ECD SYSTEM Rough Idling or Excessive Engine Vibrations

DESCRIPTION

Malfunction Condition Main Trouble Area Related Trouble Area

  • Rough idling or juddering due to abnormal combustion

  • Juddering when vehicle is starting due to clutch system malfunctions

(a) Injector assembly malfunctions


  • Injector sliding malfunction

  • Injector stuck closed

  • Injector stuck open

  • Deposits in injector

  • Injector circuit malfunction

(b) Clutch system malfunctions


  • Clutch system (juddering when starting)

  • Injector compensation code

  • Fuel leak

  • Engine mounting

  • Intake system leakage

  • Intake system blockage

  • EGR system

  • Throttle valve system

  • Mass air flow meter sub-assembly

  • Fuel supply pump assembly (pre-stroke control valve)

  • Fuel pressure sensor

  • Low quality fuel

  • Vehicle modifications

  • Fuel filter element assembly air bleed problem

  • Accessory problem (A/C, generator, etc.)

  • ECM

Tech Tips


  • This troubleshooting procedure checks for the cause of rough idling and excessive engine vibrations.

  • Specified values in the following troubleshooting flowchart are for reference only. Variations in the Data List result values may occur depending on the measuring conditions or the vehicle's age. Do not judge the vehicle to be normal even when the Data List values indicate a standard level. There are possibly some concealed factors causing the malfunction.

  • Check that the vehicle has not been modified in any way prior to the vehicle inspection.


  1. Faults and Symptoms of Common Rail Diesel Components


    1. Engine Control

      Mass Air Flow Meter Sub-assembly
      Main fault Decrease in performance (foreign matter is stuck)
      Symptoms Lack of power, black smoke
      Data List MAF

      Tech Tips

      The maximum fuel injection volume is controlled according to the output from the mass air flow meter sub-assembly.
      Glow System
      Main fault Glow system malfunction
      Symptoms Difficult to start, rough idle, knocking, white smoke (when cold)
      Diagnostic Point

      • Measure the resistance of the glow plug

      • Check the glow plug indicator light
      Engine
      Main fault Loss of compression
      Symptoms Rough idle (lack of power always)
      Data List

      Engine Speed of Cyl


      • When cranking during the "Check the Cylinder Compression" Active Test, if there is a high speed cylinder, approx. 100 rpm more than the other cylinders, that cylinder may lose compression.

      Injection Feedback Val


      • When an Injector Feedback Val is more than 3 mm3/st, there may be a malfunction in the corresponding cylinder.

    2. Diesel Injection

      Fuel Supply Pump Assembly
      Main fault -
      Symptoms Difficult to start, engine stalling, rough idle, lack of power
      Data List

      Common Rail Pressure, Target Common Rail Pressure


      • Common Rail Pressure is within 5000 kPa of Target Common Rail Pressure during idling with the engine warmed up (engine coolant temperature is higher than 75°C (167°F)).

      • If the fuel pressure is 20000 kPa below the target pressure, then a lack of power will be felt.

      • If the fuel pressure is below 25000 kPa, then idling will be rough.

      Tech Tips

      The fuel pressure changes at engine start, but is approx. 25000 kPa at engine start after the engine is warmed up.
      Diagnostic Trouble Code Even if Common Rail Pressure is below Target Common Rail Pressure, a DTC will not be stored.
      Fuel Filter Element Assembly
      Main fault Blockage
      Symptoms Difficult to start, engine stalling, rough idle, lack of power
      Data List

      Common Rail Pressure, Target Common Rail Pressure


      • Common Rail Pressure is within 5000 kPa of Target Common Rail Pressure during idling with the engine warmed up (engine coolant temperature is higher than 75°C (167°F)).

      • If the fuel pressure is 20000 kPa below the target pressure, then a lack of power will be felt.

      • If the fuel pressure is below 25000 kPa, then idling will be rough.

      Tech Tips

      The fuel pressure changes at engine start, but is approx. 25000 kPa at engine start after the engine is warmed up.
      Diagnostic Trouble Code Even if Common Rail Pressure is below Target Common Rail Pressure, a DTC will not be stored.
      Injector Assembly
      Main fault Blockage
      Symptoms Rough idle, lack of power, black smoke, white smoke, knocking
      Data List

      Injection Feedback Val


      • When an Injector Feedback Val is more than 3 mm3/st, there may be a malfunction in the corresponding cylinder. This value can be read after idling for 1 minute.
      Fuel Pressure Sensor
      Main fault Open circuit, decrease in performance (foreign matter is stuck)
      Symptoms Difficult to start, rough idle, engine stall, lack of power
      Data List

      Common Rail Pressure, Target Common Rail Pressure


      • Slowly raise the engine speed from idling to 3000 rpm with the vehicle stopped and check that Common Rail Pressure follows Target Common Rail Pressure. If the fuel pressure sensor malfunctions, the actual fuel pressure may deviate from the target fuel pressure (either Common Rail Pressure decreases to a value less than Target Common Rail Pressure).
      Diagnostic Trouble Code When the fuel pressure sensor has a fault, some DTCs may be stored.
      Irregular Fuel
      Main fault -
      Symptoms Difficult to start, rough idle (especially when cold)

    3. Diesel EGR

      EGR System
      Main fault

      • Does not move smoothly

      • Does not close completely
      Symptoms

      • Rough idle

      • EGR valve stuck closed: A loud turbocharger sound.

      • EGR valve stuck open: Difficult to start (does not stall), black smoke, lack of power (if there is an excess in the quantity of EGR and there is a heavy load, when the vehicle starts moving, a lack of power will be felt).
      Data List

      Actual EGR Valve Pos, Target EGR Valve Pos


      • Generally, Actual EGR Valve Pos = Target EGR Valve Pos +/-5% (fully closed: 0%, fully open: 100%).

      • Using the EGR valve Active Test, check whether Actual EGR Valve Pos follows Target EGR Valve Pos (the engine coolant temperature and intake air temperature should be considered when a malfunction occurs).

      • EGR valve is fully closed when the engine switch is turned to on (IG) (engine stopped).

      • EGR valve opens to the halfway point at idling after the engine is warmed up.

      EGR Close Lrn. Val.


      • When leaving the vehicle idling, the normal range of EGR Close Lrn. Val. is 0 to 1 V.

      • In cases when EGR Close Lrn. Val. is out of the normal range (0 to 1 V), it is possible that the EGR valve cannot completely close.

    4. Diesel Throttle

      Diesel Throttle System
      Main fault Stuck, does not move smoothly
      Symptoms

      • Stuck closed: Lack of power, difficult to start, rough idle, engine stall, black smoke. These may occur when stuck almost fully closed.

      • Stuck open: Turbocharger sound increases. When the engine is stopped, engine vibrations may occur.
      Data List

      EGR Close Lrn. Val.


      • 0%: Fully closed

      • 100%: Fully open

      • When the engine switch is turned to on (IG) (the engine is stopped), the diesel throttle is fully open. When idling, the diesel throttle is at the halfway point. When the engine switch is turned from on (IG) to off, the throttle is fully closed temporarily.

  2. Data List Related to Rough Idling


    • Engine Speed

    • MAF

    • Intake Air

    • Coolant Temp

    • Engine Speed of Cyl #1 (to #4)

      (Output only when the "Check the Cylinder Compression" Active Test is performed)

    • Target Common Rail Pressure

    • Common Rail Pressure

    • Injection Feedback Val #1 (to #4)

    • Injection Volume

    • Actual Throttle Position

    • Target EGR Valve Pos

    • Actual EGR Valve Pos

    • EGR Close Lrn. Val.

CAUTION / NOTICE / HINT

Note

After replacing an injector assembly, the ECM needs registration Click here.

PROCEDURE


  1. CHECK MALFUNCTION CONDITION


    1. Identify when shuddering occurs.

      Result
      Result Proceed to
      When idling A
      When engaging engine clutch at vehicle start

      B

      (Clutch system shudders)

    B

    REPAIR OR REPLACE CLUTCH SYSTEM

    A

  2. CHECK WIRE HARNESS AND CONNECTION IN ENGINE COMPARTMENT


    1. Check the wire harness and connector connections of common rail system components.

      OK
      The wire harnesses and connectors are connected securely.

      Tech Tips

      The engine may have problems when there is an intermittent disconnection in a circuit related to the fuel pressure sensor, crankshaft position sensor, engine coolant temperature sensor, etc.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR Click here

    OK

  3. READ OUTPUT DTC (RELATING TO ENGINE)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG) and turn the GTS on.

    3. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    4. Read the pending DTCs.


      Powertrain > Engine and ECT > Trouble Codes
      Result
      Result Proceed to
      No DTCs are output A
      Engine related DTCs are output B

      Tech Tips

      If only DTC P1605 is output, proceed to step 4.


    B

    GO TO DTC CHART Click here

    A

  4. TAKE SNAPSHOT DURING IDLING (PROCEDURE 4)


    1. Connect the GTS to the DLC3.

    2. Start the engine and turn the GTS on.

    3. Warm up the engine (engine coolant temperature is 75°C (167°F) or higher).

    4. Enter the following menus: Powertrain / Engine and ECT / Data List / Diesel Rough Idle.

    5. Take a snapshot when idling with no load after the engine is warmed up and when the problem is occurring.

      Tech Tips


      • A snapshot can be used to compare vehicle data from the time of the malfunction to normal data and is very useful for troubleshooting.

      • The shift lever should be in neutral and the A/C switch and all accessory switches should be off.

      • If rough idling occurs when the A/C switch is on, take another snapshot with the A/C switch on.

      • Take a snapshot when the problem is occurring, such as when the engine is cold. However, if the problem does not reoccur, it is acceptable to only take a snapshot after the engine is warmed up.

      Result
      Proceed to
      NEXT

    NEXT

  5. CHECK WHITE SMOKE


    1. Start the engine.

    2. Fully depress the accelerator pedal, and then release it.

    3. Check whether white smoke is emitted when racing the engine.

      Note

      Be sure not to check for white smoke indoors.

      Tech Tips

      Depending on whether there is oil mixed with the fuel, or whether there is unburned fuel present, the smell of the exhaust gas differs. When oil is mixed in, the exhaust gas smells such as burning oil.

      Result
      Result Proceed to
      White smoke is not emitted A
      White smoke is emitted B

    B

    CHECK AND REPAIR ENGINE ASSEMBLY Click here

    A

  6. CHECK DATA LIST (ENGINE SPEED)


    1. Check engine speed in the snapshot taken in procedure 4 when the engine was idling.

      Result
      Result Proceed to
      Change in engine speed coincides with air conditioning system operation B
      Except above A

    B

    CHECK AIR CONDITIONING SYSTEM Click here

    A

  7. CHECK DATA LIST (INJECTION FEEDBACK VAL #1 TO #4)


    1. Check Injection Feedback Val # in the snapshot taken in procedure 4 when the engine was idling.

      Result
      Result Result

      Injection Feedback Val for at least one cylinder is more than +3 mm3/st and engine vibration is abnormally large

      		 A
      Except above B

      Tech Tips


      • When there is a problem with the operation of an injector assembly due to foreign matter in the inside of the injector assembly, etc., the fuel injection volume decreases. As a result, the ECM gives instructions to increase the fuel injection volume, which causes Injection Feedback Val to increase.

      • The ECM controls the system so that the sum of Injection Feedback Val for all of the cylinders is approximately 0 mm3/st. Even if the value of Injection Feedback Val for a cylinder is less than -3.0 mm3/st, as long as the value of Injection Feedback Val for each of the other cylinders is 3.0 mm3/st or less, the injector assemblies are not malfunctioning.


    B

    CHECK DATA LIST (COMMON RAIL PRESSURE AND TARGET COMMON RAIL PRESSURE) Click here

    A

  8. INSPECT INJECTOR COMPENSATION CODE


    1. Read the injector compensation code.

      Click here

      OK
      Compensation codes stored in the ECM match compensation codes of the installed injector assemblies.
      Result
      Proceed to
      OK
      NG

    NG

    GO TO STEP 13 Click here

    OK

  9. PERFORM ACTIVE TEST USING GTS (CONTROL THE SELECT CYLINDER FUEL CUT)

    Tech Tips

    Use this Active Test to determine the malfunctioning cylinder.


    1. Connect the GTS to the DLC3.

    2. Start the engine and turn the GTS on.

    3. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Select Cylinder Fuel Cut.

      Tech Tips


      • If the engine idle speed does not change when an injector assembly is disabled, the cylinder being tested is malfunctioning.

      • If the cylinder being tested is normal, there will be a significant change in idle speed when the fuel injection is stopped for that cylinder.


      Powertrain > Engine and ECT > Active Test
      Tester Display
      Control the Select Cylinder Fuel Cut
      Result
      Proceed to
      NEXT

    NEXT

  10. REPLACE INJECTOR ASSEMBLY OF MALFUNCTIONING CYLINDER


    1. Replace the injector assembly of the malfunctioning cylinder.

      Click here

      Note


      • When replacing the injector assembly for a cylinder, always be sure to use a new No. 1 injection pipe sub-assembly and a new No. 2 injection pipe sub-assembly.

      • Follow the procedure in the repair manual and temporarily install the No. 1 injection pipe sub-assembly, No. 2 injection pipe sub-assembly and No. 1 nozzle leakage pipe assembly, and then correctly position the injector assemblies. After that, tighten parts according to the torque specifications.

      • If the installation procedure is not performed correctly, injector assemblies may become out of position, which may cause the injector assemblies to deteriorate, resulting in malfunctions.

      • If an injector assembly deteriorates and malfunctions, other problems such as knocking, rough idle, etc. may occur.

      • If an injector assembly becomes out of position, it is possible that the seal between the injector assembly and injection pipe sub-assembly may become incomplete, resulting in a fuel leak.

      Result
      Proceed to
      NEXT

    NEXT

  11. CLEAN FUEL FILTER CASE AND REPLACE FUEL FILTER ELEMENT ASSEMBLY


    1. Clean the fuel filter case and replace the fuel filter element assembly.

      Tech Tips

      Be sure to clean the inside of the fuel filter case as the injector assemblies may not operate properly if the fuel filter element assembly is installed with foreign matter remaining inside the fuel filter case.

      Result
      Proceed to
      NEXT

    NEXT

  12. BLEED AIR FROM FUEL SYSTEM


    1. Bleed the air from the fuel system.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  13. REGISTER INJECTOR COMPENSATION CODE AND PERFORM PILOT QUANTITY LEARNING


    1. Register the injector compensation code.

      Click here


      Powertrain > Engine and ECT > Utility
      Tester Display
      Injector Compensation

    2. Perform the injector pilot quantity learning.

      Click here


      Powertrain > Engine and ECT > Utility
      Tester Display
      Pilot Quantity Learning
      Result
      Proceed to
      NEXT

    NEXT

    GO TO STEP 29 Click here

  14. CHECK DATA LIST (COMMON RAIL PRESSURE AND TARGET COMMON RAIL PRESSURE)


    1. Check engine speed in the snapshot taken in procedure 4 when the engine was idling after having been warmed up.

      Result
      Result Proceed to

      Difference between Common Rail Pressure and Target Common Rail Pressure is 5000 kPa (51.0 kgf/cm2, 725 psi) or more

      		 A
      Except above B

    B

    CHECK DATA LIST (EGR RATE DIFFERENTIAL (ACTUAL-TARGET)) Click here

    A

  15. INSPECT CLOGGED FUEL PIPE


    1. Connect the GTS to the DLC3.

    2. Start the engine and turn the GTS on.

    3. Enter the following menus: Powertrain / Engine and ECT / Data List / Target Common Rail Pressure and Common Rail Pressure.


      Powertrain > Engine and ECT > Data List
      Tester Display
      Target Common Rail Pressure
      Common Rail Pressure

    4. With no load after the engine is warmed up, take a snapshot when idling and vehicle was accelerating with the accelerator pedal fully depressed in 2nd gear.

    5. Check the Target Common Rail Pressure and Common Rail Pressure.

      B003S64E04
      Result
      Result Proceed to
      While idling the vehicle, "Common Rail Pressure" deviates from the normal range and varies periodically with a period of approximately 2 seconds or more*1 A
      "Common Rail Pressure" is normal while idling the vehicle, but "Common Rail Pressure" does not follow "Target Common Rail Pressure" when the accelerator pedal is fully depressed in 2nd gear*2
      Except above B

      Note


      • *1: The cause may be a squashed or blocked fuel pipe or hose.

      • *2: The cause may be a clogged fuel filter element assembly.


    B

    REPLACE FUEL SUPPLY PUMP ASSEMBLY (PRE-STROKE CONTROL VALVE) Click here

    A

  16. REPAIR OR REPLACE CLOGGED FUEL LINE


    1. Repair or replace the clogged (including frozen fuel) fuel pipe.

    2. Replace the fuel filter element assembly.

      Tech Tips

      If "Common Rail Pressure" does not follow "Target Common Rail Pressure" when the accelerator pedal is fully depressed in 2nd gear, replace the fuel filter element assembly.

      Result
      Proceed to
      NEXT

    NEXT

  17. BLEED AIR FROM FUEL SYSTEM


    1. Bleed the air from the fuel system.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

    GO TO STEP 29 Click here

  18. CHECK AIR CONDITIONING SYSTEM


    1. Check the air conditioning system.

      Tech Tips


      • Be sure to check the air conditioning hoses and pipes.

      • Check the refrigerant pressure.

        Click here

      Result
      Proceed to
      NEXT

    NEXT

    GO TO STEP 29 Click here

  19. REPLACE FUEL SUPPLY PUMP ASSEMBLY (PRE-STROKE CONTROL VALVE)


    1. Replace the fuel supply pump assembly.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  20. BLEED AIR FROM FUEL SYSTEM


    1. Bleed the air from the fuel system.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

    GO TO STEP 29 Click here

  21. REPAIR OR REPLACE HARNESS AND CONNECTOR


    1. Repair or replace the harness or connector.

      Result
      Proceed to
      NEXT

    NEXT

    GO TO STEP 29 Click here

  22. CHECK AND REPAIR ENGINE ASSEMBLY


    1. Check the following items and repair the malfunctioning part if necessary.


      1. Check the cylinder compression pressure.

        Click here

      Result
      Proceed to
      NEXT

    NEXT

    GO TO STEP 29 Click here

  23. CHECK DATA LIST (EGR RATE DIFFERENTIAL (ACTUAL-TARGET))


    1. Check EGR Rate Differential (Actual-Target) in the snapshot taken in procedure 4 when the engine was idling.

      Result
      Result Result
      EGR Rate Differential (Actual-Target) of +30% or more is displayed A
      Except above B

    B

    PERFORM ACTIVE TEST USING GTS (ACTIVATE THE EGR VALVE CLOSE) Click here

    A

  24. CHECK FOR DEPOSIT (ELECTRIC EGR CONTROL VALVE ASSEMBLY)


    1. Remove the electric EGR control valve assembly.

      Click here

    2. Visually check the electric EGR control valve assembly for deposits. If there are deposits, clean the electric EGR control valve assembly.

      Note


      • When cleaning the electric EGR control valve assembly, make sure the valve is completely closed.

      • When cleaning the electric EGR control valve assembly, perform initialization procedure.

        Click here

      • Do not forcibly open the valve, as it may be damaged or deformed.

      • When cleaning the electric EGR control valve assembly, use a piece of cloth soaked with cleaning solvent.

        Spraying the solvent directly onto these parts or soaking the parts in the solvent may damage the parts.

      • When cleaning the EGR control valve, care should be taken to prevent the ingress of cleaning solvent into the bearings of valve shaft, and when wiping off deposits on the EGR control valve, care should be taken not to push the deposits into the bearings of valve shaft. These contaminants may adversely affect on the function of EGR control valve.

      Tech Tips


      • If the EGR valve does not open properly or is stuck closed, the amount of intake air increases and combustion sounds and engine vibration may increase.

      • If the EGR valve does not close properly or is stuck open, EGR becomes excessive and combustion becomes unstable. Also, there may be a lack of power. In this case, clean the electric EGR control valve assembly.

    3. Reinstall the electric EGR control valve assembly.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

    GO TO STEP 29 Click here

  25. PERFORM ACTIVE TEST USING GTS (ACTIVATE THE EGR VALVE CLOSE)


    1. Connect the GTS to the DLC3.

    2. Start the engine and warm it up, and make sure the A/C switch and all accessory switches are off.

    3. Turn the engine switch off. Wait for 30 seconds, and then restart the engine.

    4. Turn the GTS on.

    5. Enter the following menus: Powertrain / Engine and ECT / Data List / MAF.


      Powertrain > Engine and ECT > Data List
      Tester Display
      MAF

    6. Read the MAF value displayed on the GTS while the engine is idling.

    7. Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the EGR Valve Close / Data List / MAF.


      Powertrain > Engine and ECT > Active Test
      Active Test Display
      Activate the EGR Valve Close
      Data List Display
      MAF

    8. Read the MAF value when the EGR valve is closed using the Active Test function.

      Tech Tips


      • If idling continues for 20 minutes or more, the EGR valve target opening angle becomes 0% (EGR valve fully closed). As this makes diagnosis impossible, it becomes necessary to drive the vehicle or restart the engine.

      • Before performing the diagnosis, confirm that the EGR valve target opening angle is not 0%.

      Result
      Active Test Result Proceed to

      Activate the EGR Valve Close:

      Off (Open) to On (Closed)

      		 MAF value does not change A
      MAF value changes B

      Note

      As the measured values may differ from those shown below due to factors such as differences in measuring environments and changes in vehicle condition due to aging, do not use these values to determine whether the vehicle is malfunctioning or not.

      Tech Tips

      The problem may be a temporary one, due to the entry of deposits or foreign matter. Check that there are no deposits or foreign matter in the electric EGR control valve assembly or mass air flow meter.

      Reference
      EGR Valve Condition (Opening) Measuring Condition MAF (Reference)
      Open (55%)

      • Atmosphere pressure: 101 kPa

      • Engine coolant temperature: 75°C (167°F)

      		 3 to 7 gm/sec
      Closed (0%) 11 to 16 gm/sec

    A

    GO TO STEP 24 Click here

    B

  26. PERFORM PILOT QUANTITY LEARNING (DETAIL)


    1. Perform the pilot quantity learning (detail).

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  27. CHECK ROUGH IDLING OR EXCESSIVE ENGINE VIBRATIONS


    1. Check rough idling or excessive engine vibrations.

      Result
      Result Proceed to
      Rough idling or excessive engine vibrations do not occur A
      Except above B

    A

    END

    B

  28. CHECK AND REPLACE ENGINE MOUNTING INSULATOR


    1. Check the following items and repair or replace the malfunctioning part if necessary.


      1. Check that the engine mounting insulators are installed correctly.

      2. Check that the engine mounting insulators are not twisted.

      3. Check that deformation of an engine mounting insulator is not causing the engine to contact the vehicle body.

      Result
      Proceed to
      NEXT

    NEXT

  29. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

    Result
    Proceed to
    NEXT

    NEXT

    END