INTAKE SYSTEM ON-VEHICLE INSPECTION

PROCEDURE


  1. CHECK INTAKE AIR CONTROL SYSTEM


    1. Check for leakage or clogging between the air cleaner housing and inlet turbocharger sub-assembly and between the outlet turbocharger sub-assembly and cylinder head sub-assembly.

      Condition Operation
      Clogged air cleaner Replace element
      Hoses collapsed or deformed Repair or replace
      Leakage from connections Check each connection and repair
      Cracks in components Check and replace

  2. CHECK EXHAUST SYSTEM


    1. Check for leakage or clogging between the cylinder head sub-assembly and turbocharger sub-assembly inlet and between the turbocharger sub-assembly outlet and exhaust pipe assembly.

      Condition Operation
      Deformed components Repair or replace
      Foreign material in passages Remove
      Leakage from components Repair or replace
      Cracks in components Check and replace

  3. CHECK AIR INDUCTION SYSTEM

    Tech Tips

    The illustration shows the areas that may draw in secondary air, which could lead to idling problems.


    1. Check that the hoses, gaskets, clamps and O-rings are installed correctly.

    2. Check for cracks, etc. in the hoses, gaskets and O-rings.


      • for V-bank Outside Area:

        A01WRNH

      • for V-bank Inside Area:

        A01WSL1E02
        Text in Illustration
        *A w/ EGR System *B w/o EGR System

  4. CHECK BOOST PRESSURE


    1. Connect the GTS to the DLC3.

    2. Start the engine and turn the GTS on.

    3. Warm up the engine.

      Tech Tips

      Be sure to perform the inspection when the engine coolant temperature is between 75 and 90°C (167 and 194°F).

    4. Enter the following menus: Powertrain / Engine / Data List / VN Turbo.

    5. Take a snapshot of the Data List items with the GTS.

      Tech Tips

      The condition of the turbocharger sub-assembly can be determined by fully depressing the accelerator pedal while driving at 15 km/h (9 mph) in 2nd gear to accelerate the vehicle (obey all laws and regulations, and pay attention to driving conditions while driving the vehicle), and then comparing MAP with Target Booster Pressure at an engine speed of 3000 rpm.

    6. Compare MAP with Target Booster Pressure.

      Standard
      MAP is within 35 kPa of Target Booster Pressure when accelerating with accelerator pedal fully depressed.

      Tech Tips


      • The specification above denotes the difference between the absolute pressure values.

      • If the driving inspection using the GTS above cannot be performed (e.g. due to road conditions), perform the following inspection.


      1. Warm up the engine.

        Tech Tips

        Be sure to perform the inspection when the engine coolant temperature is between 75 and 90°C (167 and 194°F).

      2. A01WPGBE05
        Text in Illustration
        *1 No. 1 Gas Filter
        *2 Manifold Absolute Pressure Sensor
        *a 3-Way Connector

        Using a 3-way connector, connect SST (turbocharger pressure gauge) between the manifold absolute pressure sensor and the No. 1 gas filter.

        SST
        09992-00242

      3. Fully apply the parking brake and chock the 4 wheels.

      4. Move the shift lever to P or N, and then fully depress the accelerator pedal. Measure the boost pressure at maximum engine speed (4700 to 4900 rpm).

        Standard pressure (gauge pressure)
        30 to 60 kPa (0.30 to 0.61 kgf/cm2, 4.3 to 8.7 psi)

        If the pressure is lower than the standard, the following problems may be present.


        • The intake system or exhaust system has leakage or blockage.

        • The turbocharger sub-assembly or ECM is malfunctioning.

        • The EGR valve assembly does not close.

        • The diesel throttle body assembly does not open.

        • The vacuum hose connected to the manifold absolute pressure sensor is cracked or disconnected.

        • The mass air flow meter sub-assembly is malfunctioning.

        • An injector assembly is malfunctioning.

        If the pressure is higher than the standard, check the turbocharger sub-assembly and/or boost control components (manifold absolute pressure sensor, vacuum hose, wire harness, etc.).

    7. Chart showing the suspected trouble areas when the pressure is lower than the standard.

      Tech Tips


      • ○: If a problem listed in the leftmost column of the chart exists, or if the part in the leftmost column of the chart has a malfunction, the value of the Data List item in the uppermost row of the chart will meet the conditions shown in the row labeled "Values which represent a malfunction".

      • The values in the chart are applicable when the engine coolant temperature is between 75 and 90°C (167 and 194°F).

      • The values in the chart are for vehicles equipped with a manual transmission. For vehicles with an automatic transmission, use these values as a reference only as they may differ from the actual values.

      • The values in the chart are valid in an area with an absolute atmospheric pressure higher than 95 kPa. (Standard atmospheric pressure is 101 kPa. Atmospheric pressure decreases by 1 kPa for every 100 m increase in altitude, and is also affected by the current weather conditions.)

      • When the altitude increases, atmospheric pressure and MAP decrease.

      Item

      MAP

      (Absolute pressure inside intake manifold)

      MAF

      (Intake air flow rate)

      		 Accel Position Actual Throttle Position (#1, #2) Actual EGR Valve Pos. (#1, #2)

      EGR Close Lrn. Status (#1, #2)

      (EGR valve fully closed position learning status)

      w/o DPF:

      Fuel Press

      w/ DPF:

      Common Rail Pressure

      		 Injection Feedback Val #1 (to #8)

      Values taken from an actual normal vehicle

      *1

      		 - 228 g/sec. 99% or more

      w/o DPF:

      0%

      		 0%

      w/o DPF:

      OK

      		 -

      -3 to +3 mm3/st

      w/ DPF:

      100%

      w/ DPF:

      -

      Values which represent a malfunction

      *1

      		 MAP is below Target Booster Pressure by 35 kPa or more MAF is less than 190 g/sec.

      Accel Position is not fully depressed position

      *2

      		 Actual Throttle Position (#1, #2) is not within 10% of Target Throttle Position (#1, #2)

      Actual EGR Valve Pos. (#1, #2) is more than 10%

      *3

      w/o DPF:

      NG

      (Determined after performing learning)

      		 Fuel Pressure is below Target Common Rail Pressure by 10 MPa or more (Check while condition steady) Outside of above range

      w/ DPF:

      -
      Turbocharger sub-assembly ○ ○ - - - - - -
      EGR valve assembly does not close or has problem with movement ○ ○ - -

      ○

      (Problem with EGR valve movement)

      *4,*5

      ○

      (EGR valve does not close)

      *4,*5

      		 - -
      Problem with diesel throttle movement

      ○

      (Intake airflow decreases)

      		 ○ - ○ - - - -
      Accelerator pedal cannot be fully depressed or problem with accelerator pedal position sensor exists - ○ ○ - - - - -
      Intake air system leakage or blockage ○ ○ - - - - - -
      Exhaust gas leakage before turbocharger sub-assembly or blockage ○ ○ - - - - - -
      Manifold absolute pressure sensor ○ ○ - - - - - -
      Manifold absolute pressure sensor hose is disconnected ○ ○ - - - - - -
      Mass air flow meter sub-assembly - ○ - - - - - -
      Fuel system (injector assembly, supply pump assembly or common rail assembly) ○ ○ - - - -

      ○

      (Injector assembly leakage, decrease in pressure discharge valve relief pressure or valve is stuck)

      ○

      *6

      Tech Tips


      • *1: These values are measured when the transmission is in 2nd gear, the accelerator pedal is fully depressed, the vehicle is accelerating, and the engine speed is 3000 rpm.

      • *2: The Accel Position is the accelerator opening angle (%) for engine control use. The value indicates around 100% when the accelerator pedal is fully depressed. If the value does not indicate around 100% when the accelerator pedal is fully depressed, the accelerator pedal position sensor circuit or the pedal itself is malfunctioning. When the MIL is illuminated, even with the accelerator pedal fully depressed and an Accel Position of below 70%, it means the fail-safe is restricting the accelerator.

      • *3: Check that the Actual EGR Valve Pos. is always following the Target EGR Position value (e.g. the Actual EGR Valve Pos. is around the fully closed position when the Target EGR Position value indicates 0%). The EGR valve assembly may be malfunctioning if the value is stuck or does not fluctuate smoothly. However, in some cases the EGR valve assembly may be malfunctioning even if the Actual EGR Valve Pos. value is normal. Inspect the EGR valve assembly for any defects (deposits, valve stuck, poor movement, etc.) if necessary.

      • *4: w/ DPF

        DTC P0400 (Bank 1, Bank 2) or P042E (for Bank 1) or P045E (for Bank 2) may be stored at this time. If the actual EGR valve position follows the target EGR valve position slowly, a feeling of hesitation may occur.

      • *5: w/o DPF

        DTC P0400 (for Bank 1) or P1248 (for Bank 2) may be stored at this time. If the actual EGR valve position follows the target EGR valve position slowly, a feeling of hesitation may occur.

      • *6: If Injection Feedback Val # of a cylinder is not within -3 to +3 mm3/st, the corresponding cylinder may have a malfunction (injector or compression). However, in some cases the cylinder may be malfunctioning even if the value is within -3 to +3 mm3/st because these values are injection volume correction values calculated by the ECM during engine idling and not correction values for the high engine load condition related to boost pressure control and engine output performance.

  5. CHECK TURBOCHARGER SUB-ASSEMBLY

    CAUTION:


    • Wear protective gloves to prevent injuries and burns when checking the turbocharger sub-assembly.

    • The engine compartment becomes hot when the engine is running.


    1. Make sure that the DC motors connector is properly connected.

    2. A01WUDCE05
      Text in Illustration
      *a Engine switch on (IG)
      *b Engine idling
      *c

      *b → *c → *d:

      Turn the engine switch off at idling
      *d Engine switch off

      Check the motor movement when turning the engine switch on (IG), when starting the engine, and then when turning the engine switch off.

      If the result is not as specified, check the ECM.