ECD SYSTEM Lack of Power or Hesitation

DESCRIPTION

Description
Malfunction Condition Main Trouble Area Related Trouble Area

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

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

  1. Fuel injector malfunctions


    • Fuel injector sliding malfunction

    • Fuel injector stuck closed

    • Fuel injector stuck open

    • Deposits in fuel injector

  2. Abnormal common rail pressure


    • Suction control valve

  3. Abnormal intake air volume


    • Turbocharger sub-assembly

    • Front exhaust pipe blockage

    • Exhaust manifold converter blockage

    • Diesel throttle does not open

    • EGR valve does not close

  4. Shift position switch malfunction

  • Intake air system leakage

  • Intake air system blockage

  • Fuel filter element is clogged

  • Fuel is not supplied to supply pump

  • Fuel injector compensation code

  • Mass air flow meter

  • Manifold absolute pressure sensor

  • EGR valve

  • Vehicle modifications

  • Glow (Poor acceleration when engine is cold)

  • Low quality fuel

  • Shift position switch

  • 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 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 of 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 a lack of engine power (e.g. the vehicle speed does not reach the target speed in the high speed range) while the vehicle is being driven.


  1. Faults and Symptoms of Common Rail Diesel Components


    1. Engine Control

      Mass Air Flow Meter
      Component 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
      Component 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.
      Turbocharger System
      Component 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
      Component 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
      Component 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
      Component Engine
      Main fault Damaged, seized up
      Symptoms Cannot crank, crank speed is low, strange noise
      Engine - 2
      Component 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


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

    2. Diesel Injection

      Fuel Supply Pump
      Component 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
      Component 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
      Component 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)).
      Pressure Discharge Valve
      Component Pressure discharge valve
      Main fault Does not completely close
      Symptoms Difficult to start, engine stall, rough idle, lack of power
      Injector Driver (EDU)
      Component 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
      Component 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
      Component Irregular fuel
      Main fault -
      Symptoms Difficult to start, rough idle (especially when cold)

    3. Diesel EGR

      EGR System
      Component 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


      • In cases when EGR Close Lrn. Status. is NG or EGR Close Lrn. Val. is out of the normal range (0.34 to 0.70 V), it is possible that the EGR valve cannot completely close.

    4. Diesel Throttle

      Diesel Throttle System
      Component 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

    Note

    The Data List values in the table are the results of checking one vehicle after warmed up. Only use these values for reference.


    1. Engine Control

      Engine Speed
      Data List Judgment of Data List Values Faulty Component Diagnosis Note
      Engine Speed Idling: 720 to 820 rpm Crankshaft position sensor When the crankshaft position sensor is malfunctioning, "Engine Speed" is approximately 0 or varies greatly from the actual engine speed.
      MAP
      Data List Judgment of Data List Values Faulty Component Diagnosis Note
      MAP

      MAP (inside intake air pressure)


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

      • With the ignition switch ON or vehicle idling, MAP is nearly equal to atmospheric pressure (standard atmospheric pressure = 101 kPa). Atmospheric pressure decreases 1 kPa each time altitude increases by 100 m, and is also affected by the current weather conditions. When the engine speed is about 1500 rpm or more, the turbocharger starts to take effect and MAP becomes higher than atmospheric pressure. The Data List item "Atmosphere Pressure" displays the output of the atmospheric pressure sensor.

      VN Turbo Command


      • 0%: Fully open vanes (drive rod contracts)

      • Over 90%: Fully closed vanes (drive rod expands)

      • Turbocharger fault

      • Diesel throttle does not open

      • Intake system blocked

      • Exhaust system blocked

      • Inspect while comparing with "Target Booster Pressure".

      • With the accelerator fully open, if the actual Manifold Absolute Pressure (MAP) is low compared to the target booster pressure by at least 20 kPa for 5 seconds or more, a feeling of insufficient power will occur.

      • When value of MAP is low Click here

      Results of real-vehicle check:


      • Ignition switch ON: 100 kPa

      • Cranking: 99 kPa

      • Idling (warm up the engine): 94 kPa (2 minutes after starting the vehicle)

      • Running without load (2500 rpm): 117 kPa

      • Running without load (4000 rpm): 138 kPa

      • Driving with the accelerator fully open at 2000 rpm: 186 kPa

      • Driving with the accelerator fully open at 3000 rpm: 242 kPa
      MAF
      Data List Judgment of Data List Values Faulty Component Diagnosis Note
      MAF -

      • MAF meter

      • MAF meter circuit

      • Intake system clogging, leaking

      • Exhaust system clogging

      • Turbocharger sub-assembly

      • Leaking or clogging of turbocharger passages

      • EGR valve does not close

      • Based on MAF, the ECM controls the fuel injection volume, injection timing, EGR, etc.

      • If the value is always approximately 0 g/sec.:


        • Mass air flow meter power source circuit is open.

        • VG circuit is open or shorted.

        • EVG circuit is open.

      Results of real-vehicle check:


      • Ignition switch ON: 0 g/sec.

      • Cranking: 5.07 g/sec.

      • Idling (warm up the engine): 3.87 g/sec. (2 minutes after starting the vehicle)

      • Running without load (2500 rpm): 34 g/sec.

      • Driving with the accelerator fully open at 2000 rpm: 79 g/sec.

      • Driving with the accelerator fully open at 3000 rpm: 138 g/sec.

      Tech Tips

      The maximum fuel injection volume is controlled according to the output from the mass air flow meter.
      Intake Air
      Data List Judgment of Data List Values Faulty Component Diagnosis Note
      Intake Air After a long soak, the engine coolant temperature, intake air temperature and ambient air temperature are approximately equal. Intake air temperature sensor If the value is -40°C (-40°F) or 140°C (284°F), the sensor circuit is open or shorted.
      Coolant Temp
      Data List Judgment of Data List Values Faulty Component Diagnosis Note
      Coolant Temp

      • Engine coolant temperature is approximately equal to intake air temperature after leaving overnight. After warm-up: Engine coolant temperature is 70°C (158°F) or higher.

      • In cases when the engine coolant temperature sensor output is obviously higher than the actual engine coolant temperature, when it is cold, there will be difficulty starting due to problems with glow plugs or insufficient fuel injection.

      • In cases when the engine coolant temperature sensor output is obviously lower than the actual engine coolant temperature, when it is warm, there will be difficulty starting (black smoke will also occur) due to an excess of injected fuel.

      		 Engine coolant temperature sensor If the value is -40°C (-40°F) or 140°C (284°F), the sensor circuit is open or shorted.

    2. Diesel Injection

      Target Common Rail Pressure
      Data List Judgment of Data List Values Faulty Component Diagnosis Note
      Target Common Rail Pressure - -

      • Inspect the (actual) fuel pressure, comparing it against the common rail target value.

      • Considered normal when the actual fuel pressure is within +/-5000 kPa of the target fuel pressure under stable conditions.

      Results of real-vehicle check:


      • Ignition switch ON: 35000 kPa

      • Cranking: 50000 kPa

      • Idling (warm up the engine): 35000 kPa (2 minutes after starting the vehicle)

      • Running without load (2500 rpm): 63240 kPa

      • Running without load (3500 rpm): 72950 kPa

      • Driving with the accelerator fully open at 2000 rpm: 138590 kPa

      • Driving with the accelerator fully open at 3000 rpm: 183210 kPa
      Fuel Press
      Data List Judgment of Data List Values Faulty Component Diagnosis Note
      Fuel Press

      • In a stable operating condition (e.g. idling), Fuel Press is Target Common Rail Pressure +/-5000 kPa.

      • When the Fuel Press is 20000 kPa below Target Common Rail Pressure, a lack of power will be felt.

      • When Fuel Press is below 25000 kPa, rough idling will occur.

      • If there is fuel supply pump (lack of discharge quantity) or pressure discharge valve (will not fully close) breakdown, the fuel pressure will drop. Also, a blocked fuel filter, leakage from fuel pipes, and an empty fuel tank will also make the fuel pressure drop.

      • When there is a fault with the fuel supply pump, there is a possibility of lack of power, starting trouble, engine stall, rough idle, etc.

      • Fuel Press is the actual common rail fuel pressure.

      • Inspect by comparing the fuel pressure with Target Fuel Pressure.

      • The ECM uses Fuel Press for feedback control of Target Fuel Pressure via the supply pump.

        The injection amount is determined based on the injection timing and fuel pressure.

        Also, the spray pattern is selected based on the fuel pressure.

      Results of real-vehicle check:


      • Ignition switch ON: 0 kPa

      • Cranking: 35390 kPa

      • Idling (warm up the engine): 33640 kPa

      • Running without load (2500 rpm): 62920 kPa

      • Driving with the accelerator fully open at 2000 rpm: 134390 kPa

      • Driving with the accelerator fully open at 3000 rpm: 178670 kPa
      Target Pump SCV Current
      Data List Judgment of Data List Values Faulty Component Diagnosis Note
      Target Pump SCV Current

      • Idling after warming up: around 923 to 1123 mA. When this value is large, the fuel supply pump is trying to increase the fuel discharge rate.

      • If the value becomes 3000 mA or higher, the suction control valve may become stuck.

      		 With this data, component fault not specified, use this data as a reference

      • ECU-calculated value for the suction control valve actuation target current.


      • Value is large when a high fuel pressure is desired.

      • When this deviates from the standard value, it indicates that for some reason, even though the pump is running hard, the actual fuel pressure is inconsistent with the target fuel pressure.

      Results of real-vehicle check:


      • Ignition switch ON: 1008 mA

      • Cranking: 1155 mA

      • Running without load (2500 rpm): 1300 mA

      • Driving with the accelerator fully open at 2000 rpm: 1233 mA

      • Driving with the accelerator fully open at 3000 rpm: 1397 mA
      Injection Feedback Val #1 (to #4)
      Data List Judgment of Data List Values Faulty Component Diagnosis Note
      Injection Feedback Val #1 (to #4)

      Injection Feedback Val:


      • When idling after the engine is warmed up, to make each cylinder engine speed equal, the fuel quantity of each fuel injector is corrected.

      • Cylinders more than 3 mm3/st may have a fault.

      Tech Tips

      Read the value after one minute of idling after warm up (engine coolant temperature above 70°C (158°F)). This value is only calculated when idling.

      • "Breakdown of injector or lack of compression" of a cylinder with an irregular Injection Feedback Val # value.

      • Do a compression Active Test. If there is a cylinder that is around 100 rpm more than the other cylinders, there is a possibility that that cylinder has a fault.

      • If all the cylinder speeds are even according to the compression Active Test result, consider the injector of the cylinder that has a fault.

      • With fuel injector faults, there is a possibility of rough idling, lack of power, difficulty starting, black smoke, white smoke and knocking.

      		 With Injection Feedback Val, find the malfunctioning cylinders. However, before replacing the injector, identify the malfunctioning cylinders with a power balance test.
      Injection Volume
      Data List Judgment of Data List Values Faulty Component Diagnosis Note
      Injection Volume

      • Diagnose the fuel injector faults from Injection Feedback Val # and Injection Volume at idling.

      • When Injection Volume is more than 10 mm3/st at idle with the engine warmed up and Injection Feedback Val # of all cylinders is less than 2.0 mm3/st, the following malfunctions are possible:

        - All cylinder fuel injectors are slightly blocked.

        - Fuel filter is blocked.

        - Poor quality fuel, increase in engine friction.

      		 All cylinders -

      Results of real-vehicle check:


      • Cranking: 22 mm3/st

      • Idling (warm up the engine): 5 mm3/st

      • Running without load (2500 rpm): 8 mm3/st

      • Running without load (4700 rpm): 16 mm3/st

      • Driving with the accelerator fully open at 2000 rpm: 75 mm3/st

      • Driving with the accelerator fully open at 3000 rpm: 78 mm3/st

    3. Diesel Throttle

      Actual Throttle Position
      Data List Judgment of Data List Values Faulty Component Diagnosis Note
      Actual Throttle Position

      • When the ignition switch is turned to ON (engine stopped), the diesel throttle is fully open, when the ignition switch is turned from ON to off, it will be fully closed temporarily.

      • During idling, the throttle is open partway.

      • When stuck closed (almost fully closed), there is a possibility of lack of power, rough idling, engine stall and black smoke.

      		 Throttle valve

      Actual Throttle Position is the closing percentage of the throttle valve.


      • Fully closed: 100%

      • Fully open: 0%

        Tech Tips

        There is no connection with the accelerator. However, under full load, the throttle is usually fully open (0%).

      Results of real-vehicle check:


      • Ignition switch ON: 0%

      • Cranking: 0%

      • Idling (warm up the engine): 93%

      • Running without load (2500 rpm): 51%

      • Driving with the accelerator fully open at 2000 rpm: 0%

      • Driving with the accelerator fully open at 3000 rpm: 0%

    4. Diesel EGR

      Target EGR Position
      Data List Judgment of Data List Values Faulty Component Diagnosis Note
      Target EGR Position - -

      • Fully open: 100%

      • Fully closed: 0%

      • Used for comparison to "Actual EGR Valve Pos".

      Results of real-vehicle check:


      • Ignition switch ON: 0%

      • Cranking: 0%

      • Idling (warm up the engine): 54%

      • Running without load (2500 rpm): 47%

      • Driving with the accelerator fully open at 2000 rpm: 0%

      • Driving with the accelerator fully open at 3000 rpm: 0%
      Actual EGR Valve Pos.
      Data List Judgment of Data List Values Faulty Component Diagnosis Note
      Actual EGR Valve Pos.

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

      The EGR valve Active Test can be used to check whether Actual EGR Valve Pos. = Target EGR Position (take into consideration the temperature of the intake air and the coolant temperature when the malfunction occurs).

      Sometimes the malfunction only occurs around a certain temperature. Take into consideration the temperature of the intake air and the coolant temperature when the malfunction occurs.

      		 EGR valve Inspect while comparing to "Target EGR Position".

      Results of real-vehicle check:


      • Ignition switch ON: 0%

      • Cranking: 0%

      • Idling (warm up the engine): 54%

      • Running without load (2500 rpm): 47%

      • Driving with the accelerator fully open at 2000 rpm: 0%

      • Driving with the accelerator fully open at 3000 rpm: 0%

  3. Examples of Actual Malfunctions

    Tech Tips


    • The purpose of the following examples is to help you to understand the relationship between each Data List item when a certain malfunction occurs. Understanding this relationship helps you to find the real root cause easier.

    • The following are examples of actual malfunctions of a common rail diesel engine.

    • Use them for reference when diagnosing malfunctions.

    • These are not data of the VERSO 2AD-FHV.


    1. Lack of power caused by overly low boost pressure

      A01IQMUE03

    2. Lack of power caused by overly low MAF

      A01IPWGE01

      In this example, the MAF (Mass Air Flow) value decreases greatly due to foreign matter being stuck to the MAF meter and causes a lack of power. The maximum fuel injection volume value is limited by the MAF value. As a result, there is a lack of power due to a lack of injection volume.

      In this case, even when the accelerator is fully open, the calculated load is low (Calculated Load = Injection Volume / Maximum Injection Volume at Current Engine Speed).

      Basically, the Manifold Absolute Pressure (MAP) is approximately equal to the Target Booster Pressure and this indicates that the turbocharger functions properly.

    3. EGR valve stuck in open position

      A01IOZCE01

      In this example, the EGR valve is stuck in the open position. Even with the accelerator pedal fully depressed, the EGR does not fully close and the MAF signal is low.

      Therefore, the fuel injection volume becomes limited and there is a lack of power. Jerking is also evident. At this time, even while accelerating with the accelerator fully open, the calculated load is low (Calculated Load = Current Injection Volume / Maximum Injection Volume at Current Engine Speed).

      Basically, the Manifold Absolute Pressure (MAP) is approximately equal to Target Booster Pressure and this indicates that the turbocharger functions properly.

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. 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.

  2. Trouble Area Chart According to Problem Cause

    A01IQT1E01
    A01IQ8DE02

    Note


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

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

    Tech Tips


    • Before troubleshooting, conduct the following:


      1. Check the fuel quality.

      2. Check the fuel for air.

      3. Check the fuel system for blockages.

      4. Check the air filter.

      5. Check the engine oil.

      6. Check the engine coolant.

      7. Check the engine idling speed and maximum engine speed.

PROCEDURE


  1. READ OUTPUT DTC (RELATED 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 Click here

    A

  2. TAKE SNAPSHOT DURING DRIVING TEST


    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 / Data List / All Data.

    4. A01IPZAE04

      Take a snapshot of the following Data List items with the intelligent tester.

      Tech Tips


      • Driving pattern for the test should be decided based on customer's comment regarding the situation in which the problem occurred.

      • 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 data in the illustration below is that of a normal vehicle, but as the data varies between individual vehicles, this data should only be used for reference.

      • Graphs like the ones shown below can be displayed by transferring the stored snapshot 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 fully open (obey all laws and regulations, and pay attention to driving conditions while driving the vehicle). Then, check the Data List with the engine warmed up and idling (the shift lever in neutral and A/C switch and all accessory switches off).

      A01IPOSE01
      A01INNNE01
      A01ITDAE01
      A01IU9SE01
      Reference Values with Engine Speed at 3500 rpm (Point A)
      Data List Value Unit
      Vehicle Speed 44 km/h
      Engine Speed 3500 rpm
      Accel Position 99.60 %
      Target Booster Pressure 234.19 kPa
      MAP 227 kPa
      MAF 140.96 g/sec.
      Calculate Load 100 %
      Target Common Rail Pressure 194350 kPa
      Fuel Press 189820 kPa
      Target Pump SCV Current 1402.8 mA
      Injection Volume 70.52

      mm3/st
      VN Turbo Command 44 %
      Actual EGR Valve Pos. 0 %
      Actual Throttle Position 0 %
      AF Lambda B1S1 1.167 -
      AFS Voltage B1S1 0.27 V
      Data Condition Idling (Engine warmed up)
      Data List Value Unit
      Engine Speed 771 rpm
      Target Booster Pressure 92.69 kPa
      MAP 94 kPa
      MAF 3.87 g/sec.
      Target Common Rail Pressure 35000 kPa
      Fuel Press 33640 kPa
      Injection Volume 5.15

      mm3/st
      VN Turbo Command 57 %
      Actual EGR Valve Pos. 54.1 %
      Target EGR Position 54.1 %
      Actual Throttle Position 93 %
      Accel Position 0.00 %
      Injection Feedback Val #1 0.0

      mm3/st
      Injection Feedback Val #2 -0.5

      mm3/st
      Injection Feedback Val #3 0.0

      mm3/st
      Injection Feedback Val #4 0.1

      mm3/st
      Atmosphere Pressure 100 kPa
      Coolant Temp 76 °C

      Tech Tips


      • 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.

    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

  3. CHECK SNAPSHOT


    1. A01IPZAE02

      Check the condition of the vehicle using the snapshot taken during the lack of power.

      Result
      Result Proceed to
      Fuel Press is less than "Target Common Rail Pressure - 20000 kPa" when accelerating with accelerator fully open B
      Target Pump SCV Current 3000 mA or more C

      One of the Injection Feedback Val #1 to 4 values is outside the range of +/-3 mm3/st when idling after warm up

      		 D

      Injection Feedback Val #1 to #4 is within the range of +/-3 mm3/st and Injection Volume is more than 10 mm3/st when idling after warm up

      		 E
      None of the above conditions apply A

    B

    BLEED AIR FROM FUEL SYSTEM Click here

    C

    CHECK HARNESS AND CONNECTOR (SUCTION CONTROL VALVE - ECM) Click here

    D

    INSPECT INJECTOR COMPENSATION CODE Click here

    E

    REPLACE FUEL INJECTORS OF ALL CYLINDERS Click here

    A

  4. CHECK SNAPSHOT


    1. A01IPZAE02

      Check the condition of the vehicle using the snapshot taken during the lack of power.

      Result
      Result Proceed to
      MAP is less than "Target Booster Pressure - 20 kPa" (MAF is normal) when accelerating with accelerator fully open A

      MAF is low when accelerating with accelerator fully open (MAP is normal)


      • 3000 rpm: 105 g/sec. or less

      • 3500 rpm: 125 g/sec. or less

      • 4000 rpm: 135 g/sec. or less

      Tech Tips

      If MAF (Mass Air Flow) decreases, Calculate Load will be 80% or less when accelerating with the accelerator fully open.

      		 B
      MAP and MAF are both low when accelerating with the accelerator fully open C
      None of the above conditions apply D

      Tech Tips

      When racing the engine, if the boost pressure becomes less than atmospheric pressure, there may be blockage in the intake system, or the turbocharger shaft may be stuck.


    B

    CHECK MASS AIR FLOW METER Click here

    C

    READ VALUE USING INTELLIGENT TESTER (ACCEL POSITION) Click here

    D

    READ VALUE USING INTELLIGENT TESTER (CATALYST DIFFERENTIAL PRESS) Click here

    A

  5. INSPECT VACUUM HOSE


    1. Check the vacuum hose connection (manifold absolute pressure sensor).

      OK
      Vacuum hose is connected securely.

    NG

    REPLACE VACUUM HOSE

    OK

  6. READ VALUE USING INTELLIGENT TESTER (MAP AND ATMOSPHERE 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 (engine stopped).

      Tech Tips


      • If MAP and Atmosphere Pressure have the same value, both are normal. If there is a difference of 10 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. Varies by weather (high atmospheric pressure, low atmospheric pressure).

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

    B

    REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR

    C

    READ VALUE USING INTELLIGENT TESTER (ACCEL POSITION) Click here

    A

    REPLACE ECM Click here

  7. CHECK MASS AIR FLOW METER


    1. Check the mass air flow meter Click here.


    NG

    REPLACE MASS AIR FLOW METER Click here

    OK

  8. CHECK EGR VALVE ASSEMBLY


    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 / EGR Close Lrn. Status.

    4. Read the values.

      Standard
      EGR Close Lrn. Status is OK

    5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position.

    6. When changing the Active Test continuously value to 0, 30, 60, 90, 60, 30 and 0%, check that Actual EGR Valve Pos. smoothly changes to the set opening angle.

      OK
      Value smoothly changes to set opening angle.

    7. Remove the EGR valve assembly Click here.

    8. Visually check the electric EGR control valve for deposits.

      If there are deposits, clean the electric EGR control valve.

      Note


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

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

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

    9. A01IRJNE01

      Hold the electric EGR control valve up to a light, and then from the side indicated by the arrow in the illustration, visually check that there is no gap between the valve and body.

      OK
      No light passes through (there is no gap between the valve and body).

      If light passes through (there is a gap between the valve and body), replace the electric EGR control valve assembly.

      Tech Tips

      Light passes through part A shown in the illustration even if the valve is completely closed. This is not a problem.


    NG

    REPLACE EGR VALVE ASSEMBLY Click here

    OK

  9. READ VALUE USING INTELLIGENT TESTER (ACCEL POSITION)


    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 / Accel Position.

    4. Read the value.

      Standard Value
      Condition Standard Value
      Accelerator pedal released 0%
      Accelerator pedal depressed 95% or more

      Accelerator pedal released → depressed

      Tech Tips

      Make sure the Accel Position opening angle changes smoothly.

      		 0 to 95% or more

    NG

    REPLACE ACCELERATOR PEDAL ROD ASSEMBLY Click here

    OK

  10. CHECK DIESEL THROTTLE BODY ASSEMBLY


    1. Check the diesel throttle body assembly Click here.


    NG

    REPLACE DIESEL THROTTLE BODY ASSEMBLY Click here

    OK

  11. 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 MALFUNCTIONING PARTS

    OK

  12. INSPECT TURBOCHARGER SUB-ASSEMBLY


    1. Inspect the turbocharger sub-assembly Click here.


    NG

    REPLACE TURBOCHARGER SUB-ASSEMBLY Click here

    OK

  13. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Check whether the lack of power has been successfully repaired.

      OK
      Malfunction has been repaired successfully.

      Tech Tips

      Symptoms may have appeared due to carbon deposits, etc.


    NG

    CHECK INTAKE SYSTEM DEPOSIT Click here

    OK

    END

  14. BLEED AIR FROM FUEL SYSTEM


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


    NEXT

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


    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 / Active Test / Test the Fuel Leak / Data List / Fuel Press, Target Common Rail Pressure, and Target Pump SCV Current.

    4. A01IPZAE02

      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.

      A01IN6JE06
      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" means target fuel pressure controlled by the ECM.

      • "Fuel Press" means actual fuel pressure.

      • 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.

      • If the pressure discharge valve mounted on the common rail is malfunctioning, the actual fuel pressure will change as indicated by "Pressure Discharge Valve Malfunctioning" in the illustration.

      Result
      Result Proceed to
      Difference between target fuel pressure and actual fuel pressure is less than 10000 kPa A
      Difference between target fuel pressure and actual fuel pressure is 10000 kPa or more B

    B

    INSPECT COMMON RAIL ASSEMBLY Click here

    A

    END

  16. INSPECT COMMON RAIL ASSEMBLY


    1. Inspect the common rail assembly Click here.


    OK

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

    NG

    REPLACE COMMON RAIL Click here

  17. CHECK HARNESS AND CONNECTOR (SUCTION CONTROL VALVE - ECM)


    1. A01INSDE06
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Suction Control Valve)
      *2

      Front view of wire harness connector

      (to ECM)

      Disconnect the suction control valve connector.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      C52-1 (+B) - C69-41 (PCV+) Always Below 1 Ω
      C52-2 (PCV) - C69-81 (PCV-) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      C52-1 (+B) or C69-41 (PCV+) - Body ground Always 10 kΩ or higher
      C52-2 (PCV) or C69-81 (PCV-) - Body ground Always 10 kΩ or higher

    4. Reconnect the suction control valve connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  18. 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 lack of fuel, fuel pressure drops.

      • Inspect for fuel filter clogging.

        (Check that the fuel filter is not clogged)


    NG

    CHECK AND REPLACE CLOGGED FUEL PIPE (INCLUDING FUEL FREEZING) (FUEL TANK - FUEL SUPPLY PUMP) Click here

    OK

  19. REPLACE SUCTION CONTROL VALVE


    1. Replace the suction control valve Click here.


    NEXT

  20. BLEED AIR FROM FUEL SYSTEM


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


    NEXT

  21. PERFORM FUEL SUPPLY PUMP INITIALIZATION


    1. Perform fuel supply pump initialization Click here.


    NEXT

  22. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Check whether the lack of power has been successfully repaired.

      Tech Tips

      Fuel Press is within +/-5000 kPa of Target Common Rail Pressure.


    NEXT

    END

  23. READ VALUE USING INTELLIGENT TESTER (CATALYST DIFFERENTIAL PRESS)


    1. Connect the intelligent tester to the DLC3.

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

    3. Start the engine and drive the vehicle until the engine coolant temperature reaches 60°C (140°F) or higher.

    4. Enter the following menus: Powertrain / Engine and ECT / Data List / Catalyst Differential Press.

    5. Check the differential pressure at an engine speed of 3000 rpm with no load.

      Standard
      Catalyst Differential Press is less than 0.25

    6. With the vehicle stopped, fully depress the accelerator pedal for 5 seconds and then release it.*A

    7. Repeat procedure *A 10 times.*B

    8. Check for black smoke emission during the above procedures *A and *B.

      Standard
      Black smoke is emitted less than 5 times.

      Tech Tips

      Even if the black smoke is very thin, count the black smoke emission if there is any visible smoke.

      Result
      Differential Pressure (kPa) Proceed to Note

      Catalyst Differential Press 0.25 or more

      at 3000 rpm (No engine load)

      		 B An extremely large amount of PM (Particulate Matter) has accumulated in the DPNR catalyst.
      Black smoke is emitted 5 times or more B

      The DPNR catalyst cannot trap PM because it is melted or cracked, and therefore must be replaced.

      Also, if a piece of the catalyst breaks off, due to melting or another condition, and enters the exhaust pipe downstream, the exhaust pipe could be blocked, possibly causing a different malfunction.

      Therefore, when replacing the DPNR catalyst, visually inspect the rear surface of the DPNR filter substrate to determine if replacement of the exhaust pipe is necessary.
      Except above A -

      Tech Tips


      • If the "Catalyst Differential Press" is more than about 0.4, DTC P2002 (Particulate Trap Efficiency Below Threshold [Bank 1]) will be stored.

      • The standard for the differential pressure sensor output is as follows:

        Reference
        Condition Differential Pressure Output
        Ignition switch ON Approximately 0 kPa

      • If the Differential Pressure output is always 3 kPa, an open or short may exist in the differential pressure sensor circuit.

      • If the Differential Pressure outputs a negative value when the engine is maintained at an engine speed of 3000 rpm with no load, the hose and pipe connections may be incorrect.


    B

    REPLACE MONOLITHIC CONVERTER ASSEMBLY Click here

    A

  24. CHECK TEMPERATURE WHEN LACK OF POWER OCCURS


    1. Check the temperature when the lack of power occurs.

      Result
      Result Proceed to
      Poor acceleration only when engine is cold A
      Poor acceleration when engine is cold and warm B

    B

    INSPECT INJECTOR COMPENSATION CODE Click here

    A

  25. INSPECT ENGINE COOLANT TEMPERATURE SENSOR


    1. Inspect the engine coolant temperature sensor Click here.

      Tech Tips

      After warming up the engine, the engine coolant temperature should be 70°C (158°F) or more. After leaving the vehicle overnight, the engine coolant temperature should be nearly equal to the intake air temperature.


    NG

    REPLACE ENGINE COOLANT TEMPERATURE SENSOR Click here

    OK

  26. INSPECT GLOW PLUG ASSEMBLY (RESISTANCE)


    1. Inspect the glow plug assembly Click here.


    NG

    REPLACE GLOW PLUG ASSEMBLY Click here

    OK

  27. INSPECT INJECTOR COMPENSATION CODE


    1. Read the injector compensation codes Click here.

      OK
      Compensation codes stored in the ECM match the compensation codes of the installed fuel injectors.

    NG

    REGISTER INJECTOR COMPENSATION CODE AND PERFORM PILOT QUANTITY LEARNING Click here

    OK

  28. CHECK FUEL QUALITY


    1. Check that fuel with a low cetane number is used.


    NEXT

  29. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Check whether the lack of power has been successfully repaired by starting the engine.


    NEXT

    END

  30. INSPECT INJECTOR COMPENSATION CODE


    1. Read the injector compensation codes Click here.

      OK
      Compensation codes stored in the ECM match the compensation codes of the installed fuel injectors.

    NG

    REGISTER INJECTOR COMPENSATION CODE AND PERFORM PILOT QUANTITY LEARNING Click here

    OK

  31. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE CYLINDER #1 TO #4 FUEL CUT)

    Tech Tips

    Use this Active Test to determine the malfunctioning cylinder.


    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 / Control the Cylinder #1 to #4 Fuel Cut.

      Tech Tips


      • If the engine idle speed does not change when a fuel injector 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.


    NEXT

  32. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CHECK THE CYLINDER COMPRESSION)

    Tech Tips

    Use this Active Test to help determine whether a cylinder has compression loss or not.


    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 / Active Test / Check the Cylinder Compression / Data List / Compression / Engine Speed of Cyl #1 to #4.

    4. Check the engine speed during the Active Test.

      OK
      The values of Engine Speed Cyl #1 to #4 are within +/-10 rpm of each other.

      Tech Tips

      When cranking, if the speed of a cylinder is approximately 100 rpm more than the other cylinders, there is probably a loss of compression in that cylinder.


    OK

    REPLACE FUEL INJECTOR OF MALFUNCTIONING CYLINDER Click here

    NG

    CHECK CYLINDER COMPRESSION PRESSURE OF MALFUNCTIONING CYLINDER Click here

  33. CHECK CYLINDER COMPRESSION PRESSURE OF MALFUNCTIONING CYLINDER

    Tech Tips

    Measure the compression of the cylinder that had a high speed during the Active Test "Check the Cylinder Compression".


    1. Check the cylinder compression pressure Click here.


    NG

    CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

    OK

  34. REPLACE FUEL INJECTOR OF MALFUNCTIONING CYLINDER

    Tech Tips

    The injector is determined to be faulty as the corresponding cylinder is malfunctioning, but has no compression loss.


    1. Replace the fuel injector of the malfunctioning cylinder Click here.


    NEXT

  35. BLEED AIR FROM FUEL SYSTEM


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


    NEXT

  36. 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

  37. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    NEXT

    END

  38. CHECK INTAKE SYSTEM DEPOSIT


    1. Check carbon is accumulating on the intake manifold, cylinder head, etc. and if so, clean it off.


    NEXT

  39. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

    Tech Tips

    Symptoms may have appeared due to carbon deposits, etc.


    NEXT

    END

  40. REPLACE FUEL INJECTORS OF ALL CYLINDERS


    1. Replace the fuel injectors Click here.


    NEXT

  41. BLEED AIR FROM FUEL SYSTEM


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


    NEXT

  42. REGISTER INJECTOR COMPENSATION CODE AND PERFORM PILOT QUANTITY LEARNING


    1. Register the injector compensation codes Click here.

    2. Perform registration of the fuel injector pilot quantity learning values Click here.


    NEXT

  43. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    NEXT

    END

  44. CHECK AND REPLACE CLOGGED FUEL PIPE (INCLUDING FUEL FREEZING) (FUEL TANK - FUEL SUPPLY PUMP)


    1. Check and replace clogged the fuel pipe.


    NEXT

  45. BLEED AIR FROM FUEL SYSTEM


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


    NEXT

  46. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    NEXT

    END

  47. REPLACE COMMON RAIL


    1. Replace the common rail Click here.


    NEXT

  48. BLEED AIR FROM FUEL SYSTEM


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


    NEXT

  49. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    NEXT

    END

  50. 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 Click here

    B

  51. 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