Diesel Common Rail

(1)

Common-rail Diesel

Diagnosis Training

(2)

High-tech Diagnosis Course for Common-rail

Goals

–

Reduce unnecessary replacing of parts

(NTF parts reaches 70% in some cases)

–

Reduce troubleshooting time

–

(3)

High-tech Diagnosis Course for Common-rail

Goals

–

Reduce unnecessary replacing of parts

(NTF parts reaches 70% in some cases)

–

Reduce troubleshooting time

–

(4)

High-tech Diagnosis Course for Common-rail

Objectives

–

Improve system knowledge

–

Learn DTC detection conditions

–

Implement structured and logic troubleshooting

procedures

(5)

History of

Common-ra

il

System

Different variations on Common-rail

–

3 Generations

Diesel

EFI

Common-rail

2nd-generation

•

HP3 Supply Pump

•

Discharge Valve

•

Injector Compensation

Code

135 - 160 MPa

3rd-generation

• •

NSR + DPNR

•

Piezo Injector

160 - 180 MPa

1st-generation

• •

Common-rail

•

HP2 Supply Pump

•

Solenoid Injector

135 MPa

Max. Max. Common-rail Pressure rail Pressure

(6)

System Overview

Common-rail System Diagram (for IMV)

Fuel Pressure Fuel Pressure Sensor Sensor Pressure Pressure Limiter Limiter Supply Pump Supply Pump SCVSCV

Engine

ECU

Fuel Tank Fuel Tank Injector Injector

NE Signal

G Signal

Various

Signals

Common-rail Common-rail Fuel Cooler Fuel Cooler Pressure Pressure Switch Switch Fuel Fuel Filter Filter Fuel System Fuel System Warning Light Warning Light Other Injectors Other Injectors

EDU

(7)

System Overview

Main Components for Common-rail System

–

Shown for the 1KD-FTV engine on the IMV

Supply Pump

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

Injector

Engine

Front

Injection Pipe

Fuel Inlet Pipe

Common-rail

•Fuel Pressure Sensor •Pressure Limiter

(8)

System Overview

Features of Common-rail System

High pressure fuel

Stores high pressure fuel

Injection pressure, volume and

timing are controlled electrically

•

High performance and fuel economy

•

Low noise and vibration

•

Clean emission

High pressure injection in all

engine speed range

Higher atomization of fuel

High accuracy engine control

(9)

System Overview

Sensors and Actuators

Air Flow Meter Atmospheric Temp. Sensor

Camshaft Position Sensor

Intake Restrictor Valve (Step Motor)

Glow Plug Turbo Pressure Sensor Water Temp. Sensor Injector Crankshaft Position Sensor Intake Air Temp. Sensor VSV (for Turbo Pressure Sensor) E-VRV (for EGR

Valve Control) VSV (for EGR

Valve Close)

(10)

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)

(11)

ECD System Components

Supply Pump (HP3)

–

Fuel flow

Click! Movie

(12)

ECD System Components

Supply Pump (HP3)

–

Suction and pumping operation

Click! Movie

(13)

ECD System Components

Supply Pump (HP3)

–

Fuel control operation (SCV opening small)

Click! Movie

(14)

ECD System Components

Supply Pump (HP3)

–

Fuel control operation (SCV opening large)

Click! Movie

(15)

ECD System Components

Supply Pump (HP3)

–

The SCV opening regulates the pumping volume to

control fuel pressure

Controls SCV opening Common-rail pressure (Feedback) Accelerator Pedal Position Sensor SCV

Engine ECU

Fuel Pressure Sensor Crankshaft Position Sensor

Calculation of

target injection

pressure

[Fuel Pressure Control]

(16)

ECD System Components

Supply Pump

–

SCV signals

(17)

ECD System Components

Common-rail

–

Fuel pressure sensor (PCR)

•

Detects the fuel pressure in common-rail and

provides feedback

Common-rail

Pressure

Sensor Tip Pressure_Limiter

From Supply Pump

Common-rail To Injector

(18)

ECD System Components

Common-rail

–

Fuel pressure sensor (PCR)

0

160 Common-rail Pressure (MPa)

1.0

4.2

O u t p u t V o l t a g e ( V )

Output characteristic

(19)

ECD System Components

Injector

–

High pressure injection for higher atomization

Nozzle

Needle

Piston

Solenoid

Coil

Return to

Fuel Tank

From

Common-rail

Nozzle

Spring

Click! Movie

Nozzle

Spring

Nozzle

Needle

Control

Chamber

Solenoid

Coil

Injector Hole

6 or 8

Injector Pressure

135

–

180 MPa

(20)

ECD System Components

Injector

–

Small injection hall (0.14 mm)

Click! Movie

0.14 mm

[Top of Injector]

(21)

ECD System Components

Injector

–

Difference in the injection of gasoline and common-rail

[Gasoline Engine]

[Common-rail Engine]

Engine

ECU

Electricity Time I n j e c t i o n V o l u m e Electricity Time Common-rail Pressure EDU

Engine

ECU

Constant Low Pressure [Approx. 0.3 MPa] Variable High Pressure [30 – 160 MPa] Long High Injection Volume

(22)

ECD System Components

Injector

–

Injection volume correction

•

Injector compensation code

QR Code

Injector

Compensation Code

Laser Marking

Compensation Code Type (QR Code)

: Correction Point

Activation Pulse Correction TQ

I n j e c t i o n Q u a n t i t y

(23)

High Voltage Generation

Circuit

ECD System Components

EDU

IJT#1 +B

EDU

Battery

IJT#2 IJT#3 IJT#4 IJF INJ#1 INJ#2 INJ#3 INJ#4 GND GND COM1 Control Circuit V o l t a g e

Time

150V

0V

Engine

ECU

High

Voltage

(24)

ECD System Components

EDU

–

Injector drive signals

IJT#1

INJ#1 COM1 IJF

(25)

ECD System Components

Overview ECU Inputs

Crankshaft Position Sensor (Ne) Accelerator Pedal Position Sensor (VA)

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) Basic Parameters

Correction Parameters

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

Alternator (ALT)

Engine

ECU

Injector

EDU

EGR Valve DLC3 • • •

(26)

ECD System Components

Overview ECU Outputs

Injector (Timing and duration) Suction Control Valve

EDU (Power supply) Intake Restrictor Valve

Glow Plug DLC3

Engine

ECU

Various Sensor • • • EGR Valve

(27)

ECD System Components

Crankshaft Position Sensor (Ne)

(28)

ECD System Components

Accelerator Pedal Position Sensor (VPA, VPA2)

Hall

ICs

(29)

ECD System Components

Turbo Pressure Sensor (PIM)

Turbo Pressure Sensor VSV (for Turbo Pressure Sensor)

Engine

ECU

(30)

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

Hall IC

Magnet

Steel Layer

Magnet

Intake Restrictor Valve

Position Sensor

Rotary Solenoid Type

Torque Motor

(31)

ECD System Components

EGR System

–

Intake Restrictor Valve (Rotary Solenoid Type)

•

Intake restrictor shutter valve position sensor

Intake Shutter Valve Opening Angle (deg)

O u t p u t V o l t a g e ( V ) 0

Engine

ECU

VC VLU Hall IC Magnet E2 0 (Full Close) 70 (Full Open)

Intake Shutter

Valve Position

Sensor

1 5 0.71 20 100 3.51

(32)

Common-rail Control Systems

Overall

–

Consists mainly two parts, fuel metering part and fuel

supply part

[Electrical Part]

[Mechanical Part]

Supply Pump Injector EDU

Various Sensor

_{Engine ECU}

•Injection Volume Control •Injection Timing Control •Idle Speed Control

•Fuel Pressure Control

•Injection rate Control •Turbo Control

•EGR Control •Glow Control •Diagnosis

(33)

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

Engine ECU

EDU Injector Basic Injection Volume Maximum Injection Volume Fuel Pressure Compensation Value Injector Feedback Value Decision on Duration Comparison

(34)

33

ISC* Correction

Common-rail Control Systems

Fuel Injection Volume Control

–

Basic injection volume

Engine ECU

Basic Injection Volume

(Map Data in ECU)

Basic Injection Volume Correction Accelerator Pedal

Position Sensor (VPA)

Crankshaft Position Sensor (Ne)

Water Temp. Sensor (THW)

Clutch Switch (CLSW) Vehicle Speed Sensor (SPD)

*: Idle Speed Control

(35)

Common-rail Control Systems

Fuel Injection Volume Control

–

Basic injection volume

Basic

Injection

Volume

Engine Speed

[Basic Injection Volume Pattern]

: Amount of Accelerator

Pedal Effort (VPA)

Idle

10%

20%

30%

50%

100%

(Full Load)

(36)

Overheating Protection

Common-rail Control Systems

Fuel Injection Volume Control

–

Maximum injection volume

Intake Air Mass

Engine ECU

Basic/Maximum Injection Volume (Map Data in ECU)

Maximum Injection Volume

Correction

Air Flow Meter (VG) Water Temp. Sensor (THW)

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

Fuel Temp. Sensor (THF) Fuel Pressure Sensor

(37)

Common-rail Control Systems

Fuel Injection Volume Control

–

Maximum injection volume

Engine Speed

[Maximum Injection Volume Pattern]

Intake Air

Volume-small

Injection

Volume

_{Varies by}

Required Volume

Intake Air

Volume-large

(38)

Common-rail Control Systems

Fuel Injection Volume Control

–

Final injection volume decision

•

Case of VPA 30%



Selects basic injection volume

Engine Speed

Injection

Volume

30% VPA

: Basic Injection Volume

: Maximum Injection Volume

Selects lowest

[Determining Injection Volume]

(39)

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Common-rail Control Systems

Fuel Injection Volume Control

–

Injection volume correction by water temperature

[Water Temp. Correction]

Correction Coefficient

Water Temperature (deg) Increase

40 1

(43)

Common-rail Control Systems

Fuel Injection Volume Control

–

Injection duration

Pressure Limiter

Engine

ECU

NE Signal

G Signal

Various

Signals

Common-rail Injector EDU

Fuel Pressure Sensor From

Supply Pump

Decides opening time of injector by final injection volume

Controls opening timing of injector

(44)

(45)

Common-rail Control Systems

Fuel Injection Volume Control

–

Injection volume control during starting

Engine ECU

Basic Injection Volume

Corrections Water Temp. Sensor

Crankshaft Position Sensor

+

Starting Injection Volume

Ignition Switch (STA) Correction

Coefficient

Water Temperature (deg) Increase

40 1

(46)

Common-rail Control Systems

Fuel Injection Timing Control

–

Basic injection timing

(injection timing control after started)

Engine ECU

Accelerator Pedal Position Sensor (VPA)

+

EDU Injector Injection Timing Correction

Basic Injection Timing

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

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