Diesel Common Rail

Common-rail Diesel Diagnosis Training

High-tech Diagnosis Course for Common-rail Goals – Reduce unnecessary replacing of parts (NTF parts reaches 70% in some cases) – Reduce troubleshooting time

– Improve overall customer satisfaction

2

High-tech Diagnosis Course for Common-rail Objectives – Improve system knowledge – Learn DTC detection conditions – Implement structured and logic troubleshooting procedures

3

History of Common-rail System Different variations on Common-rail – 3 Generations

Diesel EFI

Common-rail

1st-generation • Common-rail • HP2 Supply Pump • Solenoid Injector

135 MPa Max. Commonrail Pressure

2nd-generation • HP3 Supply Pump • Discharge Valve • Injector Compensation Code

135 - 160 MPa

3rd-generation

• NSR + DPNR • Piezo Injector

160 - 180 MPa

4

System Overview Common-rail System Diagram (for IMV) NE Signal G Signal

Various Signals Fuel Pressure Sensor

Engine ECU

EDU

Other Injectors Pressure Limiter Common-rail

Injector Pressure Switch

Fuel Cooler Fuel SCV Fuel SystemFilter Supply Pump Warning Light

Fuel Tank

5

System Overview Main Components for Common-rail System – Shown for the 1KD-FTV engine on the IMV Engine Front

Injection Pipe

Injector

Fuel Inlet Pipe

Common-rail

Supply Pump

•SCV (Suction Control Valve) •Fuel Temp. Sensor

•Fuel Pressure Sensor •Pressure Limiter

6

System Overview Features of Common-rail System

Injection pressure, volume and timing are controlled electrically

High accuracy engine control

High pressure fuel

Higher atomization of fuel

Stores high pressure fuel

High pressure injection in all engine speed range

• High performance and fuel economy • Low noise and vibration • Clean emission 7

System Overview Sensors and Actuators

Air Flow Meter

Intake Restrictor Valve (Step Motor)

Atmospheric Temp. Sensor

Intake Air Temp. Sensor

E-VRV (for EGR Valve Control)

Turbo Pressure Sensor

VSV (for EGR Valve Close) Camshaft Position Sensor

Injector Crankshaft Position Sensor

VSV (for Turbo Pressure Sensor) Glow Plug Water Temp. Sensor

Illustration is for 1CD-FTV on CDE120 8

ECD System Components Supply Pump – Supplies the high pressure fuel to the common-rail HP2

HP3

Type

HP2 (Outer Cam)

HP3 (Inner cam)

Generation

1st

2nd/3rd

SCV

2 (Time controlled)

1 (Duty-cycle)

Plunger

4 (Radial Type)

2 (Opposite type)

Weight [g (lb.)]

6040 (13.32)

3800 (8.38) 9

ECD System Components Supply Pump (HP3) – Fuel flow

Click! Movie

10

ECD System Components Supply Pump (HP3) – Suction and pumping operation

Click! Movie

11

ECD System Components Supply Pump (HP3) – Fuel control operation (SCV opening small)

Click! Movie

12

ECD System Components Supply Pump (HP3) – Fuel control operation (SCV opening large)

Click! Movie

13

ECD System Components Supply Pump (HP3) – The SCV opening regulates the pumping volume to control fuel pressure [Fuel Pressure Control] Fuel Pressure Sensor

SCV Controls SCV opening

Common-rail pressure (Feedback)

Calculation of target injection pressure

Engine ECU

Crankshaft Position Sensor

Accelerator Pedal Position Sensor

14

ECD System Components Supply Pump – SCV signals HP3

15

ECD System Components Common-rail – Fuel pressure sensor (PCR) • Detects the fuel pressure in common-rail and provides feedback To Injector

From Supply Pump

Common-rail

[Fuel Pressure Sensor] Sensor Tip

Pressure Limiter

Common-rail Pressure

16

ECD System Components Common-rail – Fuel pressure sensor (PCR)

Output Voltage (V)

Output characteristic

4.2

1.0 0 160 Common-rail Pressure (MPa)

17

ECD System Components Injector – High pressure injection for higher atomization Solenoid Coil

From Common-rail Control Chamber

Solenoid Coil

Return to Fuel Tank

Nozzle Spring Click! Movie

Injector Hole

Injector Pressure Voltage

Nozzle Needle

Piston

Nozzle Spring

6 or 8

135 – 180 MPa 150 V

Nozzle Needle 18

ECD System Components Injector – Small injection hall (0.14 mm) [Top of Injector]

0.14 mm

Click! Movie

19

ECD System Components Injector – Difference in the injection of gasoline and common-rail [Gasoline Engine]

[Common-rail Engine] Engine ECU

Engine ECU

Constant Low Pressure [Approx. 0.3 MPa]

EDU

Variable High Pressure [30 – 160 MPa]

Injection Volume

Injection Volume

High Long Electricity Time

Electricity Time

Common-rail Pressure

20

ECD System Components Injector – Injection volume correction • Injector compensation code Injector Compensation Code QR Code

Injection Quantity

Compensation Code Type (QR Code)

Activation Pulse Correction TQ Laser Marking

: Correction Point

21

ECD System Components Voltage

EDU Battery

EDU +B

150V

0V COM1

High Voltage Generation Circuit

High Voltage

IJT#1 IJT#2 IJT#3 IJT#4

Engine ECU

Time

INJ#1 Control Circuit

INJ#2 INJ#3 INJ#4

IJF

GND

GND 22

ECD System Components EDU – Injector drive signals

IJT#1

IJF

COM1

INJ#1

23

ECD System Components Overview ECU Inputs Basic Parameters Crankshaft Position Sensor (Ne) Accelerator Pedal Position Sensor (VA)

Injector

Correction Parameters

EDU

Intake Air Temp. Sensor (THA) Water Temp. Sensor (THW) Fuel Temp. Sensor (THF) Turbo Pressure Sensor (PIM) Vehicle Speed Sensor (SPD) Fuel Pressure Sensor (PCR) Ignition Switch (STA)

Engine ECU

EGR Valve • • •

Blower Switch (BLW) A/C Amplifier (AC)

DLC3

Alternator (ALT)

24

ECD System Components Overview ECU Outputs

Injector (Timing and duration) Suction Control Valve Various Sensor • • •

EDU (Power supply)

Engine ECU

Intake Restrictor Valve Glow Plug EGR Valve DLC3

25

ECD System Components Crankshaft Position Sensor (Ne)

Crankshaft Position Sensor

26

ECD System Components Accelerator Pedal Position Sensor (VPA, VPA2) Magnets

Hall ICs 27

ECD System Components Turbo Pressure Sensor (PIM)

Turbo Pressure Sensor

Engine ECU VSV (for Turbo Pressure Sensor)

28

ECD System Components EGR System – Intake Restrictor Valve (Rotary Solenoid Type) – A quick response and high precise are realized by driving a direct valve shaft

Intake Restrictor Valve Position Sensor

Rotary Solenoid Type Torque Motor

Magnet Steel Layer Hall IC Magnet Magnet

29

ECD System Components EGR System – Intake Restrictor Valve (Rotary Solenoid Type) • Intake restrictor shutter valve position sensor Magnet Hall IC Output Voltage (V)

VC

Engine ECU

5

VLU

E2

3.51

1 0.71 0

20 0 (Full Close)

Intake Shutter Valve Position Sensor

70 (Full Open)

100

Intake Shutter Valve Opening Angle (deg)

30

Common-rail Control Systems Overall – Consists mainly two parts, fuel metering part and fuel supply part [Electrical Part]

Various Sensor

•Injection Volume Control •Injection Timing Control •Idle Speed Control •Fuel Pressure Control

Engine ECU

•Injection rate Control •Turbo Control •EGR Control •Glow Control •Diagnosis EDU

Supply Pump Common-rail

[Mechanical Part]

Injector

31

Common-rail Control Systems Fuel Injection Volume Control – Injection volume decision • Engine ECU compares the basic and maximum injection volumes, and determine the smaller calculated value to be the final injection volume

Fuel Pressure

Basic Injection Volume

EDU Comparison

Maximum Injection Volume

Compensation Value

Decision on Duration

Injector Feedback Value

Engine ECU Injector

32

Common-rail Control Systems Fuel Injection Volume Control – Basic injection volume

Accelerator Pedal Position Sensor (VPA)

Crankshaft Position Sensor (Ne)

Basic Injection Volume (Map Data in ECU)

Water Temp. Sensor (THW)

+ Basic Injection Volume Correction

Engine ECU

Clutch Switch (CLSW) Vehicle Speed Sensor (SPD)

ISC* Correction

*: Idle Speed Control 33

Common-rail Control Systems Fuel Injection Volume Control – Basic injection volume

[Basic Injection Volume Pattern] : Amount of Accelerator Pedal Effort (VPA)

Basic Injection Volume

100% (Full Load) 50%

10%

20%

30%

Idle Engine Speed

34

Common-rail Control Systems Fuel Injection Volume Control – Maximum injection volume

Crankshaft Position Sensor (Ne)

Overheating Protection Water Temp. Sensor (THW) Fuel Temp. Sensor (THF)

Basic/Maximum Injection Volume (Map Data in ECU) Maximum Injection Volume Correction

Engine ECU

Fuel Pressure Sensor (PC, VPC) Intake Air Temp. Sensor (THA) Turbo Pressure Sensor (PIM) Air Flow Meter (VG)

Intake Air Mass

35

Common-rail Control Systems Fuel Injection Volume Control – Maximum injection volume

[Maximum Injection Volume Pattern] Injection Volume

Intake Air Volume-large

Varies by Required Volume

Intake Air Volume-small Engine Speed

36

Common-rail Control Systems Fuel Injection Volume Control – Final injection volume decision • Case of VPA 30%  Selects basic injection volume [Determining Injection Volume] Injection Volume

: Basic Injection Volume : Maximum Injection Volume

Selects lowest

30% VPA

Engine Speed

37

Common-rail Control Systems Fuel Injection Volume Control – Final injection volume decision • Case of VPA 100%  Selects Max. injection volume [Determining Injection Volume] Injection Volume

: Basic Injection Volume : Maximum Injection Volume Selects lowest

100% VPA

Engine Speed

38

Common-rail Control Systems Fuel Injection Volume Control – Injection volume correction by intake air

[Intake Air Pressure Correction] Pressure Correction

[Intake Air Temp. Correction]

Overload Protection

Increase Correction Coefficient 1

Correction Coefficient Decrease 1

Decrease

3 Turbo Pressure Sensor Output (V)

40 Intake Air Temp. (deg)

39

Common-rail Control Systems Fuel Injection Volume Control – Injection volume correction by fuel temperature

[Fuel Temp. Correction]

Increase

Correction Coefficient 1 Decrease

40 Fuel Temperature (deg)

40

Common-rail Control Systems Fuel Injection Volume Control – Injection volume correction by water temperature

[Water Temp. Correction]

Increase

Correction Coefficient

1

40 Water Temperature (deg)

41

Common-rail Control Systems Fuel Injection Volume Control – Injection duration Decides opening time of injector by final injection volume

NE Signal G Signal

Engine ECU

Controls opening timing of injector

EDU

Various Signals Common-rail From Supply Pump

Fuel Pressure Sensor

Pressure Limiter

Injector

42

Common-rail Control Systems Fuel Injection Volume Control – Injection duration

Fuel Pressure

Basic Injection Volume

Comparison Volume

Maximum Injection Volume

INJ Time Calculation

Injector Compensation Value

EDU

Injector Feedback Value

Engine ECU Injector

43

Common-rail Control Systems Fuel Injection Volume Control – Injection volume control during starting Increase Correction Coefficient

Starting Injection Volume

Basic Injection Volume

1

40 Water Temperature (deg)

+

Ignition Switch (STA)

Corrections

Water Temp. Sensor Crankshaft Position Sensor

Engine ECU

44

Common-rail Control Systems Fuel Injection Timing Control – Basic injection timing (injection timing control after started) Accelerator Pedal Position Sensor (VPA)

Crankshaft Position Sensor (Ne)

Basic Injection Timing

+ Injection Timing Correction

Engine ECU

Intake Air Temp. Sensor (THA) Turbo Pressure Sensor (PIM) Water Temp. Sensor (THW) EDU Injector

45

Common-rail Control Systems Fuel Injection Timing Control – Injection timing control during starting

Crankshaft Position Sensor (Ne) Target Injection Timing Correction

Ignition Switch (STA) Water Temp. Sensor (THW)

Engine ECU

46

Common-rail Control Systems Fuel Injection Timing Control – Injection timing corrections • Target injection timing = Basic timing + corrections [Intake Air Pressure Correction] [Basic Target Injection Timing] BTDC (deg)

: Amount of Accelerator Pedal Effort (VPA)

: Engine Speed

Timing Advance (°CA)

High rpm Low rpm

Full Load Intake Air Pressure (PIM) [Water Temp. Correction] 15 Light Load

: Water Temp.

Timing Advance (°CA)

COLD HOT

Engine Speed (rpm) Engine Speed (rpm)

47

Common-rail Control Systems Idle Speed Control – Target idle speed control

Accelerator Pedal Position Sensor (VPA) Water Temp. Sensor (THW) Target Engine Speed Calculation

Vehicle Speed Sensor (SPD) Ignition Switch (STA) A/C Amp. [Idle-up Signal] (ACT)

Comparison

Injector Volume Correction

Actual Engine Speed

Electric Load

Crankshaft Position Sensor (Ne)

Engine ECU

48

Common-rail Control Systems Idle Speed Control – Feedback correction • Idle speed fluctuations are detected by comparing t values 360°CA

Crankshaft Position Sensor Signal (Ne)

49

Common-rail Control Systems Fuel Pressure Control – Target injection fuel pressure [Fuel Pressure Control] Fuel Pressure Sensor

SCV Controls SCV opening

Common-rail pressure (Feedback) Calculation of target injection pressure

Engine ECU

Crankshaft Position Sensor

Accelerator Pedal Position Sensor

50

Common-rail Control Systems Fuel Pressure Control – Target injection fuel pressure • To control target fuel pressure in common-rail by SCV

: Calculated Final Injection Volume MAX Target Injection Fuel Pressure

MIN

Engine Speed (rpm)

51

Common-rail Control Systems Injection Rate Control – Injection rate control TDC

Small Injection Amount Prior to Ignition

Combustion Process

Injection Rate

Heat Generation Rate

High Injection Rate

[Delta Injection]

Improvement [Pilot Injection]

Heat Large Pre-mixture Combustion (NOx, Noise)

Small Pre-mixture Combustion

Ignition Delay

52

Common-rail Control Systems Injection Rate Control – Pilot injection

Accelerator Pedal Position Sensor (VPA)

Crankshaft Position Sensor (Ne)

Basic Pilot Timing

Intake Air Temp. Sensor (THA) Turbo Pressure Sensor (PIM) Correction

Pilot Injection (Volume, Timing, Interval)

Engine ECU

Water Temp. Sensor (THW)

EDU Injector

53

Common-rail Control Systems Injection Rate Control – Main injection timing

Camshaft Position Sensor Signal (G) Injection Timing

Pilot Injection

Fuel Quantity

Main Injection

54

Common-rail Control Systems Other System Operation – EGR control system Intake Restrictor Valve Position Sensor

Intake Restrictor Valve

Intake Restrictor Valve Control Motor

EGR Valve Position Sensor

Engine ECU Vacuum Pump

Atmospheric Pressure Sensor

Crankshaft Position Sensor Accelerator Pedal Position Sensor Water Temp. Sensor Turbo Pressure Sensor Intake Air Temp. Sensor

Vacuum Damper EGR Valve

Engine

E-VRV (for EGR valve control)

55

Common-rail Control Systems Other System Operation – Intake restrictor valve control system

Reduction Gears

Air Out

Intake Restrictor Valve

Air IN Step Motor Throttle Valve Fully Opened Switch

56

Common-rail Control Systems Other System Operation – Intake restrictor valve control system

Intake Restrictor Valve Control Motor

Engine ECU Intake Restrictor Valve Position Sensor

Crankshaft Position Sensor (Ne) Water Temp. Sensor (THW) Intake Air Temp. Sensor (THA) Accelerator Pedal Position Sensor (VPA)

Intake Restrictor Valve

Turbo Pressure Sensor (PIM) Ignition Switch (STA)

57

Common-rail Control Systems

After Glow Time (sec.)

Other System Operation – Glow control system

Ignition ON Switch OFF 120 Glow Plug

0

20 (68)

40 (104)

Engine Speed (rpm)

ON OFF

After Glow Time

0 Starting Engine

Engine Coolant Temp. [°C (°F)]

58