FUEL SYSTEM ON-VEHICLE INSPECTION

PROCEDURE


  1. CHECK FUEL PRESSURE


    1. Read Data List

      Note

      In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not.

      Tech Tips

      Using the intelligent tester to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the Data List information early in troubleshooting is one way to save diagnostic time.


      1. Warm up the engine.

      2. Turn the ignition switch off.

      3. Connect the intelligent tester to the DLC3.

      4. Turn the ignition switch on (IG).

      5. Turn the intelligent tester on.

      6. Enter the following menus: Powertrain / Engine / Data List.

      7. According to the display on the tester, read the Data List.

        Tester Display Measurement Item/Range Normal Condition
        Fuel Press

        Fuel pressure/

        Min.: 0 kPa, Max.: 250000 kPa

        		 Idling: 30000 to 40000 kPa
        Target Common Rail Pressure

        Target common rail pressure/

        Min.: 0 kPa, Max.: 250000 kPa

        		 25000 to 180000 kPa when engine running

  2. INSPECT FOR FUEL LEAK

    CAUTION:


    • During Active Test mode, engine speed becomes high and combustion noise becomes loud, so pay attention.

    • During Active Test mode, fuel becomes highly pressurized. Be extremely careful not to expose your eyes, hands, or body to escaped fuel.


    1. Check that there are no leaks from any part of the fuel system when the engine is stopped. If there is fuel leakage, repair or replace parts as necessary.

    2. Start the engine and check that there are no leaks from any part of the fuel system. If there is fuel leakage, repair or replace parts as necessary.

    3. Disconnect the return hose from the common rail.

    4. Start the engine and check for fuel leaks from the return pipe.

      If there is fuel leakage, replace the common rail.

    5. Connect the intelligent tester to the DLC3.

    6. Start the engine and turn the intelligent tester on.

    7. Select the Fuel Leak test from the Active Test mode on the intelligent tester.

    8. If the intelligent tester is not available, fully depress the accelerator pedal quickly. Increase the engine speed to the maximum and maintain that speed for 2 seconds. Repeat this operation several times.

    9. Check that there are no leaks from any part of the fuel system.

      Note

      A return pipe leakage of less than 10 cc (0.6 cu in.) per minute is acceptable.

      If there is fuel leakage, repair or replace parts as necessary.

    10. Reconnect the return hose to the common rail.

  3. CHECK PRESSURE DISCHARGE VALVE

    Tech Tips


    • This is the procedure for troubleshooting fuel pressure control malfunctions and combustion problems.

    • Malfunctions can be determined by checking the fuel pressure when performing fuel cut and operating the pressure discharge valve with the intelligent tester.

    • During "Pressure Discharge Valve Check", the intelligent tester measures the fuel pressure while the engine is running, after the engine is stopped, and after the pressure discharge valve operates.


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch on (IG).

    3. B001FRJ

      Turn the intelligent tester on.

      Note

      The following conditions must be met:


      • The engine is idling.

      • The vehicle is stopped.

      • The fuel pressure is not extremely high (e.g. below 100 MPa).

      • The fuel pressure sensor is normal.

      • The battery voltage is higher than 8 V.

    4. Enter the following menus: Powertrain /Engine / Utility / Pressure Discharge Valve Check.

    5. B001DE3

      Press "Next".

    6. B001DPI

      Press "Next" again to proceed.

    7. B001EYQ

      Select "Close to Open Check".

    8. Press "Next".

    9. Read the value of "Open and Engine OFF".

      B001H32
      OK
      0.5 MPa or less

      Tech Tips


      • When the system is normal, the value of "Open and Engine OFF" should be at or close to 0 MPa.

      • When the fuel pressure value of "Open and Engine OFF" does not become equal to or less than 0.5 MPa, the pressure discharge valve may be stuck closed.

      • When the fuel pressure values of "Close and Engine OFF" and "Open and Engine OFF" are both 0 MPa, the pressure discharge valve may be stuck open or there may be a fuel leak.

      • Perform "Always Closed Check" if the value is not 0 MPa when the pressure discharge valve is open during "Close to Open Check". If the results are the same as during "Close to Open Check", there is a pressure discharge valve operation malfunction.

        B001EP6E01
      Text in Illustration
      *1 Fuel Press (Always Closed Check) *2 Fuel Press (Close to Open Check)
      *3 Engine Speed *4 Fuel Cut Operation Signal
      *5 Fuel Pressure Relief Valve Operation Prohibition *6 Fuel Pressure Relief Valve Operation (Always Closed Check)
      *7 Fuel Pressure Relief Valve Operation (Close to Open Check) - -
      *a Fuel Press Recorded Point *b Closed (on)
      *c Open (on) - -
      B001CHY Fuel Pressure Relief Valve Operation Start - -

  4. BLEED AIR FROM FUEL SYSTEM


    1. B001E40

      Using the hand pump mounted on the fuel filter cap, bleed the air from the fuel system. Continue pumping until the pump resistance increases.

      Note


      • The maximum hand pump pumping speed is 2 strokes per second.

      • The hand pump must be pushed with a full stroke during pumping.

      • When the fuel pressure at the supply pump inlet port reaches a saturated pressure, the hand pump resistance increases.

      • If pumping is interrupted during the air bleeding process, fuel in the fuel line may return to the fuel tank. Continue pumping until the hand pump resistance increases.

      • If the hand pump resistance does not increase despite consecutively pumping 200 times or more, there may be a fuel leak between the fuel tank and fuel filter, the hand pump may be malfunctioning, or the vehicle may have run out of fuel.

      • If air bleeding using the hand pump is incomplete, the common rail pressure does not rise to the pressure range necessary for normal use and the engine cannot be started.

    2. Start the engine.

      Note


      • Even if air bleeding using the hand pump has been completed, the starter may need to be cranked for 10 seconds or more to start the engine.

      • Do not crank the engine continuously for more than 20 seconds. The battery may be discharged.

      • Use a fully-charged battery.


      1. When the engine can be started, proceed to the next step.

      2. If the engine cannot be started, bleed the air again using the hand pump until the hand pump resistance increases (refer to the procedures above). Then start the engine.

    3. Turn the ignition switch off.

    4. Connect the intelligent tester to the DLC3.

    5. Turn the ignition switch on (IG) and turn the intelligent tester on.

    6. Clear the DTCs Click here.

    7. Start the engine.*1

    8. B001E01E05
      Text in Illustration
      *a

      Reference

      Active Test Operation

      Enter the following menus: Powertrain / Engine and ECT / Active Test / Test the Fuel Leak.*2

    9. Perform the following test 5 times with on/off intervals of 10 seconds: Active Test / Test the Fuel Leak.*3

    10. Allow the engine to idle for 3 minutes or more after performing the Active Test for the 5th time.

      B001F07E04

      Tech Tips

      When the Active Test "Test the Fuel Leak" is used to change the pump control mode, the actual fuel pressure inside the common rail drops below the target fuel pressure when the Active Test is off, but this is normal and does not indicate a pump malfunction.

    11. Enter the following menus: Powertrain / Engine and ECT / DTC.

    12. Read Current DTCs.

    13. Clear the DTCs Click here.

      Tech Tips

      It is necessary to clear the DTCs as DTC P1604 or P1605 may be stored when air is bled from the fuel system after replacing or repairing fuel system parts.

    14. Repeat steps *1 to *3.

    15. Enter the following menus: Powertrain / Engine and ECT / DTC.

    16. Read Current DTCs.

      OK
      No DTCs are output.

  5. CHECK FUEL FILTER WARNING LIGHT AND DRAIN WATER


    1. Check the fuel filter multi-information display.

      Note

      When the fuel system warning is displayed on the multi-information display, replace the fuel filter Click here or drain the water in the fuel filter.

    2. Drain water.


      1. B001F7Z

        w/ Fuel Heater:

        Disconnect the level warning switch connector and fuel heater connector.

      2. B001FIM

        w/ Clogging Switch:

        Disconnect the level warning switch connector and clogging switch connector.

      3. Remove the 2 nuts and lift up the fuel filter assembly.

      4. B001F0XE01
        Text in Illustration
        *1 Fuel Filter Drain Plug
        *2 Container

        Connect a hose to the fuel filter drain plug. Place the other end of the hose into a container under the fuel filter drain plug.

      5. Loosen the fuel filter drain plug to drain water.

      6. Tighten the fuel filter drain plug by hand.

        Note

        Do not use any tools in this procedure.

      7. Install the fuel filter assembly with the 2 nuts.

        Torque:
        18 N*m  { 184 kgf*cm, 13 ft.*lbf }

      8. w/ Fuel Heater:

        Connect the level warning switch connector and fuel heater connector.

      9. w/ Clogging Switch:

        Connect the level warning switch connector and clogging switch connector.