P0174

P0174 FUEL INJECTION FUNCTION




On Board Diagnosis Logic
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The ECM calculates the necessary compensation to correct the offset between the actual and the theoretical ratios. In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the ECM judges the condition as the fuel injection system malfunction and light up the MIL (2 trip detection logic).

Malfunction is detected when fuel injection system does not operate properly, the amount of mixture ratio compensation is too large. (The mixture ratio is too lean.)

POSSIBLE CAUSE
- Intake air leaks
- Heated oxygen sensor 1
- Injectors
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Mass air flow sensor
- PCV system
(Loose or disconnected rubber tube)

DTC Confirmation Procedure

NOTE: If "DTC Confirmation Procedure" has been previously conducted, always turn ignition switch OFF and wait at least 5 seconds before conducting the next test.

With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 5 seconds.
3. Turn ignition switch ON and select "SELF-LEARN CONTROL" in "WORK SUPPORT" mode with CONSULT-II.




4. Clear the self-learning control coefficient by touching "CLEAR".
5. Select "DATA MONITOR" mode with CONSULT-II.
6. Start engine again and let it idle for at least 10 minutes.
The 1st trip DTC P0171 or P0174 should be detected at this stage, if a malfunction exists. If so, go to "Diagnostic Procedure" below.

7. If it is difficult to start engine at step 6, the fuel injection system has a malfunction, too.
8. Crank engine while depressing accelerator pedal. If engine starts, go to "Diagnostic Procedure" below. If engine does not start, check exhaust and intake air leak visually.

With GST
Follow the procedure "With CONSULT-II".

Wiring Diagram

EC-FUELB1-01:

EC-FUELB2-01:

Diagnostic Procedure

Step 1 - 3:

Step 4 - 5:

Step 6 - 7:

Step 8:

Step 9 - 10: