following:
  • Foreign material or staining inside the fuel filter (low-pressure side)

Perform the following actions according to the result.
  • If normal, replace fuel pump unit.

Then go to Step 13.
12 INSPECT SEALING OF ENGINE COOLANT PASSAGE 
 Yes Go to the next step.
No Repair or replace the malfunctioning part according to inspection results.
Then go to the next step.
13 VERIFY TROUBLESHOOTING OF DTC P0139 COMPLETED 
  • Make sure to reconnect all disconnected connectors.
  • Turn the ignition switch to the ON position. (Engine off)
  • Clear the DTC from the memory using the WDS or equivalent.
  • Perform the "PCM Adaptive Memory Produce Drive Mode" and "HO2S heater, HO2S, and TWC Repair Verification Drive Mode".

    (See OBD-II DRIVE MODE ).

  • Is the PENDING CODE for this DTC present?
 Yes Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION ).
No Go to the next step.
14 VERIFY AFTER REPAIR PROCEDURE 
 Yes Go to the applicable DTC troubleshooting.
(See DTC TABLE ).
No Troubleshooting completed.
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