Denso CRS User manual

Diesel Injection Pump
COMMON RAIL SYSTEM (CRS)
OPERATION
September, 2007
00400534E
SERVICE MANUAL

© 2007 DENSO CORPORATION
All Rights Reserved. This book may not be reproduced
or copied, in whole or in part, without the written
permission of the publisher.

Revision History
Revision History
Date Revision Contents
2007. 09 • SCV: Explanation of compact SCV added to "Suction Control Valve (SCV)". (Operation: Refer
to page 1-30.)
• "Repair" section added.

Table of Contents
Table of Contents
Operation Section
1. GENERAL DESCRIPTION
1.1 Changes In Environment Surrounding The Diesel Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.2 Demands On Fuel Injection System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.3 Types Of And Transitions In ECD (ELECTRONICALLY CONTROLLED DIESEL) Systems . . . . . . . . . . . . . . 1-3
1.4 Common Rail System Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
1.5 Common Rail System And Supply Pump Transitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
1.6 Injector Transitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
1.7 Common Rail System Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
2. COMMON RAIL SYSTEM OUTLINE
2.1 Layout of Main Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
3. SUPPLY PUMP DESCRIPTION
3.1 HP0 Type. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
3.2 HP2 Type. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-18
3.3 HP3 Type. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-27
3.4 HP4 Type. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-41
4. RAIL DESCCRIPTION
4.1 Rail Functions and Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-46
4.2 Component Part Construction and Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-46
5. INJECTOR DESCRIPTION
5.1 General Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-50
5.2 Injector Construction and Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-51
5.3 Injector Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-54
5.4 Injector Actuation Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-54
5.5 Other Injector Component Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-56
6. DESCRIPTION OF CONTROL SYSTEM COMPONENTS
6.1 Engine Control System Diagram (Reference) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-59
6.2 Engine ECU (Electronic Control Unit) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-60
6.3 EDU (Electronic Driving Unit) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-60
6.4 Various Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-61
7. CONTROL SYSTEM
7.1 Fuel Injection Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-66
7.2 E-EGR System (Electric-Exhaust Gas Recirculation) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-76
7.3 Electronically Controlled Throttle (Not Made By DENSO). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-78
7.4 Exhaust Gas Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-79
7.5 DPF System (Diesel Particulate Filter) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-80
7.6 DPNR SYSTEM (DIESEL PARTICULATE NOx REDUCTION). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-82

Table of Contents
8. DIAGNOSIS
8.1 Outline Of The Diagnostic Function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-83
8.2 Diagnosis Inspection Using DST-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-83
8.3 Diagnosis Inspection Using The MIL (Malfunction Indicator Light) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-84
8.4 Throttle Body Function Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-86
9. END OF VOLUME MATERIALS
9.1 Particulate Matter (PM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-87
9.2 Common Rail Type Fuel Injection System Development History And The World’s Manufacturers. . . . . . . . . 1-87
9.3 Higher Injection Pressure, Optimized Injection Rates, Higher Injection Timing Control Precision, Higher Injection
Quantity Control Precision. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-88
9.4 Image Of Combustion Chamber Interior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-90
Repair Section
1. DIESEL ENGINE MALFUNCTIONS AND DIAGNOSTIC METHODS (BASIC KNOWL-
EDGE)
1.1 Combustion State and Malfunction Cause . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-91
1.2 Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-92
2. DIAGNOSIS OVERVIEW
2.1 Diagnostic Work Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-93
2.2 Inquiries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-94
2.3 Non-Reoccurring Malfunctions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-96
3. DTC READING (FOR TOYOTA VEHICLES)
3.1 DST-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-98
3.2 DTC Check (Code Reading via the DST-2). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-98
3.3 DTC Memory Erasure (via the DST-2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-98
4. TROUBLESHOOTING BY SYSTEM
4.1 Intake System Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-99
4.2 Fuel System Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-99
4.3 Basics of Electrical/Electronic Circuit Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-102
5. TROUBLESHOOTING
5.1 Troubleshooting According to Malfunction Symptom (for TOYOTA Vehicles). . . . . . . . . . . . . . . . . . . . . . . . 2-107
5.2 Other Malfunction Symptoms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-122
6. DIAGNOSIS CODES (DTC)
6.1 DTC Chart (Example) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-124

Operation Section 1–1
1. GENERAL DESCRIPTION
1.1 Changes In Environment Surrounding The Diesel Engine
zThroughout the world, there is a desperate need to improve vehicle fuel economy for the purposes of preventing global
warming and reducing exhaust gas emissions that affect human health. Diesel engine vehicles are highly acclaimed in
Europe, due to the good fuel economy that diesel fuel offers. On the other hand, the "nitrogen oxides (NOx)" and "par-
ticulate matter (PM)" contained in the exhaust gas must be greatly reduced to meet exhaust gas regulations, and tech-
nology is being actively developed for the sake of improved fuel economy and reduced exhaust gases.
(1) Demands on Diesel Vehicles
• Reduce exhaust gases (NOx, PM, carbon monoxide (CO), hydrocarbon (HC) and smoke).
• Improve fuel economy.
• Reduce noise.
• Improve power output and driving performance.
(2) Transition of Exhaust Gas Regulations (Example of Large Vehicle Diesel Regulations)
• The EURO IV regulations take effect in Europe from 2005, and the 2004 MY regulations take effect in North America
from 2004. Furthermore, the EURO V regulations will take effect in Europe from 2008, and the 2007 MY regulations
will take effect in North America from 2007. Through these measures, PM and NOx emissions are being reduced in
stages.
Q000989E
PM
g/kWh
NOx
g/kWh
2005 20082004 2007
3.5
2.0
2.7
0.27
1998 MY 2004 MY 2007 MY
EURO EURO EURO EURO EURO EURO
1998 MY 2004 MY 2007 MY
0.013
0.13
0.11
0.03
Europe Europe
North America
North
America
2005 20082004 2007

Operation Section
1–2
1.2 Demands On Fuel Injection System
zIn order to address the various demands that are imposed on diesel vehicles, the fuel injection system (including the
injection pump and nozzles) plays a significant role because it directly affects the performance of the engine and the
vehicle. Some of the demands are: higher injection pressure, optimized injection rate, higher precision of injection timing
control, and higher precision of injection quantity control.
< NOTE >
zFor further information on higher injection pressure, optimized injection rate, higher precision of injection timing control,
and higher precision of injection quantity control, see the material at the end of this document.

Operation Section 1–3
1.3 Types Of And Transitions In ECD (ELECTRONICALLY CONTROLLED
DIESEL) Systems
zECD systems include the ECD-V series (V3, V4, and V5) which implements electronic control through distributed pumps
(VE type pumps), and common rail systems made up of a supply pump, rail, and injectors. Types are the ECD-V3 and
V5 for passenger cars and RVs, the ECD-V4 that can also support small trucks, common rail systems for trucks, and
common rail systems for passenger cars and RVs. In addition, there are 2nd-generation common rail systems that sup-
port both large vehicle and passenger car applications. The chart below shows the characteristics of these systems.
ECD-V1
ECD-V3
ECD-V4
ECD-V5
'85 '90 '95 '00
Large Vehicle Common Rail
(HP0)
(HP2)
Passenger Car Common Rail
Common Rail System
· Maximum Injection Pressure 180 MPa
· Uses pilot injection to reduce the
engine combustion noise
· Fuel raised to high pressure by the
supply pump is temporarily
accumulated in the rail, then injected
after the injector is energized.
System
Types and
Transitions
· Maximum Injection Pressure 130 MPa
· Inner Cam Pumping Mechanism
·
Maximum Injection Pressure
100 MPa
· Uses pilot injection to reduce the
engine combustion noise.
Supply Pump Injector Rail
· The world's first SPV (electromagnetic
spill valve system) is used for fuel
injection quantity control, so the
quantity injected by each cylinder can
be controlled.
· Maximum Injection Pressure 60 MPa
Q000750E
ECD-V3 ECD-V4 ECD-V5

Operation Section
1–4
1.4 Common Rail System Characteristics
zThe common rail system uses a type of accumulation chamber called a rail to store pressurized fuel, and injectors that
contain electronically controlled solenoid valves to inject the pressurized fuel into the cylinders.
zBecause the engine ECU controls the injection system (including the injection pressure, injection rate, and injection tim-
ing), the injection system is independent and thus unaffected by the engine speed or load.
zBecause the engine ECU can control injection quantity and timing to a high level of precision, even multi-injection (mul-
tiple fuel injections in one injection stroke) is possible.
zThis ensures a stable injection pressure at all times, even in the low engine speed range, and dramatically decreases
the amount of black smoke ordinarily emitted by a diesel engine during start-up and acceleration. As a result, exhaust
gas emissions are cleaner and reduced, and higher power output is achieved.
(1) Features of Injection Control
Injection Pressure Control
• Enables high-pressure injection even at low engine speeds.
• Optimizes control to minimize particulate matter and NOx emissions.
Injection Timing Control
• Enables finely tuned optimized control in accordance with driving conditions.
Injection Rate Control
• Pilot injection control injects a small amount of fuel before the main injection.
· Injection pressure is more than double the current
pressure, which makes it possible to greatly reduce
particulate matter.
Common Rail System
Injection Pressure Control Injection Timing Control Injection Rate Control
Injection Quantity Control
Electronic Control Type
Common Rail System
Conventional
Pump
Optimized and Higher Pressure
Speed
Speed
Injection Quantity
Injection Pressure
Pre-Injection
Pilot injection After-Injection
Post-Injection
Main Injection
1324
Injection Pressure
Particulate
Injection Rate
Crankshaft Angle
Cylinder Injection Quantity Correction
Injection Quantity
Advance Angle
Q000751E

Operation Section 1–5
1.5 Common Rail System And Supply Pump Transitions
zThe world's first common rail system for trucks was introduced in 1995. In 1999, the common rail system for passenger
cars (the HP2 supply pump) was introduced, and then in 2001 a common rail system using the HP3 pump (a lighter and
more compact supply pump) was introduced. In 2004, the three-cylinder HP4 based on the HP3 was introduced.
1.6 Injector Transitions
Q000752E
1996 1998 2000 2002 2004 2006
120MPa
180MPa
135MPa
HP0
HP2
HP3
Large Trucks
Medium-Size Trucks
Common Rail
System 1st Generation Common Rail System 2nd Generation Common Rail System
Passenger Vehicles
Compact Trucks
Suction Quantity
Adjustment
Suction Quantity
Adjustment
Suction Quantity
Adjustment
Pre-Stroke Quantity Adjustment
180MPa
HP4
Q000753E
· 180MPa
· 135MPa
· 120MPa
X1 G2
97 98 99 00 01 02 03
1st Generation 2nd Generation
· Multi-Injection
· Pilot Injection
· Pilot Injection
X2

Operation Section
1–6
1.7 Common Rail System Configuration
zThe common rail control system can be broadly divided into the following four areas: sensors, engine ECU, EDU, and
actuators.
Sensors
zDetect the condition of the engine and the pump.
Engine ECU
zReceives signals from the sensors, calculates the proper injection quantity and injection timing for optimal engine oper-
ation, and sends the appropriate signals to the actuators.
EDU
zEnables the injectors to be actuated at high speeds. There are also types with charge circuits within the ECU that serve
the same role as the EDU. In this case, there is no EDU.
Actuators
zOperate to provide optimal injection quantity and injection timing in accordance with the signals received from the en-
gine ECU.
Engine Speed Sensor /
TDC (G) Sensor
Accelerator Position Sensor
Other Sensors
and Switches
Engine ECU
EDU
Supply Pump
(SCV: Suction Control Valve)
Injector
Other Actuators
Diagnosis Q000754E

Operation Section 1–7
2. COMMON RAIL SYSTEM OUTLINE
2.1 Layout of Main Components
zCommon rail systems are mainly made up of the supply pump, rail, and injectors. There are the following types accord-
ing to the supply pump used.
(1) HP0 Type
• This system is the first common rail system that DENSO commercialized. It uses an HP0 type supply pump and is
mounted in large trucks and large buses.
Exterior View of Main System Components
Configuration of Main System Components (Example of HP0)
Q000755E
InjectorSupply Pump (HP0 Type)
Rail
Q000756E
Supply Pump
PCV (Pump Control Valve)
Cylinder
Recognition Sensor
(TDC (G) Sensor)
Rail Pressure Sensor
Rail
Engine ECU
Injector
Accelerator
Position Sensor
Crankshaft Position Sensor (Engine Speed Sensor)
Fuel Temperature
Sensor
Coolant Temperature
Sensor

Operation Section
1–8
(2) HP2 Type
• This system uses a type of HP2 supply pump that has been made lighter and more compact, and is the common rail
system for passenger cars and RVs instead of the ECD-V3.
Exterior View of Main System Components
Mounting Diagram of Main System Components
Q000757E
InjectorSupply Pump (HP2 Type)
Rail
Engine ECU
EDU (Electronic Driving Unit)
EGR Valve
E-VRV
Intake Air Temperature
Sensor
Intake Air Pressure Sensor
Injector
Crankshaft Position Sensor
(Engine Speed Sensor) Rail Supply Pump Cylinder Recognition Sensor
(TDC (G) Sensor)
Rail Pressure Sensor
Accelerator Position Sensor
Coolant Temperature
Sensor
Q000758E

Operation Section 1–9
Overall System Flow (Fuel)
Q000926E
Supply Pump
Plunger
Feed Pump
Delivery Valve
SCV
(Suction
Control
Valve)
Inner Cam
Regulating Valve
Check Valve
Rail
Rail Pressure Sensor
Pressure
Limiter
Injector
TWV
Engine
ECU EDU
Various Sensors
Fuel Filter
Fuel Tank
: Flow of Injection Fuel
: Flow of Leak Fuel

Operation Section
1–10
(3) HP3 Type, HP4 Type
HP3 Type
• This system uses an HP3 type supply pump that is compact, lightweight and provides higher pressure. It is mostly
mounted in passenger cars and small trucks.
HP4 Type
• This system is basically the same as the HP3 type, however it uses the HP4 type supply pump, which has an in-
creased pumping quantity to handle larger engines. This system is mostly mounted in medium-size trucks.
Exterior View of Main System Components
Mounting Diagram for Main System Components
Q000759E
HP3 HP4
InjectorSupply Pump
Rail
Q000760E
Supply Pump
SCV
(Suction Control
Valve)
Fuel Temperature
Sensor
Fuel Temperature
Sensor
Injector
Engine ECU
EDU
DLC3 Connector
R/B
EGR Valve E-VRV for EGR
EGR Shut-Off VSV
Throttle Body
Crankshaft Position Sensor
(Engine Speed Sensor)
Cylinder Recognition Sensor
(TDC (G) Sensor)
Accelerator Position Sensor
Intake Air
Pressure
Sensor
Airflow Meter
(with Intake Air
Temperature Sensor)
Coolant Temperature Sensor
HP3 HP4
(Suction Control
Valve)
SCV
Pressure Discharge Valve
Rail Pressure Sensor

Operation Section 1–11
Overall System Flow (Fuel)
Q000927E
Supply Pump
(HP3 or HP4)
Plunger
Feed Pump
Delivery
Valve
SCV
(Suction
Control Valve)
Rail
Rail Pressure Sensor
Pressure Discharge Valve
Pressure Limiter
Injector
ECU
EDU
Various
Sensors
Fuel Filter
Fuel Tank
: Flow of Injection Fuel
: Flow of Leak Fuel

Operation Section
1–12
3. SUPPLY PUMP DESCRIPTION
3.1 HP0 Type
(1) Construction and Characteristics
• The HP0 supply pump is mainly made up of a pumping system as in conventional in-line pumps (two cylinders), the
PCV (Pump Control Valve) for controlling the fuel discharge quantity, the cylinder recognition sensor {TDC (G) sen-
sor}, and the feed pump.
• It supports the number of engine cylinders by changing the number of peaks on the cam. The supply pump rotates at
half the speed of the engine. The relationship between the number of engine cylinders and the supply pump pumping
is as shown in the table below.
• By increasing the number of cam peaks to handle the number of engine cylinders, a compact, two-cylinder pump unit
is achieved. Furthermore, because this pump has the same number of pumping strokes as injections, it maintains a
smooth and stable rail pressure.
Number of Engine Cylinders Speed Ratio
(Pump: Engine)
Supply Pump
Number of Pumping Rotations for 1
Cycle of the Engine (2 Rotations)
Number of
Cylinders Cam Peaks
4 Cylinders
1 : 2 2
24
6 Cylinders 3 6
8 Cylinders 4 8
Feed Pump
Delivery Valve
Cam x 2
PCV (Pump Control Valve)
Tappet
Element
Cylinder Recognition Sensor
(TDC (G) Sensor)
Pulsar for TDC (G) Sensor
Overflow Valve
Q000768E

Operation Section 1–13
(2) Exploded View
Q000769E
PCV
(Pump Control Valve)
Delivery Valve Element
Cylinder Recognition Sensor
(TDC (G) Sensor)
Roller
Cam
Camshaft
Tappet
Feed Pump
Priming Pump

Operation Section
1–14
(3) Supply Pump Component Part Functions
Feed Pump
• The feed pump, which is integrated in the supply pump, draws fuel from the fuel tank and feeds it to the pump chamber
via the fuel filter. There are two types of feed pumps, the trochoid type and the vane type.
Trochoid Type
- The camshaft actuates the outer/inner rotors of the feed pump, causing them to start rotating. In accordance with
the space produced by the movement of the outer/inner rotors, the feed pump draws fuel into the suction port and
pumps fuel out the discharge port.
Vane Type
- The camshaft actuates the feed pump rotor and the vanes slide along the inner circumference of the eccentric ring.
Along with the rotation of the rotor, the pump draws fuel from the fuel tank, and discharges it to the SCV and the
pumping mechanism.
Component Parts Functions
Feed Pump Draws fuel from the fuel tank and feeds it to the pumping mechanism.
Overflow Valve Regulates the pressure of the fuel in the supply pump.
PCV (Pump Control Valve) Controls the quantity of fuel delivered to the rail.
Pumping
Mechanism
Cam Actuates the tappet.
Tappet Transmits reciprocating motion to the plunger.
Plunger Moves reciprocally to draw and compress fuel.
Delivery Valve Stops the reverse flow of fuel pumped to the rail.
Cylinder Recognition Sensor {TDC (G)
Sensor}
Identifies the engine cylinders.
To Pump Chamber
From Fuel Tank
Outer Rotor
Inner Rotor
Suction Port Discharge Port
Q000770E
Suction Port
Discharge Port
Rotor Eccentric Ring
Vane
Q000771E

Operation Section 1–15
PCV: Pump Control Valve
• The PCV (Pump Control Valve) regulates the fuel discharge quantity from the supply pump in order to regulate the
rail pressure. The fuel quantity discharged from the supply pump to the rail is determined by the timing with which the
current is applied to the PCV.
Actuation Circuit
- The diagram below shows the actuation circuit of the PCV. The ignition switch turns the PCV relay ON and OFF to
apply current to the PCV. The ECU handles ON/OFF control of the PCV. Based on the signals from each sensor,
it determines the target discharge quantity required to provide optimum rail pressure and controls the ON/OFF tim-
ing for the PCV to achieve this target discharge quantity.
Pumping Mechanism
• The camshaft is actuated by the engine and the cam actuates the plunger via the tappet to pump the fuel sent by the
feed pump. The PCV controls the discharge quantity. The fuel is pumped from the feed pump to the cylinder, and then
to the delivery valve.
PCV
Ignition Switch
+B
PCV Relay
PCV1
PCV2
From PCV relay
To Rail
Q000772E
Q000773E
Camshaft
Feed Pump
PCV (Pump Control Valve)
Pulsar for TDC (G) Sensor
Delivery Valve
Cam (3 Lobes: 6-Cylinders)
Plunger
To Rail