ECD SYSTEM (w/ EGR Cooler) Lack of Power or Hesitation

DESCRIPTION

Malfunction Condition Main Trouble Area Related Trouble Area

  • Lack of power caused by abnormal fuel injection volume (supply pump malfunction or injector malfunction etc.)

  • Lack of power caused by intake air volume shortage (turbocharger malfunction, or front exhaust pipe or exhaust manifold converter blocked)

(a) Injector malfunctions


  • Injector sliding malfunction

  • Injector stuck closed

  • Injector stuck open

  • Deposits in injector

  • Injector circuit malfunction

(b) Abnormal common rail pressure


  • Supply pump

(c) Abnormal intake air volume


  • Intake air system leakage

  • Turbocharger

  • Front exhaust pipe blockage

  • Exhaust manifold converter blockage

  • Pressure discharge valve (P1271 set simultaneously)

  • Intake air system blockage

  • EGR system

  • Fuel filter element is clogged

  • Throttle valve

  • Mass air flow meter

  • Compression pressure

  • Injector compensation code

  • Fuel leak

  • Glow plug

  • Fuel pressure sensor

  • Manifold absolute pressure sensor

  • Vacuum hose connection for manifold absolute pressure sensor

  • EDU (P0200 set simultaneously)

  • Vehicle modifications

  • Clutch disc wear

  • Low quality fuel

  • Frozen fuel

  • ECM

Tech Tips


  • Specified values in the following troubleshooting flowchart are for reference only. Variations in the Data List 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.

  • This troubleshooting procedure checks for the cause of an obvious lack of engine power while the vehicle is being driven (such as the maximum speed being extremely low).


  1. Faults and Symptoms of Common Rail Diesel Components


    1. Engine Control

      Mass Air Flow Meter
      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.
      Intake System
      Symptom: Main fault

      • Lack of power (no black smoke): air filter blockage, air duct is crushed/leaking

      • Black smoke (no lack of power): Leakage between the turbo and intake manifold
      Data List

      • MAP (inside intake air pressure)

      • Target Booster Pressure

        When the accelerator is fully depressed, if MAP is 20 kPa lower than Target Booster Pressure for more than 5 seconds then a lack of power will be felt.

      • MAF
      Turbocharger System
      Main fault

      • Air leak in the turbocharged air passage

      • Turbocharger (turbine, bearing, variable nozzle)
      Symptoms

      Lack of power (when vehicle starting, when heavy load)

      (Black smoke is not emitted when racing while vehicle stopped)
      Data List

      MAP (inside intake air pressure), Target Booster Pressure


      • When the accelerator is fully depressed, if MAP is 20 kPa lower than Target Booster Pressure for more than 5 seconds then a lack of power will be felt.

      • With the ignition switch ON or during idling, MAP = atmospheric pressure (standard atmospheric pressure = 101 kPa). When the engine speed is about 1500 rpm or more, the turbocharger starts to take effect and MAP becomes higher than atmospheric pressure.

      • Atmospheric pressure decreases 1 kPa each time altitude increases by 100 m, and is also affected by the current weather conditions.
      Exhaust System
      Main fault Blockage
      Symptoms Lack of power (high engine speed, when heavy load)
      Data List

      MAP (inside intake air pressure), Target Booster Pressure

      When the accelerator is fully depressed, if MAP is 20 kPa lower than Target Booster Pressure for more than 5 seconds then a lack of power will be felt.
      Glow System
      Main fault Open circuit, glow plug relay fault
      Symptoms Difficult to start, rough idle, knocking, white smoke (when cold)
      Data List Check the glow plug indicator light
      Diagnostic Point Try to measure the resistance of the glow plug
      Engine - 1
      Main fault Damaged, seized up
      Symptoms Cannot crank, crank speed is low, strange noise
      Engine - 2
      Main fault Loss of compression
      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


      • If Injection Feedback Val is more than 3 mm3/st, the cylinder may have a fault.

    2. Diesel Injection

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

      Fuel Press, Target Common Rail Pressure, Target Pump SCV Current


      • At a stable condition (e.g. Idling), Fuel Press is within +/-5000 kPa of "Target Common Rail Pressure".

      • 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.

      • If Target Pump SCV Current is 3000 mA or more, the suction control valve may be stuck.

      Tech Tips


      • The fuel pressure changes at engine starting, but is approx. 25000 kPa at engine start after the engine is warmed up.

      • When Target Pump SCV Current is 3000 mA or more, the suction control valve has a tendency to become stuck.
      Diagnostic Trouble Code Even if Fuel Press is less than Target Common Rail Pressure, a DTC will not be stored.
      Fuel Filter
      Main fault Blockage
      Symptoms Difficult to start, engine stalling, rough idle, lack of power
      Data List

      Fuel Press, Target Common Rail Pressure


      • At a stable condition (e.g. Idling), the fuel pressure is within +/-5000 kPa of "Target Common Rail Pressure".

      • 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 starting, but is approx. 25000 kPa at engine start after the engine is warmed up.
      Diagnostic Trouble Code Even if Fuel Press is less than Target Common Rail Pressure, a DTC will not be stored.
      Fuel Injector
      Main fault Blockage
      Symptoms Rough idle, lack of power, black smoke, white smoke, knocking
      Data List

      Injection Feedback Val


      • When an Injection Feedback Val is more than 3 mm3/st, the cylinder is not normal. This can be read after idling for 1 minute with the engine warmed up (engine coolant temperature is higher than 70°C (158°F)).
      Injector Driver (EDU)
      Main fault Circuit fault: The fuel injector does not open.
      Symptoms Difficult to start, rough idle, lack of power, black smoke, white smoke, knocking
      Data List Same as fuel injector
      Diagnostic Trouble Code When the EDU has a fault, some DTCs may be stored.
      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

      Fuel Press, Target Common Rail Pressure


      • At a stable condition (e.g. Idling), Fuel Press is within +/-5000 kPa of "Target Common Rail Pressure".
      Diagnostic 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 fully
      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, jerking (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. Also, when racing the engine, there will be some black smoke).
      Data List

      Actual EGR Valve Pos., Target EGR Position


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

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

      • EGR valve is fully closed when the ignition switch is ON (engine stopped).

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

      • When the EGR valve does not close, MAF (Mass Air Flow) decreases when the vehicle is accelerated at full throttle. MAP also decreases in comparison to Target Booster Pressure, however there is not a large difference.

      EGR Close Lrn. Val., EGR Close Lrn. Status


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

      • In cases when EGR Close Lrn. Status. is NG or 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

      • Actual Throttle Position (fully closed 100%, fully open 0%)

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

  2. Data List Related to Lack of Power


    • Engine Speed

    • MAP

    • MAF

    • Intake Air

    • Coolant Temp

    • Target Common Rail Pressure

    • Fuel Press

    • Target Pump SCV Current

    • Injection Feedback Val #1 (to #4)

    • Injection Volume

    • Actual Throttle Position

    • Target EGR Position

    • Actual EGR Valve Pos.

INSPECTION PROCEDURE


  1. Explanation of Symptom

    Lack of Power

    The power of the diesel engine is determined by the quantity of injected fuel and the quantity of intake air.

    The quantity of injected fuel is determined by the fuel pressure and the amount of time the injector is open for. Basically, the fuel pressure is controlled to reach the target fuel pressure. The throttle valve does not restrict air flow volume, so the manifold absolute pressure is almost the same as atmospheric pressure when idling. At more than approximately 1500 rpm, the turbo starts to operate causing the manifold absolute pressure to become higher than atmospheric pressure.

    The manifold absolute pressure is controlled to reach the Target Booster Pressure when accelerating the vehicle at full throttle. Also, when accelerating the vehicle at full throttle, the throttle is fully open and the EGR valve is fully closed, preserving the mass air flow.

    Note


    • After replacing the ECM, the new ECM needs registration Click here and initialization Click here.

    • After replacing the fuel supply pump, the ECM needs initialization Click here.

    • After replacing a fuel injector, the ECM needs registration Click here.

PROCEDURE


  1. READ OUTPUT DTC (RELATING TO ENGINE)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester on.

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

    4. Read pending DTCs.

      Result
      Result Proceed to
      No DTCs are output A
      Engine related DTCs are output B

    B

    GO TO DTC CHART

    A

  2. TAKE SNAPSHOT DURING IDLING AND 4000 rpm


    1. A01DUXVE02

      Connect the intelligent tester to the DLC3.

    2. Start the engine and turn the tester on.

    3. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data.

    4. With no load after the engine is warmed up, take a snapshot when idling and at 4000 rpm.

      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.

      • Graphs can be displayed by transferring the stored snapshot data from the tester to a PC. Intelligent Viewer must be installed on the PC.

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


    NEXT

  3. TAKE SNAPSHOT DURING LACK OF POWER


    1. A01DUXVE02

      Connect the intelligent tester to the DLC3.

    2. Start the engine and turn the tester on.

    3. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data.

    4. Take a snapshot of the following Data List items with the intelligent tester during lack of power.

      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.

      • Graphs can be displayed by transferring the stored snapshot data from the tester to a PC. Intelligent Viewer must be installed on the PC.

      • Move the shift lever to 2nd gear and accelerate the vehicle with the accelerator pedal fully depressed (obey all laws and regulations, and pay attention to traffic conditions while driving the vehicle). Then, check the Data List with the engine warmed up and idling (the shift lever in neutral and the A/C switch and all accessory switches off).

      • Examples of Actual Malfunctions (See "Diagnostic Help" menu)


        • Lack of power caused by overly low boost pressure

        • Lack of power caused by overly low MAF

        • EGR valve stuck in open position

      • For engine protection, exhaust gas or fuel economy related reasons, there are some ranges of engine operation where engine power feels like it flattens out, but this is not a malfunction.

      • The above values were measured under standard atmospheric pressure. The values are influenced by elevation, weather conditions, etc.

        Standard atmospheric pressure is 101 kPa. For every 100 m increase in altitude, pressure drops by 1 kPa. Varies by weather.

      • The engine speed must be 1500 rpm or less before performing the inspection in which the accelerator pedal is fully depressed and the engine is accelerated to a speed of 3000 rpm.

    5. Check for a lack of power during the driving test.

      Result
      Result Proceed to
      Apparent lack of power is present A
      Apparent lack of power is not present B

    B

    COMPARE WITH SIMILAR VEHICLE WITH SAME ENGINE Click here

    A

  4. CHECK SNAPSHOT (MAP AND MAF)


    1. Check MAP and MAF in the snapshot taken when the engine was running at 4000 rpm with no load.

      Result
      Result Proceed to
      MAP is 117 kPa or more and MAF is 84 gm/s. or more*1 A
      MAP is less than 90 kPa*2 B
      Except above*3 C

      Tech Tips

      The above values were measured under standard atmospheric pressure. The values are influenced by elevation, weather conditions, etc.

      Standard atmospheric pressure is 101 kPa. For every 100 m increase in altitude, pressure drops by 1 kPa. Varies by weather.

      *1: There may be a problem in the fuel injection system.

      *2: There may be a problem in the turbocharger system.

      *3: There may be a problem in the intake system or a problem with the EGR valve (valve stuck open or valve does not close).


    B

    READ VALUE USING INTELLIGENT TESTER (MAP AND ATMOSPHERIC PRESSURE) Click here

    C

    CHECK AIR INTAKE SYSTEM Click here

    A

  5. CHECK SNAPSHOT (FUEL PRESS, TARGET COMMON RAIL PRESSURE, MAP AND TARGET BOOSTER PRESSURE)


    1. Check Fuel Press, Target Common Rail Pressure, MAP and Target Booster Pressure in the snapshot taken when the vehicle was accelerating with the accelerator pedal fully depressed in 2nd gear.

      Result
      Result Proceed to
      MAP is less than 205 kPa at an engine speed of 3000 rpm A
      Difference between Fuel Press and Target Common Rail Pressure is +/-20000 kPa or more B
      Except above C

      Tech Tips


      • The above values were measured under standard atmospheric pressure. The values are influenced by elevation, weather conditions, etc.

        Standard atmospheric pressure is 101 kPa. For every 100 m increase in altitude, pressure drops by 1 kPa. Varies by weather.

      • The engine speed must be 1500 rpm or less before performing the inspection in which the accelerator pedal is fully depressed and the engine is accelerated to a speed of 3000 rpm.

      • If the turbocharger movement is not smooth, etc., the value of MAP in the snapshot taken during lack of power will not reach the target value.

        When the accelerator pedal is fully depressed and the engine speed is 3000 rpm, the MAP should be more than 205 kPa.


    B

    BLEED AIR FROM FUEL SYSTEM Click here

    C

    CHECK AIR INTAKE SYSTEM Click here

    A

  6. CHECK INTAKE SYSTEM


    1. Check for air leakage and blockage between the air cleaner and turbocharger, and between the turbocharger and intake manifold.

      Tech Tips


      • Check that the intercooler is not clogged with foreign matter.

      • Check that there are no disconnected, pinched or leaking hoses or pipes.

      • Check that there are no modifications made by the user.

      OK
      No leakage or blockage.

    NG

    REPAIR OR REPLACE AIR INTAKE SYSTEM Click here

    OK

  7. CLEAN FUEL FILTER CASE AND REPLACE FUEL FILTER


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

      Tech Tips

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


    NEXT

  8. REPLACE FUEL INJECTORS OF ALL CYLINDERS


    1. Replace the fuel injectors Click here.


    NEXT

  9. BLEED AIR FROM FUEL SYSTEM


    1. Bleed the air from the fuel system Click here.


    NEXT

  10. REGISTER INJECTOR COMPENSATION CODE AND PERFORM PILOT QUANTITY LEARNING


    1. Register the injector compensation code Click here.

    2. Perform the fuel injector pilot quantity learning Click here.


    NEXT

  11. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    NEXT

    END

  12. READ VALUE USING INTELLIGENT TESTER (MAP AND ATMOSPHERIC PRESSURE)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester on.

    3. Enter the following menus: Powertrain / Engine and ECT / Data List / MAP and Atmosphere Pressure.

    4. Compare MAP to Atmosphere Pressure when the ignition switch is ON (do not start the engine).

      Standard
      Difference between MAP and Atmosphere Pressure is less than 8 kPa.

      Tech Tips


      • If MAP and Atmosphere Pressure have the same value, both are normal. If there is a difference of 8 kPa or more, compare the values to the atmospheric pressure for that day. The sensor whose deviation is the greatest is malfunctioning.

      • Standard atmospheric pressure is 101 kPa. For every 100 m increase in altitude, pressure drops by 1 kPa. This varies by weather.

      Result
      Result Proceed to
      MAP and Atmosphere Pressure have the same value A
      MAP is different from actual atmospheric pressure B
      Atmosphere Pressure is different from actual atmospheric pressure C

    B

    REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR Click here

    C

    REPLACE ECM Click here

    A

  13. CHECK AIR INTAKE SYSTEM


    1. Check for air leaks and blockages between the air cleaner case and turbocharger, and between the turbocharger and intake manifold.

      Result
      Result Proceed to
      Leaks and/or blockages exist in the intake system A
      No leaks or blockages in the intake system B

      Tech Tips


      • Inspect the air intake system, especially hoses and pipes between the air cleaner and turbocharger.

      • Check for abnormal disconnections, pipe and hose squashing, and any damage in the intake system.

      • Using your hand, check whether the pipes and hoses in the intake system are securely connected.

      • When inspecting for a clogged intake system (cause of low MAP), check the following points:


        • Clogged air cleaner

        • Clogged intake hose

        • Diesel throttle valve stuck in closed position

      • Check for any modifications in the intake system made by the user.


    B

    REPLACE TURBOCHARGER SUB-ASSEMBLY Click here

    A

  14. REPAIR OR REPLACE AIR INTAKE SYSTEM


    1. Repair or replace the malfunctioning part in the air intake system.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  15. REPLACE TURBOCHARGER SUB-ASSEMBLY


    1. Replace the turbocharger sub-assembly Click here.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  16. REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR


    1. Replace the manifold absolute pressure sensor.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  17. REPLACE ECM


    1. Replace the ECM Click here.


    NEXT

  18. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    NEXT

    END

  19. BLEED AIR FROM FUEL SYSTEM


    1. Bleed the air from the fuel system Click here.


    NEXT

  20. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (TEST THE FUEL LEAK)


    1. Connect the intelligent tester to the DLC3.

    2. Start the engine and turn the tester on.

    3. Enter the following menus: Powertrain / Engine and ECT / Active Test / Test the Fuel Leak / Data List / Fuel Press, Target Common Rail Pressure.

    4. A01DUXVE02

      Take a snapshot with the intelligent tester during the Active Test.

      Tech Tips

      Detailed graphs can be displayed by transferring the stored snapshot from the tester to a PC (personal computer) with Intelligent Viewer installed.

    5. Measure the difference between the target fuel pressure (Target Common Rail Pressure) and the actual fuel pressure (Fuel Press) when the "Test the Fuel Leak" Active Test is performed.

      Tech Tips

      In order to obtain an exact measurement, perform the Active Test 5 times and measure the difference once each time the Active Test is performed.

      A01DZBQE01
      OK
      The difference between the target fuel pressure and the actual fuel pressure 2 seconds after the Active Test starts is less than 10000 kPa.

      Tech Tips


      • "Target Common Rail Pressure" is the target fuel pressure controlled by the ECM.

      • "Fuel Press" is the actual fuel pressure.


    NG

    CHECK IF FUEL IS BEING SUPPLIED TO FUEL SUPPLY PUMP Click here

    OK

    END

  21. CHECK IF FUEL IS BEING SUPPLIED TO FUEL SUPPLY PUMP


    1. Disconnect the inlet hose from the fuel supply pump.

    2. Operate the priming pump and check that fuel is being supplied to the fuel supply pump.

      OK
      Fuel is properly supplied to the fuel supply pump when the priming pump is operated.

      Tech Tips


      • When there is a lack of fuel, the fuel pressure drops.

      • Inspect for fuel filter clogging.


    NG

    REPAIR OR REPLACE CLOGGED FUEL PIPE (INCLUDING FROZEN FUEL) (FUEL TANK - FUEL SUPPLY PUMP) Click here

    OK

  22. REPLACE FUEL SUPPLY PUMP


    1. Replace the fuel supply pump Click here.


    NEXT

    BLEED AIR FROM FUEL SYSTEM Click here

  23. REPAIR OR REPLACE CLOGGED FUEL PIPE (INCLUDING FROZEN FUEL) (FUEL TANK - FUEL SUPPLY PUMP)


    1. Check and repair or replace the clogged fuel pipe.


    NEXT

  24. BLEED AIR FROM FUEL SYSTEM


    1. Bleed the air from the fuel system Click here.


    NEXT

  25. PERFORM FUEL SUPPLY PUMP INITIALIZATION


    1. Perform fuel supply pump initialization Click here.


    NEXT

  26. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the intelligent tester to the DLC3.

    2. Start the engine and turn the tester on.

    3. Enter the following menus: Powertrain / Engine and ECT / Active Test / Test the Fuel Leak / Data List / Fuel Press, Target Common Rail Pressure.

    4. A01DUXVE02

      Take a snapshot with the intelligent tester during the Active Test.

      Tech Tips

      Detailed graphs can be displayed by transferring the stored snapshot from the tester to a PC (personal computer) with Intelligent Viewer installed.

    5. Measure the difference between the target fuel pressure (Target Common Rail Pressure) and the actual fuel pressure (Fuel Press) when the "Test the Fuel Leak" Active Test is performed.

      Tech Tips

      In order to obtain an exact measurement, perform the Active Test 5 times and measure the difference once each time the Active Test is performed.

      A01DZBQE01
      OK
      The difference between the target fuel pressure and the actual fuel pressure 2 seconds after the Active Test starts is less than 10000 kPa.

      Tech Tips


      • "Target Common Rail Pressure" is the target fuel pressure controlled by the ECM.

      • "Fuel Press" is the actual fuel pressure.


    NEXT

    END

  27. CHECK AIR INTAKE SYSTEM


    1. Check for air leaks and blockages between the air cleaner case and turbocharger, and between the turbocharger and intake manifold.

      Result
      Result Proceed to
      No leaks or blockages in the intake system A
      Leaks and/or blockages exist in the intake system B

      Tech Tips


      • Inspect the air intake system, especially hoses and pipes between the air cleaner and turbocharger.

      • Check for abnormal disconnections, pipe and hose squashing, and any damage in the intake system.

      • Using your hand, check whether the pipes and hoses in the intake system are securely connected.

      • By applying soapy water and revving up the engine, air leaks from the intake system can be checked by checking for bubbles.

      • Make sure that the hose between the manifold absolute pressure sensor and intake manifold is not loose or disconnected.

      • Check for any modifications in the intake system made by the user.


    B

    REPAIR OR REPLACE AIR INTAKE SYSTEM Click here

    A

  28. INSPECT TURBOCHARGER SUB-ASSEMBLY


    1. Inspect the turbocharger sub-assembly Click here.


    NG

    REPLACE TURBOCHARGER SUB-ASSEMBLY Click here

    OK

  29. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (ACTIVATE THE VSV FOR EGR CUT)


    1. Connect the intelligent tester to the DLC3.

    2. Start the engine and warm it up (engine coolant temperature is 70°C (158°F) or higher), and the A/C switch and all accessory switches should be off.

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

    4. Turn the tester on.

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

    6. Read the MAF value displayed on the tester when engine idling.

    7. Select the following menus: Powertrain / Engine and ECT / Active Test / Activate The VSV for EGR Cut.

    8. Read the MAF value when the VSV for EGR cut is turned from off to on using the Active Test function.

      Tech Tips


      • If idling continues for 15 minutes or more, the EGR valve opening angle target becomes 0% (EGR valve fully closed). As this makes diagnosis impossible, it becomes necessary to run the vehicle or to restart the engine.

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

      Result
      Active Test Result Proceed to

      Activate The VSV for EGR Cut:

      off (Open) to on (Close)

      		 MAF value is not changed A
      MAF value is changed B

      Note

      As the numerical values shown below may differ depending on the conditions such as the differences of measuring environments, and the changes of vehicle condition due to aging, do not determine with these values whether acceptable of not.

      Tech Tips

      The problem may be a temporary one, due to the entry of deposits or foreign matter. Please check that there are no deposits or foreign matter in the E-VRV or mass air flow meter.

      Reference
      EGR Valve Condition (Opening) MAF (Reference) Measuring Condition
      Open 3.0 to 9.0 gm/s

      • Atmosphere pressure: 101 kPa

      • Intake air temperature: 30°C (86°F)

      • Engine coolant temperature: 88°C (190°F)
      Close 15 to 22 gm/s

    B

    READ VALUE USING INTELLIGENT TESTER (MAF) Click here

    A

  30. READ VALUE USING INTELLIGENT TESTER (MAF)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester on.

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

    4. Read the value.

      Standard
      Tester Display Condition Specified Condition
      MAF Engine not running Below 0.3 gm/s

    NG

    REPLACE MASS AIR FLOW METER Click here

    OK

  31. REMOVE DEPOSIT (EGR VALVE ASSEMBLY)


    1. Remove the EGR valve assembly.

    2. Visually check the EGR valve assembly for deposits.

      If there are deposits, clean the EGR valve assembly.

      Tech Tips


      • If the EGR valve is stuck closed, the intake air amount increases and engine vibration may worsen.

      • If the EGR valve does not operate due to clogging or disconnection of the vacuum hose, repair the hose.

      • 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 EGR valve.

      • When cleaning the EGR valve assembly, use a piece of cloth soaked with non-residue solvent. Spraying the solvent directly onto these parts or soaking the parts in solvent may damage the parts.


    NEXT

  32. INSPECT EGR VALVE ASSEMBLY


    1. Inspect the EGR valve assembly Click here.


    OK

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

    NG

    REPLACE EGR VALVE ASSEMBLY Click here

  33. REPLACE EGR VALVE ASSEMBLY


    1. Replace the EGR valve assembly Click here.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  34. REPAIR OR REPLACE AIR INTAKE SYSTEM


    1. Repair or replace the malfunctioning part in the air intake system.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  35. REPLACE MASS AIR FLOW METER


    1. Replace the mass air flow meter.

      Tech Tips

      Before replacing the mass air flow meter, perform a wire harness inspection and if there are any problems with the wire harness, repair or replace it.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  36. REPLACE TURBOCHARGER SUB-ASSEMBLY


    1. Replace the turbocharger sub-assembly Click here.


    NEXT

  37. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    NEXT

    END

  38. READ VALUE USING INTELLIGENT TESTER (MAF)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester on.

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

    4. Read the value.

      Standard
      Tester Display Condition Specified Condition
      MAF Engine not running Below 0.3 gm/s

    NG

    REPLACE MASS AIR FLOW METER Click here

    OK

  39. CHECK EXHAUST MANIFOLD CONVERTER SUB-ASSEMBLY


    1. Remove the exhaust manifold converter sub-assembly.

    2. Visually check for catalyst clogging or carbon deposits adhering to the inner wall of the exhaust pipe upstream of the catalyst.

      OK
      Less than 10% of the cells are clogged.

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

    NG

    REPLACE EXHAUST MANIFOLD CONVERTER SUB-ASSEMBLY Click here

  40. REPLACE MASS AIR FLOW METER


    1. Replace the mass air flow meter.

      Tech Tips

      Before replacing the mass air flow meter, perform a wire harness inspection and if there are any problems with the wire harness, repair or replace it.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  41. REPLACE EXHAUST MANIFOLD CONVERTER SUB-ASSEMBLY


    1. Replace the exhaust manifold converter sub-assembly.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  42. CHECK FOR INTERMITTENT PROBLEMS


    1. Check for intermittent problems Click here.


    NEXT

  43. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    NEXT

    END

  44. COMPARE WITH SIMILAR VEHICLE WITH SAME ENGINE


    1. Confirm the situation in which the lack of power was experienced by the customer again, and compare the driving feeling under the same conditions using a similar vehicle with the same engine while collecting data with the intelligent tester.

      Tech Tips

      Confirm the state of the following conditions when the lack of power was experienced.


      • Accelerator pedal position (vehicle load)

      • Vehicle speed

      • Engine coolant temperature

      • Atmospheric temperature

      • Driving conditions before the lack of power occurred

      • Climate

      • Road and traffic conditions

      • When (what day) the problem was noticed

      • Whether the problem occurs suddenly or gradually

      • How often the problem occurs

      • Why the customer felt there is a lack of power (e.g. the customer compared their vehicle with another vehicle, somebody told the customer that their vehicle has a lack of power)

      • Level of lack of power (slight or drastic)

      Result
      Result Proceed to
      Significant difference is found A
      Significant difference is not found B

    A

    CHECK SNAPSHOT (MAP AND MAF) Click here

    B

  45. EXPLAIN THE INVESTIGATION RESULT TO CUSTOMER


    1. Vehicle performance is normal.

      There is no problem at this point in time. However, if the problem recurs, ask the customer to explain in detail the situation in which the problem occurred.

      The best course may be to have the customer ride in another vehicle with the same specifications to understand that there is no problem with the customer's vehicle.


    NEXT

    END