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Home >> Lexus >> 2019 >> NX 300 Base, AWD >> Repair and Diagnosis >> Engine Mechanical >> Mechanical >> Engine Mechanical - Service Information (1 Of 2) >> Engine >> On-Vehicle Inspection [10/2014 - 05/2019] >> Procedure

On-Vehicle Inspection [10/2014 - 05/2019]: Procedure

  1. INSPECT ENGINE COOLANT 

    Refer to ON-VEHICLE INSPECTION [10/2014 - ]

  2. INSPECT ENGINE OIL 

    Refer to ON-VEHICLE INSPECTION [10/2014 - ]

  3. INSPECT BATTERY 

    Refer to ON-VEHICLE INSPECTION [10/2014 - ]

  4. INSPECT AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY 
    1. Remove the air cleaner filter element sub-assembly.
    2. Visually check that the air cleaner filter element sub-assembly is not excessively damaged or oily.
      NOTE:
      • If there is any dirt or clogs in the air cleaner filter element sub-assembly, clean it with compressed air.
      • If any dirt or clogs remain even after cleaning the air cleaner filter element sub-assembly with compressed air, replace it.
      • If necessary, replace the air cleaner filter element sub-assembly.
    3. Install the air cleaner filter element sub-assembly.
  5. INSPECT SPARK PLUG 

    Refer to PROCEDURE - Step 3 [10/2014 - ]

  6. INSPECT FAN AND GENERATOR V BELT 

    See step  1

  7. INSPECT VALVE LASH ADJUSTER ASSEMBLY 
    1. Rev up the engine several times. Check that the engine does not emit unusual noises.
    2. If unusual noises occur, warm up the engine and idle it for 30 minutes or more, then perform the preceding inspection.

      HINT: 

      If any defects or problems are found during the preceding inspection, perform valve lash adjuster assembly inspection.

      Refer to PROCEDURE - Step 2 [10/2014 - ]

  8. INSPECT IGNITION TIMING 
    1. Warm up and stop the engine.
    2. When using the Techstream:
      1. Connect the Techstream to the DLC3.
      2. Turn the Techstream on.
      3. Start the engine and idle it.
      4. Enter the following menus: Powertrain / Engine / Data List / Ignition Timing Cylinder #1.

        Powertrain > Engine > Data List 

        Tester Display
        Ignition Timing Cylinder #1

        Standard ignition timing

        5 to 20° BTDC @ idle

        NOTE:
        • Turn all the electrical systems and the A/C off.
        • Check the ignition timing with the cooling fan off.
        • When checking the ignition timing, the shift lever should be in N or P.

        HINT: 

        Refer to the Techstream operator's manual for further details.

        If the ignition timing is not as specified, check the valve timing.

      5. Enter the following menus: Powertrain / Engine / Active Test / Activate the TC Terminal / ON.

        Powertrain > Engine > Active Test 

        Tester Display
        Activate the TC Terminal
      6. Monitor Ignition Timing Cylinder #1 of the Data List.

        Standard ignition timing

        8 to 12° BTDC @ idle

        NOTE:
        • Turn all the electrical systems and the A/C off.
        • Check the ignition timing with the cooling fan off.
        • When checking the ignition timing, the shift lever should be in N or P.
      7. Enter the following menus: Activate the TC Terminal / OFF.
      8. Check that the ignition timing advances immediately when the engine speed is increased.
      9. Turn the ignition switch off.
      10. Disconnect the Techstream from the DLC3.
    3. When not using the Techstream:
      1. Remove the No. 1 engine cover sub-assembly.
      2. Connect the tester probe of a timing light to the wire of the ignition coil connector for the No. 1 cylinder.
        NOTE:

        Use a timing light that detects primary signals.

      3. Using SST, connect terminals 13 (TC) and 4 (CG) of the DLC3.
        • SST: 09843-18040 
        NOTE:
        • Confirm the terminal numbers before connecting them. Connecting the wrong terminals can damage the engine.
        • Turn all the electrical systems and the A/C off.
        • Check the ignition timing with the cooling fan off.
        • When checking the ignition timing, the shift lever should be in N or P.
        GTY519388Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        *a Front view of DLC3
      4. Start the engine and idle it.
      5. Using a timing light, check the ignition timing.

        Standard ignition timing

        8 to 12° BTDC @ idle

        NOTE:
        • Turn all the electrical systems and the A/C off.
        • Check the ignition timing with the cooling fan off.
        • When checking the ignition timing, the shift lever should be in N or P.
      6. Remove SST from the DLC3.
      7. Check the ignition timing.

        Standard ignition timing

        5 to 20° BTDC @ idle

        NOTE:
        • Turn all the electrical systems and the A/C off.
        • Check the ignition timing with the cooling fan off.
        • When checking the ignition timing, the shift lever should be in N or P.

        If the ignition timing is not as specified, check the valve timing.

      8. Check that the ignition timing advances immediately when the engine speed is increased.
      9. Turn the ignition switch off.
      10. Disconnect the timing light from the engine.
  9. INSPECT ENGINE IDLE SPEED 
    1. Warm up and stop the engine.
    2. When using the Techstream:
      1. Connect the Techstream to the DLC3.
      2. Race the engine at 2500 rpm for approximately 90 seconds.
      3. Turn the Techstream on.
      4. Start the engine and run it at idle.
      5. Enter the following menus: Powertrain / Engine / Data List / Engine Speed.

        Powertrain > Engine > Data List 

        Tester Display
        Engine Speed

        Standard idle speed

        750 to 850 rpm

        NOTE:
        • Turn all the electrical systems and the A/C off.
        • Check the ignition timing with the cooling fan off.
        • When checking the ignition timing, the shift lever should be in N or P.

        HINT: 

        Refer to the Techstream operator's manual for further details.

        If the idle speed is not as specified, check the air intake system.

      6. Disconnect the Techstream from the DLC3.
    3. When not using the Techstream:
      GTY506111Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of DLC3
      1. Using SST, connect a tachometer probe to terminal 9 (TAC) of the DLC3.
        • SST: 09843-18030 
        NOTE:

        Confirm the terminal number before connecting the probe. Connecting the wrong terminals can damage the engine.

      2. Race the engine at 2500 rpm for approximately 90 seconds.
      3. Check the idle speed.

        Standard idle speed

        750 to 850 rpm

        NOTE:
        • Turn all the electrical systems and the A/C off.
        • Check the ignition timing with the cooling fan off.
        • When checking the ignition timing, the shift lever should be in N or P.

        If the speed is not as specified, check the air intake system.

      4. Disconnect the tachometer probe from the DLC3.
  10. INSPECT COMPRESSION 
    1. Warm up and stop the engine.
    2. Check for DTCs.

      Refer to DTC CHECK / CLEAR [10/2014 - 05/2019]

    3. Remove the air cleaner case sub-assembly.

      Refer to REMOVAL [10/2014 - 05/2019]

      HINT: 

      Be sure not to remove the battery.

    4. Remove the 4 spark plugs.

      Refer to REMOVAL [10/2014 - ]

    5. Disconnect the fuel injector connector (for Port Injection).
      GTY505578Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    6. Disconnect the 2 fuel injector connectors (for Direct Injection).
      GTY519273Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    7. Check the cylinder compression pressure.
      1. Insert a compression gauge into the spark plug hole.
      2. Fully open the throttle.
      3. While cranking the engine, measure the compression pressure.

        Standard compression pressure

        1200 kPa (12.2 kgf/cm2 , 174 psi) or higher

        Minimum compression pressure

        900 kPa (9.2 kgf/cm2 , 131 psi)

        Pressure difference between each cylinder

        100 kPa (1.0 kgf/cm2 , 15 psi) or less

        NOTE:
        • Inspect the other cylinders in the same way.
        • Measure the compression pressure as quickly as possible.

        HINT: 

        Always use a fully charged battery to obtain an engine speed of 250 rpm or more.

      4. If the cylinder compression is low in one or more cylinders, pour a small amount of engine oil into the cylinder with low compression through its spark plug hole. Then inspect the cylinder compression pressure again.

        HINT: 

        • If adding oil helps boost the compression, it is likely that the piston rings and/or cylinder bore is worn or damaged.
        • If the pressure stays low, a valve may be stuck or seated improperly, or there may be leakage from the gasket.
    8. Connect the 2 fuel injector connectors (for Direct Injection).
    9. Connect the fuel injector connector (for Port Injection).
    10. Install the 4 spark plugs.

      Refer to INSTALLATION [10/2014 - ]

    11. Install the air cleaner case sub-assembly.

      Refer to INSTALLATION [10/2014 - 05/2019]

    12. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [10/2014 - 05/2019]

      NOTE:

      After the inspection, clear the DTCs, check for DTCs again and make sure the normal system code is output.

  11. INSPECT CO/HC 

    HINT: 

    This check determines whether or not the idle CO/HC complies with regulations.

    1. Start the engine.
    2. Keep the engine speed at 2500 rpm for approximately 180 seconds.
    3. Insert a CO/HC meter testing probe at least 40 cm (1.31 ft.) into the tailpipe during idling.
    4. Immediately check the CO/HC concentration at idle and at 2500 rpm.

      HINT: 

      • When performing the 2-mode (2500 rpm and idle) test, follow the measurement order prescribed by the applicable local regulations.
      • If the CO/HC concentration does not comply with regulations, troubleshoot in the order given below.
      1. Check the air fuel ratio sensor operation.

        Refer to PROCEDURE - Step 1 [10/2014 - ]

      2. Check the heated oxygen sensor operation.

        Refer to PROCEDURE - Step 1 [10/2014 - ]

      3. See the table below for possible causes, and then inspect and correct the applicable causes if necessary.
        CO HC Symptom Causes
        Normal High Rough idle
        1. Faulty ignition:

          - Incorrect timing

          - Fouled, shorted or improperly gapped plugs

        2. Incorrect valve clearance
        3. Leaky intake and exhaust valves
        4. Leaky cylinder
        Low High Rough idle
        (Fluctuating HC reading)
        1. Vacuum leaks:

          - PCV hose

          - Intake manifold

          - Throttle with motor body assembly

          - Brake booster line

        2. Lean mixture causing misfire
        High High Rough idle
        (Black smoke from exhaust)
        1. Restricted air cleaner filter element sub-assembly
        2. Plugged PCV valve
        3. Faulty SFI system:

          - Fuel pressure regulator assembly

          - Engine coolant temperature sensor

          - ECM

          - Fuel injector assemblies

          - Throttle with motor body assembly

          - Mass air flow meter
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