ECD SYSTEM > Rough Idling or Excessive Engine Vibrations

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DESCRIPTION

HINT:

1. Rough idling and excessive engine vibrations are checked in this troubleshooting procedure.
   
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 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.
   
3. Check that the vehicle has not been modified in any way prior to the vehicle inspection.
   

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

   
   

   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 

   Component		Engine
   Main fault		Loss of compression
   Symptoms		Rough idle (lack of power always)
   Data List		Engine Speed of Cyl The engine is cranked for approximately 10 seconds, then the speed of each cylinder is measured (compression test). Indicates the speed of each cylinder when cranking. Example - Normal: Engine speed of all cylinders is approximately equal. When No. 1 cylinder compression is extremely low, "Engine speed of Cyl #1" is approximately 300 rpm, and "Engine speed of Cyl #2 to #4" is approximately 200 rpm. Usually the tester displays the value of when the engine is started. Injection Feedback Val "Injection Feedback Val" more than 2.0 mm3/st: Injector breakdown is causing injection volume deviation, or insufficient compression is causing poor combustion.

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 When in a stable condition such as when idling, the fuel pressure is within +/-10000 kPa of the target fuel 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. HINT: 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 1530 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 may 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 When in a stable condition such as when idling, the fuel pressure is within +/-10000 kPa of the target fuel 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. HINT: 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 may not be stored.

   
   

   Fuel Injector 

   Component		Fuel injector
   Main fault		Injection hole blockage Nozzle needle or valve piston does not move smoothly
   Symptoms		Rough idle, lack of power, black smoke, white smoke, knocking
   Data List		Injection Feedback Val "Injection Feedback Val" more than 2.0 mm3/st: Injector breakdown is causing injection volume deviation, or insufficient compression is causing poor combustion.

   
   

   Pressure Control Valve 

   Component		Pressure control valve
   Main fault		Does not completely close
   Symptoms		Difficult to start, engine stall, rough idle, lack of power

   
   

   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 Slowly raise the engine speed from idling to 3000 rpm with the vehicle stopped, and check that Fuel Press follows Target Common Rail Pressure. If the fuel pressure sensor malfunctions, the actual fuel pressure may deviate from the target fuel pressure. (However, the value may not deviate even when a malfunction is present).
   Diagnostic Trouble 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 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 Pos. 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 Pos. (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 warmed up.

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, Target Throttle Position 0%: Fully open 100%: Fully closed If there is a malfunction of the throttle actuator, compare the target and actual throttle position values for the troubleshooting.

HINT:

The Data List values in the table are the results of checking one vehicle under a specific condition (engine coolant temperature, intake air temperature, atmosphere pressure etc.). Therefore, use these values for reference only.

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 Crankshaft position sensor circuit	When the crankshaft position sensor is malfunctioning, "Engine Speed" is approximately 0 or varies greatly from the actual engine speed.

   
   

   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 the MAF, the ECM controls the fuel injection volume, injection timing, EGR, etc. If the value is always approximately 0 gm/sec.: Mass air flow meter power source circuit is open. VG circuit is open or shorted. If the value is always 200 gm/sec. or more: EVG circuit is open.
   	Results of real-vehicle check: Ignition switch ON: 0 gm/sec. Cranking (295 rpm): 2.72 gm/sec. Idling (warm up the engine): 5.0 gm/sec. (2 minutes after starting the vehicle and "Actual EGR Valve Pos." = 56%) Idling (warm up the engine): 8.5 gm/sec. (2 minutes after starting the vehicle and "Actual EGR Valve Pos." = 0.3%) Running without load (2500 rpm): 21.2 gm/sec. (at "Actual EGR Valve Pos." = 56%) Running without load (4500 rpm): 69.8 gm/sec. Driving with the accelerator fully open at 2000 rpm: 43.94 gm/sec. Driving with the accelerator fully open at 3000 rpm: 72.47 gm/sec. Driving with the accelerator fully open at 4500 rpm: 87.8 gm/sec.
   	HINT: The maximum fuel injection volume is controlled according to the output from the mass air flow meter. If the time of engine idling is long (approximately 20 minutes or more), EGR will be cut off. At this time, if the vehicle is driven in 5th gear at 70 km/h for 10 minutes, EGR resumes.

   
   

   Intake Air 

   Data List	Judgment of Data List Values	Faulty Component	Diagnosis Note
   Intake Air	-	Intake air temperature sensor.	After a long soak, the engine coolant temperature, intake air temperature and ambient air temperature are approximately equal. 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 a long soak. After warm-up: Engine coolant temperature is 75°C (167°F) or more. In cases when the engine coolant temperature 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 -30°C (-22°F) or 120°C (248°F), the sensor circuit is open or shorted. After a long soak, the Coolant Temp, Intake Air and ambient air temperature are approximately equal.

   
   

   Engine Speed of Cyl #1 (to #4) 

   Data List	Judgment of Data List Values	Faulty Component	Diagnosis Note
   Engine Speed of Cyl #1 (to #4)	When cranking, the engine speed of each cylinder is the same under normal conditions. When a cylinder is approximately 100 rpm higher than the other cylinders, it is conceivable that the compression of that cylinder is being lost. HINT: Usually the tester displays the value of when the engine is started.	-	The engine is cranked for approximately 10 seconds, then the speed of each cylinder is measured (compression test). Indicates the speed of each cylinder when cranking. Example - Normal: Engine speed of all cylinders is approximately equal. When No. 1 cylinder compression is extremely low, "Engine speed of Cyl #1" is approximately 300 rpm, and "Engine speed of Cyl #2 to #4" is approximately 200 rpm.

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 +/-10000 kPa of the target fuel pressure under stable conditions.
   	Results of real-vehicle check: Ignition switch ON: 25000 kPa Cranking: 21470 kPa Idling (warm up the engine): 25000 kPa (2 minutes after starting the vehicle) Running without load (2500 rpm): 35590 kPa Running without load (3500 rpm): 80200 kPa Running without load (4500 rpm): 68200 kPa Driving with the accelerator fully open at 2000 rpm: 114330 kPa Driving with the accelerator fully open at 3000 rpm: 156460 kPa Driving with the accelerator fully open at 4500 rpm: 160000 kPa

   
   

   Fuel Press 

   Data List	Judgment of Data List Values	Faulty Component	Diagnosis Note
   Fuel Press	Idling: 19900 to 37000 kPa 4000 rpm: 50700 to 73000 kPa Fuel Press = Target Common Rail Pressure +/-10000 kPa at stable condition During cranking, if Fuel Press is lower than 25000 kPa, there may be difficulty starting (take care as there is a response lag when the pressure rises). When Fuel Press is lower than 25000 kPa, rough idling will occur.	If there is a fault with the fuel supply pump (lack of discharge quantity) or pressure control valve (will not fully close), the fuel pressure will drop. Also, a blocked fuel filter, leakage from fuel pipes, and lack of fuel will also make the fuel pressure drop. If air mixes with the fuel, the fuel pressure will shift away from the target fuel pressure. When there is a fault with the fuel supply pump, there is a possibility of lack of power, engine stall, rough idle and difficulty starting.	Fuel pressure is the actual common rail fuel pressure. Inspect by comparing the fuel pressure with the target fuel pressure. When in a stable condition such as when idling, the fuel pressure is within +/-10000 kPa of the target fuel pressure. The ECM uses fuel pressure for feedback control of the target fuel pressure via the supply pump. The injection amount is determined based on the injection timing and fuel pressure.
   	Results of real-vehicle check: Ignition switch ON: 140 kPa Cranking: 21920 kPa Idling (warm up the engine): 25430 kPa (2 minutes after starting the vehicle) Running without load (2500 rpm): 35550 kPa Running without load (4500 rpm): 68990 kPa Driving with the accelerator fully open at 2000 rpm: 114950 kPa Driving with the accelerator fully open at 3000 rpm: 154320 kPa Driving with the accelerator fully open at 4500 rpm: 160280 kPa

   
   

   Target Pump SCV Current 

   Data List	Judgment of Data List Values	Faulty Component	Diagnosis Note
   Target Pump SCV Current	1530 mA or less	Suction control valve malfunction Clogged fuel filter	ECU-calculated value for the suction control valve actuation target current. Value is large when a high fuel pressure is desired. Value becomes stuck at 1800 mA or more or operation is poor (poor movement due to deposits, etc.). 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: Cranking: 1052 mA Idling: 1167 mA Running without load (2500 rpm): 1300 mA Running without load (4500 rpm): 1188 mA Driving with the accelerator fully open at 2000 rpm: 1102 mA Driving with the accelerator fully open at 3000 rpm: 934 mA Driving with the accelerator fully open at 4500 rpm: 920 mA

   
   

   Injection Feedback Val #1 (to #4) 

   Data List	Judgment of Data List Values	Faulty Component	Diagnosis Note
   Injection Feedback Val #1 (to #4)	When idling after the engine is warmed up, the fuel quantity of each injector is corrected to make each cylinder engine speed equal. Cylinders more than 2 mm3/st may have a fault. HINT: Read the value after one minute of idling after warm up (engine coolant temperature above 75°C (167°F)). This value is only calculated when idling.	Injector clogging Injector deterioration Decrease in cylinder compression Injector compensation code is incorrectly set (forgot to input code after replacement or made mistake during setting of code after replacing ECM with one from another vehicle) With injector faults, other than difficulty starting, there is a possibility of rough idling, lack of power, black smoke, white smoke and knocking.	When idling after warm up, the injection amount for each cylinder is corrected to optimize the difference between the engine speed of each cylinder. Example: For cylinders that are slowing the engine speed compared to other cylinders, the injection volume is increased. "Injection Feedback Val" more than 2.0 mm3/st: Injector breakdown is causing injection volume deviation, or insufficient compression is causing poor combustion.

   
   

   Injection Volume 

   Data List	Judgment of Data List Values	Faulty Component	Diagnosis Note
   Injection Volume	-	-	If injectors are clogged, fuel quality is poor, the fuel filter is clogged, or engine friction increases, then "Injection Volume" will increase.
   	Results of real-vehicle check: Cranking: 19.58 mm3/st Idling (warm up the engine): 4.19 mm3/st (at "Actual EGR Valve Pos." = 0.3%) Idling (warm up the engine): 4.58 mm3/st (at "Actual EGR Valve Pos." = 56%) Running without load (2500 rpm): 4.68 mm3/st Running without load (4500 rpm): 8.28 mm3/st Driving in 3rd gear 60 km/h (37 mph): 9.39 mm3/st Driving in 3rd gear 60 km/h (37 mph) during PM regeneration: 26.28 mm3/st Driving with the accelerator fully open at 2000 rpm: 36.48 mm3/st Driving with the accelerator fully open at 3000 rpm: 46.97 mm3/st Driving with the accelerator fully open at 4500 rpm: 37.89 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, the diesel throttle is fully closed temporarily. With the diesel throttle stuck almost fully closed, there is a possibility of rough idling, engine stall, black smoke, difficulty starting and lack of power.	Diesel throttle body	Closing percentage of the throttle valve. Fully closed: 100% Fully open: 0% If there is a malfunction of the throttle actuator, compare the target and actual throttle position values for the troubleshooting.
   	Results of real-vehicle check: Ignition switch ON: -1% Cranking: -1% Idling (warm up the engine): -1% Running without load (2500 rpm): 0% Running without load (4500 rpm): 0% Driving in 3rd gear 60 km/h (37 mph): -1% Driving in 3rd gear 60 km/h (37 mph) during PM regeneration: 78% Driving with the accelerator fully open at 2000 rpm: 0% Driving with the accelerator fully open at 4500 rpm: 0% Soon after engine running to ignition switch off: 0% → 99% → 0%

   
   

   Throttle Motor Duty 

   Data List	Judgment of Data List Values	Faulty Component	Diagnosis Note
   Throttle Motor Duty	-	-	When the value of the Throttle Motor Duty increases, the moving force to open and close the diesel throttle valve increases.
   	Results of real-vehicle check: Cranking: 16.4% Idling (warm up the engine): 9.4% Running without load (2500 rpm): 10.1% Running without load (4500 rpm): 10.5% Driving with the accelerator fully open at 2000 rpm: 12.5% Driving with the accelerator fully open at 3000 rpm: 12.1% Throttle valve closing when soon after engine running to ignition switch off: 79.6%

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". HINT: If the time of engine idling is long (approximately 20 minutes or more), EGR will be cut off. At this time, if the vehicle is driven in 5th gear at 70 km/h for 10 minutes, EGR resumes.
   	Results of real-vehicle check: Ignition switch ON: 0% Cranking: 0% Idling with EGR off (warm up the engine): 0.3% Idling with EGR on (warm up the engine): 56% Running without load (2500 rpm): 57% Running without load (4500 rpm): 0% Driving with the accelerator fully open at 2000 rpm: 0% Driving with the accelerator fully open at 3000 rpm: 0% Driving with the accelerator fully open at 4500 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 (Fully closed = 0%, Fully open = 100%) The EGR valve Active Test can be used to check whether the Actual EGR Valve Pos. = Target EGR Position	EGR valve assembly	Fully open: 100% Fully closed: 0% Inspect while comparing to "Target EGR Position". Check the valve movement via the Active Test. Sometimes the malfunction only occurs around a certain temperature, so refer to the engine coolant temperature and outside temperature at the time the malfunction occurred. HINT: If the time of engine idling is long (approximately 20 minutes or more), EGR will be cut off. At this time, if the vehicle is driven in 5th gear at 70 km/h for 10 minutes, EGR resumes.
   	Results of real-vehicle check: Ignition switch ON: 0% Cranking: 0% Idling with EGR off (warm up the engine): 0% Idling with EGR on (warm up the engine): 56% Running without load (2500 rpm): 56% Running without load (4500 rpm): 0.3% Driving in 3rd gear 60 km/h (37 mph): 57% Driving in 3rd gear 60 km/h (37 mph) during PM regeneration: 0.3% Driving with the accelerator fully open at 2000 rpm: 0.3% Driving with the accelerator fully open at 3000 rpm: 0.3% Driving with the accelerator fully open at 4500 rpm: 0%

HINT:

1. The purpose of the following examples is help to you understand the relationship between each Data List item when a certain malfunction occurs. Understanding this relationship helps you find the root cause easier.
   
2. The following are examples of actual malfunctions of a common rail diesel engine.
   
3. Use them for reference when diagnosing malfunctions.
   
4. These are not data of IQ 1ND-TV.
   

1. Supply pump malfunction (suction control valve momentarily sticking)
   

   
   
   
   





2. Fuel injectors sticking
   

   
   
   
   

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:

When replacing the ECM and/or fuel injector, the ECM needs Registration and Initialization (Click here).

HINT:

Before troubleshooting, conduct the following:

1. (a) Check the fuel quality.
   
2. (b) Check the fuel line for air.
   
3. (c) Check the fuel system for blockages.
   
4. (d) Check the air filter.
   
5. (e) Check the engine oil.
   
6. (f) Check the engine coolant.
   
7. (g) Check the engine idling speed and maximum engine speed.
   
8. (h) Check the vacuum pump.
   

1. Identify when shuddering occurs.
   

   Result 

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

B	REPAIR OR REPLACE CLUTCH SYSTEM

A

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

   OK:

   The wire harnesses and connectors are connected securely.
   

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

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

1. Connect the intelligent tester to the DLC3.
   

2. Start the engine and warm it up until the engine coolant temperature sensor reaches 75°C (167°F) or more.
   

   HINT:

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

3. Turn the tester on.
   

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

5. Take a snapshot of the following Data List items.
   

   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. The data in the list below is that of a normal vehicle, but as the data varies between individual vehicles, this data should only be used for reference.
      
   2. Detailed graphs can be displayed by transferring the stored snapshot data from the tester to a PC (personal computer) with Intelligent Viewer installed.
      
   3. Check the Data List at idling and at 3000 rpm with no load after the engine is warmed up.
      
   
   
   
   
   
   
   
   
   

   Data Condition Idling (Engine Warmed Up, A/C Off, Shift Lever in neutral) 

   Data List	Value	Unit
   Engine Speed	773	rpm
   MAP	99	kPa
   MAF	5.05	gm/sec
   Target Common Rail Pressure	25000	kPa
   Fuel Press	25210	kPa
   Target Pump SCV Current	1161.0	mA
   Injection Volume	4.58	mm3/st
   VN Turbo Command	90	%
   Target EGR Position	56.0	%
   Actual EGR Valve Pos.	55.6	%
   Target Throttle Position	0	%
   Actual Throttle Position	0	%
   Accel Position	0.00	%
   Atmosphere Pressure	99	kPa
   Coolant Temp	88	°C
   Calculate Load	16.0	%
   Pilot 1 Injection Period	228	μs
   Pilot 2 Injection Period	0	μs

   
   

   Data Condition at 3000 rpm (Engine Warmed Up, A/C Off, Shift Lever in neutral) 

   Data List	Value	Unit
   Engine Speed	3000	rpm
   Target Booster Pressure	131.66	kPa
   MAP	129	kPa
   MAF	31.08	gm/sec
   Target Common Rail Pressure	46210	kPa
   Fuel Press	46110	kPa
   Target Pump SCV Current	1253.0	mA
   Injection Volume	5.48	mm3/st
   VN Turbo Command	95	%
   Target EGR Position	50.5	%
   Actual EGR Valve Pos.	51.3	%
   Target Throttle Position	0	%
   Actual Throttle Position	0	%
   Accel Position	8.98	%
   Coolant Temp	70	°C
   Calculate Load	18.8	%
   Pilot 1 Injection Period	217	μs
   Pilot 2 Injection Period	0	μs

NEXT

1. Check Fuel Press and Target Common Rail Pressure in the snapshot taken when the engine was idling.
   
   

   Result 

   Result	Proceed to
   Fuel Press is within +/-10000 kPa of Target Common Rail Pressure.	A
   Fuel Press is outside range of +/-10000 kPa from Target Common Rail Pressure.	B

B	Go to step 19

A

1. Check Target Pump SCV Current in the snapshot taken when the engine was idling and at 3000 rpm with no load.
   

   Result 

   Result	Proceed to
   Target Pump SCV Current is less than 1530 mA	A
   Target Pump SCV Current is 1530 mA or more	B

B	Go to step 22

A

1. Read the fuel injector compensation codes (Click here).
   

   OK:

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

NG	Go to step 45

OK

1. Check Injection Feedback Val # and Injection Volume in the snapshot taken after the engine is warmed up and has idled for 1 minute.
   

   HINT:

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

   
   

   Result 

   Result	Proceed to
   Injection Feedback Val #1 to #4 is within the range of +/-2 mm3/st and Injection Volume is 8 mm3/st or less	A
   Injection Feedback Val #1 to #4 is within the range of +/-2 mm3/st and Injection Volume is more than 8 mm3/st	B*
   Injection Feedback Val #1 to #4 is outside the range of +/-2 mm3/st HINT: There may be a malfunction in the corresponding cylinder.	C

   HINT:

   1. *: When case "B" occurs, usually symptoms may be noticeable, such as difficult starting, rough idling, knocking or black smoke at high common rail pressure.
      
   2. If the value of Injection Volume is more than 8 mm³/st and the value of all of the Injector Feedback Val. #1 to #4 is within the threshold, replace the fuel injectors for all cylinders.
      In this case, there is a possibility that too much recirculated exhaust gas enters into the engine. Therefore, you should compare the Target EGR Position with the Actual EGR Valve Pos. by entering the following menus using the intelligent tester: Powertrain / Engine and ECT / Data List / Target EGR Position and Actual EGR Valve Pos.
      If the difference between Target EGR Position and Actual EGR Valve Pos. exceeds +/-10%, the EGR system may have a malfunction.
      

B	Go to step 38
C	Go to step 31

A

1. Check the temperature when rough idling trouble occurs.
   

   Result 

   Result	Proceed to
   Rough idling only for cold engine.	A
   Rough idling both for cold and warmed up engine.	B

B	Go to step 12

A

1. Inspect the engine coolant temperature sensor (Click here).
   

   HINT:

   Confirm that the engine coolant temperature is 60°C or more using the intelligent tester, and then leave the vehicle overnight (7 hours or more). The actual engine coolant temperature and atmosphere temperature should be very similar.

NG	REPLACE ENGINE COOLANT TEMPERATURE SENSOR (Click here)

OK

1. Check the pre-heating control circuit (Click here).
   

NG	REPAIR OR REPLACE MALFUNCTIONING PARTS

OK

1. Remove the electric EGR valve assembly.
   

2. Connect the electric EGR valve assembly connector.
   

3. Connect the intelligent tester to the DLC3.
   

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

5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position / Data List / Actual EGR Valve Pos.
   

6. When changing the Active Test value from 0 to 100%, check that Actual EGR Valve Pos. smoothly changes to the set opening angle.
   

   OK:

   Value smoothly changes to the set opening angle.
   

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

   NOTICE:

   1. When cleaning the electric EGR control valve, make sure the valve is completely closed.
      
   2. Do not forcibly open the valve, as it may be damaged or deformed.
      
   3. When cleaning the EGR valve and the diesel throttle body, use a piece of cloth with cleaning solvent. Spraying the solvent directly onto these parts or soaking the parts in the solvent may damage the parts.
      

8. 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 clearance between the valve and body.
   

   
   
   
   

   OK:

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

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

   HINT:

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

9. Remove the diesel throttle body assembly, intake air connector and EGR pipe connector.
   

10. Remove the deposits from those parts and clean them.
    

    NOTICE:

    1. When cleaning the EGR valve and the diesel throttle body, use a piece of cloth with cleaning solvent. Spraying the solvent directly onto these parts or soaking the parts in the solvent may damage the parts.
       
    2. Extreme care must be taken to prevent the removed deposits from falling into the engine unit during cleaning.
       

    HINT:

    1. Remove the intake manifold from the cylinder head when it has to be cleaned.
       
    2. Do not leave any deposits in the EGR valve assembly when cleaning the valve.
       

11. Reinstall the electric EGR valve assembly, diesel throttle body assembly, intake air connector and EGR pipe connector.
    

NG	REPLACE ELECTRIC EGR VALVE ASSEMBLY (Click here)

OK

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 / Diesel Throttle Target Angle.
   

4. When continuously changing the Active Test value to 0, 30, 60, 90, 60, 30 and 0%, check that Actual Throttle Position smoothly changes to the set opening angle.
   

   OK:

   Value smoothly changes to the set opening angle.
   

NG	REPLACE DIESEL THROTTLE BODY (Click here)

OK

1. Check whether the malfunction has been successfully repaired.
   

   OK:

   Malfunction has been repaired successfully.
   

NG	Go to step 15

OK
CHECK FOR INTERMITTENT PROBLEMS (Click here)

1. Check the fuel quality.
   

2. Check the fuel line 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.
   

8. Check the vacuum pump.
   

   OK:

   Each inspection result is normal.
   

NG	REPAIR OR REPLACE MALFUNCTIONING PARTS

OK

1. Visually check that the engine mounting insulator is installed correctly and is not crooked or twisted.
   

   OK:

   No abnormalities.
   

NG	REPAIR OR REPLACE ENGINE MOUNTING INSULATOR

OK

1. Check if 3 mm (0.12 in.) or more of carbon has accumulated on the intake manifold, cylinder head, etc. and if so, clean it off.
   

NEXT

NEXT
END

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

   1. Check for fuel filter clogging.
      

   2. Check for fuel freezing in the fuel line.
      

   3. Check for clogging or leaks in the fuel pipe and hose between the fuel tank and fuel supply pump.
      

NEXT

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

NEXT

1. Connect the intelligent tester to the DLC3.
   

2. Start the engine.
   

3. Turn the tester on.
   

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

5. Check that the fuel pressure of the common rail is within the specification below.
   

   Standard:

   Fuel Press is within +/-10000 kPa of Target Common Rail Pressure when engine is idling and running at 3000 rpm without load.
   

NG	Go to step 24

OK
END

1. 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
   B42-2 - B9-12 (PCV)	Always	Below 1 Ω

   Standard Resistance (Check for Short):

   Tester Connection	Condition	Specified Condition
   B42-2 or B9-12 (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

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.
   

   HINT:

   1. When there is a lack of fuel, fuel pressure drops.
      
   2. Inspect for fuel filter clogging.
      (Check that the fuel filter is not clogged)
      

NG	Go to step 42

OK

1. Replace the fuel supply pump (Click here).
   

NEXT

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

NEXT

1. Connect the intelligent tester to the DLC3.
   

2. Start the engine.
   

3. Turn the tester on.
   

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

5. Check that the fuel pressure of the common rail is within the specification below.
   

   Standard:

   Fuel Press is within +/-10000 kPa of Target Common Rail Pressure when engine is idling and running at 3000 rpm without load.
   

NG	Go to step 28

OK

NEXT
END

1. Replace the common rail assembly (Click here).
   

NEXT

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

NEXT

1. Connect the intelligent tester to the DLC3.
   

2. Start the engine.
   

3. Turn the tester on.
   

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

5. Check that the fuel pressure of the common rail is within the specification below.
   

   Standard:

   Fuel Press is within +/-10000 kPa of Target Common Rail Pressure when engine is idling and running at 3000 rpm without load.
   

NEXT
END

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. DTCs may be output after this Active Test. Make sure to check for DTCs after this Active Test. If any DTCs are output, make sure to clear them (Click here).
      
   2. If the engine idle speed does not change when a fuel injector is disabled, the cylinder being tested is malfunctioning.
      
   3. 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

HINT:

The speed of each cylinder can be measured (compression test) by using the intelligent tester.

In the compression test, disconnect the injector connectors of all cylinders and crank the engine for approximately 10 seconds. At this time, the speed of each cylinder is measured. If the speed of one cylinder is higher than the other cylinders, the compression pressure of that cylinder is determined to be lower than the other cylinders.

1. Warm up the engine.
   
2. Turn the ignition switch off and disconnect the injector connector of all cylinders.
   
3. Connect the intelligent tester to the DLC3.
   
4. Turn the ignition switch to ON and turn the tester on.
   
5. Enter the following menus: Powertrain / Engine and ECT / Data List / Engine Speed of Cyl #1, Engine Speed of Cyl #2, Engine Speed of Cyl #3, Engine Speed of Cyl #4 and Av Engine Speed of All Cyl.
   
6. Crank the engine for about 10 seconds.
   

   NOTICE:

   1. Do not crank the engine for more than 20 seconds.
      
   2. Use a fully-charged battery.
      

7. Read the engine speed (Engine Speed of Cyl #1 to #4, Av Engine Speed of All Cyl) displayed on the tester when the ignition switch is ON.
   

   HINT:

   Do not turn the ignition switch off when finished cranking.

   
   

   Result 

   Result	Proceed to
   Except below	A
   The values of Engine Speed Cyl #1 to #4 are within +/-10 rpm of each other.	B

   HINT:

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

8. Reconnect the injector connector of all cylinders.
   
9. Clear the DTCs.
   

B	Go to step 34

A

1. Check cylinder compression pressure (Click here).
   

NG	CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

OK

1. Replace the injector assembly (Click here).
   

NEXT

1. Register the injector compensation code (Click here).
   

2. Perform Pilot Quantity Learning Values Reset (Click here).
   

NEXT

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

NEXT

NEXT
END

1. Replace the injector assemblies (Click here).
   

NEXT

1. Register the injector compensation code (Click here).
   

2. Perform Pilot Quantity Learning Values Reset (Click here).
   

NEXT

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

NEXT

NEXT
END

1. Check and replace the clogged fuel pipe.
   

NEXT

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

NEXT

NEXT
END

1. Register the injector compensation code (Click here).
   

2. Perform Pilot Quantity Learning Values Reset (Click here).
   

NEXT

NEXT
END