Ecd System (W/ Egr Cooler) Rough Idling Or Excessive Engine Vibrations

DESCRIPTION

INSPECTION PROCEDURE

CHECK MALFUNCTION CONDITION

CHECK WIRE HARNESS AND CONNECTION IN ENGINE COMPARTMENT

READ OUTPUT DTC (RELATING TO ENGINE)

TAKE SNAPSHOT DURING IDLING (PROCEDURE 4)

CHECK WHITE SMOKE

CHECK DATA LIST (ENGINE SPEED)

CHECK DATA LIST (INJECTION FEEDBACK VAL #1 TO #4 AND INJECTION VOLUME)

INSPECT INJECTOR COMPENSATION CODE

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

REPLACE INJECTOR ASSEMBLY OF MALFUNCTIONING CYLINDER

CLEAN FUEL FILTER CASE AND REPLACE FUEL FILTER

BLEED AIR FROM FUEL SYSTEM

REGISTER INJECTOR COMPENSATION CODE AND PERFORM PILOT QUANTITY LEARNING

REPAIR OR REPLACE HARNESS AND CONNECTOR

CHECK AND REPAIR ENGINE ASSEMBLY

CHECK AIR CONDITIONING SYSTEM

CHECK DATA LIST (FUEL PRESS AND TARGET COMMON RAIL PRESSURE)

INSPECT CLOGGED FUEL PIPE

REPLACE FUEL SUPPLY PUMP ASSEMBLY (SUCTION CONTROL VALVE)

BLEED AIR FROM FUEL SYSTEM

PERFORM FUEL SUPPLY PUMP INITIALIZATION

REPAIR OR REPLACE CLOGGED FUEL LINE

BLEED AIR FROM FUEL SYSTEM

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (ACTIVATE THE EGR VALVE CLOSE)

REMOVE DEPOSIT (ELECTRIC EGR CONTROL VALVE ASSEMBLY)

CHECK AND REPLACE ENGINE MOUNTING INSULATOR

CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

DESCRIPTION

HINT:

1. This troubleshooting procedure checks for the cause of rough idling and excessive engine vibrations.
   
2. 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.
   
3. Check that the vehicle has not been modified in any way prior to the vehicle inspection.
   

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
   HINT: The maximum fuel injection volume is controlled according to the output from the mass air flow meter.

   
   

   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		Measure the resistance of the glow plug

   
   

   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

   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 Fuel Press is within 5000 kPa of Target Common Rail Pressure during idling with the engine warmed up (engine coolant temperature is higher than 70°C (158°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. HINT: The fuel pressure changes at engine start, but is approx. 25000 kPa at engine start after the engine is warmed up. When Target Pump SCV Current is 3000 mA or higher, the suction control valve has a tendency to become stuck.
   Diagnostic Trouble Code		Even if Fuel Press is below 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 Fuel Press is within 5000 kPa of Target Common Rail Pressure during idling with the engine warmed up (engine coolant temperature is higher than 70°C (158°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. HINT: 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 Fuel Press 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.

   
   

   Injector Driver

   Main fault		Circuit fault: The fuel injector assembly does not open.
   Symptoms		Difficult to start, rough idle, lack of power, black smoke, white smoke, knocking
   Data List		Same as injector assembly
   Diagnostic Trouble Code		When the injector driver 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 Slowly raise the engine speed from idling to 3000 rpm with the vehicle stopped and check that Fuel Press and Common Rail Pres Sens 2 follow Target Common Rail Pressure. If the fuel pressure sensor malfunctions, the actual fuel pressure may deviate from the target fuel pressure (either Fuel Press or Common Rail Pres Sens 2 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 Position Generally, Actual EGR Valve Pos. = Target EGR Position +/-5% (fully closed: 0%, fully open: 100%). Using the 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 turned to ON (engine stopped). EGR valve opens to the halfway point at idling after the engine is warmed up.

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 0%: Fully open 100%: Fully closed When the ignition switch is ON (the engine is 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 fully closed temporarily.

1. Engine Speed
   
2. MAF
   
3. Intake Air
   
4. Coolant Temp
   
5. Engine Speed of Cyl #1 (to #4)
   
6. Target Common Rail Pressure
   
7. Fuel Press
   
8. Target Pump SCV Current
   
9. Injection Feedback Val #1 (to #4)
   
10. Injection Volume
    
11. Actual Throttle Position
    
12. Target EGR Position
    
13. Actual EGR Valve Pos.
    
14. EGR Close Lrn. Status
    

INSPECTION PROCEDURE

NOTICE:

1. After replacing the ECM, the new ECM needs registration (HILUX_TGN26 RM0000012XK05BX.html) and initialization (HILUX_TGN26 RM000000TIN04CX.html).
   
2. After replacing the fuel supply pump, the ECM needs initialization (HILUX_TGN26 RM000000TIN04CX.html).
   
3. After replacing an injector assembly, the ECM needs registration (HILUX_TGN26 RM0000012XK05BX.html).
   

1. Identify when shuddering occurs.
   
   

   Result

   Result	Proceed to
   When idling	A
   When engaging engine clutch at vehicle start	B (Clutch system shudders)

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

   OK:

   The wire harnesses and connectors are connected securely.
   

   HINT:

   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.

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.
   

1. Connect the intelligent tester to the DLC3.
   

2. Start the engine and turn the tester on.
   

3. Warm up the engine (engine coolant temperature is 70°C (158°F) or higher).
   

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

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

   Text in Illustration

   *1	Snapshot Button

   HINT:

   1. A snapshot can be used to compare vehicle data from the time of the malfunction to normal data and is very useful for troubleshooting.
      
   2. Graphs can be displayed by transferring the stored snapshot data from the tester to a PC. Intelligent Viewer must be installed on the PC.
      
   3. The shift lever should be in neutral and the A/C switch and all accessory switches should be off.
      
   4. If rough idling occurs when the A/C switch is on, take another snapshot with the A/C switch on.
      
   5. 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.
      

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.
   

   NOTICE:

   Be sure not to check for white smoke indoors.

   HINT:

   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 like burning oil.

   
   

   Result

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

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

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

   Result

   Result	Proceed to
   Injection Feedback Val for at least one cylinder is more than +3 mm3/st and engine vibration is abnormally large	A
   Except above	B

   HINT:

   1. 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.
      
   2. 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.
      

1. Read the injector compensation code (HILUX_TGN26 RM0000012XK05BX_02_0006.html).
   

   OK:

   Compensation codes stored in the ECM match compensation codes of the installed injector assemblies.
   

HINT:

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.
   

   HINT:

   1. If the engine idle speed does not change when an injector assembly is disabled, the cylinder being tested is malfunctioning.
      
   2. 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.
      

1. Replace the injector assembly of the malfunctioning cylinder (HILUX_TGN26 RM000002SY1021X.html).
   

   NOTICE:

   1. When replacing the injector assembly for a cylinder, always be sure to use a new injection pipe.
      
   2. Follow the procedure in the repair manual and temporarily install the injection pipes and nozzle leakage pipe, and then correctly position the injector assemblies. After that, tighten parts according to the torque specifications.
      
   3. 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.
      
   4. If an injector assembly deteriorates and malfunctions, other problems such as knocking, rough idle, etc. may occur.
      
   5. If an injector assembly becomes out of position, it is possible that the seal between the injector assembly and injection pipe may become incomplete, resulting in a fuel leak.
      

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

   HINT:

   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.

1. Bleed the air from the fuel system (HILUX_TGN26 RM000002SY8025X_01_0002.html).
   

1. Register the injector compensation code (HILUX_TGN26 RM0000012XK05BX_02_0003.html).
   

2. Perform the injector pilot quantity learning (HILUX_TGN26 RM0000012XK05BX_02_0009.html).
   

1. Repair or replace the harness or connector.
   

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

   1. Check cylinder compression pressure (HILUX_TGN26 RM00000147301IX_01_0002.html).
      

1. Check the air conditioning system.
   

   HINT:

   1. Be sure to check the air conditioning hoses and pipes.
      
   2. Check the refrigerant pressure (HILUX_TGN26 RM000001R8Z02GX_01_0001.html).
      

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 Fuel Press and Target Common Rail Pressure is 5000 kPa (51.0 kgf/cm2, 725 psi) or more	A
   Except above	B

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 / Diesel Injection.
   

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 Fuel Press value.
   

   
   
   
   
   

   Result

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

   NOTICE:

   1. *1: The cause may be a squashed or blocked fuel pipe or hose.
      
   2. *2: The cause may be a clogged fuel filter.
      

1. Replace the fuel supply pump assembly (HILUX_TGN26 RM0000014FO01RX.html).
   

1. Bleed the air from the fuel system (HILUX_TGN26 RM000002SY8025X_01_0002.html).
   

1. Perform fuel supply pump initialization (HILUX_TGN26 RM000000TIN04CX.html).
   

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

2. Replace the fuel filter element sub-assembly.
   

   HINT:

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

1. Bleed the air from the fuel system (HILUX_TGN26 RM000002SY8025X_01_0002.html).
   

1. Connect the intelligent tester 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 ignition switch off. Wait for 30 seconds, and then restart the engine.
   

4. Turn the tester on.
   

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

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

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

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

   HINT:

   1. If idling continues for 15 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.
      
   2. Before performing the diagnosis, confirm that the EGR valve target opening angle is not 0%.
      
   3. When "Coolant Temp" is 75°C (167°F) or higher during idling, the exhaust gas flows through the EGR cooler. If MAF does not change when the EGR is cut even though the EGR valve is operating normally, the EGR cooler may be clogged.
      
   4. When idling while warming up the engine, the actuator operates and the EGR cooler is bypassed. However, if the connector of the VSV for the EGR cooler is disconnected, the EGR cooler is not bypassed and it is possible to check how clogged the EGR cooler is.
      
   
   

   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

   NOTICE:

   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.

   HINT:

   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 vacuum regulating valve assembly or mass air flow meter.

   
   

   Reference:

   
   

   EGR Valve Condition (Opening)	Measuring Condition	MAF (Reference)
   Open (55%)	Atmosphere pressure: 101 kPa Intake air temperature: 30°C (86°F) Engine coolant temperature: 88°C (190°F)	3.0 to 9.0 gm/s
   Closed (0%)		15 to 22 gm/s

1. Remove the electric EGR control valve assembly (HILUX_TGN26 RM000002RK9023X.html).
   

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

   HINT:

   1. 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.
      
   2. If the EGR valve does not operate due to clogging or disconnection of the vacuum hose, repair the hose.
      
   3. 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.
      
   4. When cleaning the electric vacuum regulating 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.
      

3. Reinstall the electric EGR control valve assembly (HILUX_TGN26 RM000002RK6023X.html).
   

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.