Code No. P0171: Abnormal Fuel System (lean)




OPERATION




FUNCTION




TROUBLE JUDGEMENT


Check Conditions
Judgement Criterion
or

Check Conditions
Judgement Criterion
or

Check Conditions
Judgement Criterion
or


FAIL-SAFE AND BACKUP FUNCTION




PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III diagnosis code


Q. Is any other diagnosis code than P0171 stored?

Inspection chart for diagnosis code (Refer to ).
Go to Step 2.

STEP 2. M.U.T.-III data list



  • Data list reference table (Refer to ).

  1. Item 5: Intake air temperature sensor
  2. Item 6: Engine coolant temperature sensor
  3. Item 8: Manifold absolute pressure sensor
  4. Item 10: Air flow sensor
  5. Item BB: Barometric pressure sensor

Q. Are the check results normal?

YES : Go to Step 3.
Perform the diagnosis code classified check procedure for the sensor that has shown an abnormal data value. Inspection chart for diagnosis code (Refer to ).

STEP 3. Check for exhaust leaks


Q. Is the check result normal?

Go to Step 4.
Repair.

STEP 4. Check for intake system vacuum leaks.


Q. Is the check result normal?

Go to Step 5.
Repair.

STEP 5. M.U.T.-III data list



  • Refer to Data List Reference Table .

  1. Item E1: Linear A/F sensor

Q. Are the check results normal?

Go to Step 6.
Check linear A/F sensor system. Check code No.P0131: linear A/F sensor circuit low voltage (Refer to ). Check code No.P0132: linear A/F sensor circuit high voltage (Refer to ).

STEP 6. Check purge control solenoid valve itself.



  • Purge control solenoid valve connector check.
  • Check purge control solenoid valve itself (Refer to GROUP 17- Emission Control <PHEV> - Evaporative Emission Control System - Purge Control Solenoid Valve Check ).

Q. Is the check result normal?

YES : Go to Step 7.
Repair or replace the connector, or replace the purge control solenoid valve.

STEP 7. Check injector itself.



  • No. 1, No. 2, No. 3 and No. 4 injector connector check.
  • Injector check (Refer to ).

Q. Is the check result normal?

Go to Step 8.
Repair or replace the connector, or replace the injector.

STEP 8. Check harness between injector connector and engine-ECU connector.



  1. Check and repair harness between No. 1 injector connector terminal and engine-ECU connector terminal INJ1.
  2. Check and repair harness between No. 2 injector connector terminal and engine-ECU connector terminal INJ2.
  3. Check and repair harness between No. 3 injector connector terminal and engine-ECU connector terminal INJ3.
  4. Check and repair harness between No. 4 injector connector terminal and engine-ECU connector terminal INJ4.

  • Check output line for damage.

Q. Are the check results normal?

Go to Step 9.
Repair or replace the connector, or repair the damaged harness wire.

STEP 9. Fuel pressure measurement.



  • Fuel pressure test (Refer to ).

Q. Is the check result normal?

Go to Step 10.
Repair.

STEP 10. Check fuel.



  • Check for entry of foreign matter (water, diesel fuel, etc.) into fuel.

Q. Is the check result normal?

Go to Step 11.
Replace the fuel.

STEP 11. M.U.T.-III diagnosis code



  • Reconfirmation of diagnosis code.

Q. Is diagnosis code stored?

Replace the engine-ECU.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).