Land Rover Common Rail System Crs Denso Manual

							Operation Section1–56
5.5 Other Injector Component Parts
(1) Hollow Screw with Damper
• The hollow screw with damper enhances injection quantity accuracy, by reducing the back-pressure pulsations (pres-
sure fluctuations) of the leak fuel. In addition, it minimizes the back-pressure dependence (the effect of the pressure
in the leak pipe changing the injection quantity even though the injection command is the same) of the fuel in the leak
pipe.
(2) Connector with Correction Resistor
• The connector with correction resistor has a built-in correction resistor in the connector section to minimize injection
quantity variation among the cylinders.
Q000869E
Hollow Screw with Damper
O-ring O-ring
Damper
To Fuel tank
Q000870E
Correction Resistor Terminal
Solenoid Terminal 
						

							Operation Section1–57
(3) Injector with QR Codes
• QR (Quick Response) codes have been adopted to enhance correction precision. The QR code, which contains the
correction data of the injector, is written to the engine ECU. QR codes have resulted in a substantial increase in the
number of fuel injection quantity correction points, greatly improving injection quantity precision.
< NOTE >
QR codes are a new two-dimensional code that was developed by DENSO. In addition to injection quantity correction
data, the code contains the part number and the product number, which can be read at extremely high speeds.
Q000871E
Injection Quantity
Actuating Pulse Width TQ
Pressure 
Parameter · QR Code Correction Points (Example)
10EA01EB
13EA01EB
0300 0000
0000 BC 
QR Codes
ID Codes 
						

							Operation Section1–58
Handling Injectors with QR Codes (Reference) 
- Injectors with QR codes have the engine ECU recognize and correct the injectors, so when an injector or the engine
ECU is replaced, it is necessary to register the injectors ID code in the engine ECU.
Replacing the Injector
- It is necessary to register the ID code of the injector that has been replaced in the engine ECU. 
Replacing the Engine ECU
- It is necessary to register the ID codes of all the vehicle injectors in the engine ECU. 
QD1536E
Engine ECU Spare Injector
No correction resistance, so no electrical recognition capability.
* Necessary to record the injector ID codes in the Engine ECU.
No correction resistance, so no electrical recognition capability.
* Necessary to record the injector ID codes in the Engine ECU.
Q000985E
Vehicle-Side InjectorSpare Engine ECU 
						

							Operation Section1–59
6.  DESCRIPTION OF CONTROL SYSTEM COMPONENTS
6.1 Engine Control System Diagram (Reference) 
Q000874E
Rail
Rail Pressure Sensor
Pressure Discharge Valve
Pressure Limiter
Injector Engine ECU
EDU
E-VRV for EGR
EGR Shut-Off VSV
Crankshaft Position Sensor 
(Engine Speed Sensor) Cylinder Recognition Sensor 
(TDC (G) Sensor:  HP2, 3, 4) Accelerator Position Sensor
Intake Air 
Temperature 
Sensor Airflow Meter 
(with Intake Air Temperature Sensor)
Coolant Temperature Sensor
Intake Air 
Pressure Sensor
Ignition Switch Signal
Starter Signal
Warm-Up Switch Signal
Vehicle Speed SignalSupply Pump
TDC(G) Sensor
(HP0)
SCV(HP2·3·4)
Fuel Temperature 
Sensor (HP2·3·4)
PCV(HP0)
To Fuel Tank
Charge 
Circuit 
Flow Damper 
(Large Vehicles)
PCVTDC (G) Sensor
Fuel Temperature Sensor
SCV
Fuel Temperature SensorFuel Temperature Sensor
SCV
SCV
Supply Pump
HP0
HP2HP3HP4
Fuel Temperature Sensor (HP0)
Flywheel 
						

							Operation Section1–60
6.2 Engine ECU (Electronic Control Unit)
zThe engine ECU constantly ascertains the status of the engine through signals from the sensors, calculates fuel injec-
tion quantities etc. appropriate to the conditions, actuates the actuators, and controls to keep the engine in an optimal
state. The injectors are actuated by either the EDU or the charge circuit in the engine ECU. This actuation circuit de-
pends on the specifications of the model it is mounted in. The ECU also has a diagnosis function for recording system
troubles.
6.3 EDU (Electronic Driving Unit)
(1) General Description
• An EDU is provided to enable high-speed actuation of the injectors. The EDU has a high-voltage generation device
(DC/DC converter) and supplies high voltage to the injectors to actuate the injectors at high speed.
Q000875E
Sensors Engine ECU Actuators
Cylinder Recognition Sensor 
(TDC (G) Sensor)
Crankshaft Position Sensor 
(Engine Speed Sensor)
Accelerator Position Sensor
Other Sensors
Engine ECUInjector
Supply Pump
(PCV : HP0, SCV : HP2 · HP3 · HP4)
Other Actuators
Charge Circuit 
(Built into ECU)
or
EDU
Actuation Circuit
ECU
EDU Actuation Signal
Check SignalActuation Output
Q000876E 
						

							Operation Section1–61
(2) Operation
• The high-voltage generating device in the EDU converts the battery voltage into high voltage. The ECU sends signals
to terminals B through E of the EDU in accordance with the signals from the sensors. Upon receiving these signals,
the EDU outputs signals to the injectors from terminals H through K. At this time, terminal F outputs the IJf injection
verification signal to the ECU.
6.4 Various Sensors
Various Sensor Functions
Sensor Functions
Crankshaft Position Sensor
(Engine Speed Sensor)Detects the crankshaft angle and outputs the engine speed signal.
Cylinder Recognition Sensor
(TDC (G) Sensor)Identifies the cylinders.
Accelerator Position Sensor Detects the opening angle of the accelerator pedal.
Intake Air Temperature Sensor Detects  the  temperature  of the intake air after it has passed through the turbo-
charger.
Mass Airflow Meter Detects the flow rate of the intake air. It also contains an intake air temperature sen-
sor that detects the temperature of the intake air (atmospheric temperature).
Coolant Temperature Sensor Detects the engine coolant temperature.
Fuel Temperature Sensor Detects the fuel temperature.
Intake Air Pressure Sensor Detects the intake air pressure.
Atmospheric Pressure Sensor Detects the atmospheric pressure.
GND GND
High Voltage 
Generation Circuit
Control Circuit A
L
B IJt#1
IJt#1 COM +B
IJt#2
IJt#3
IJt#4 IJt#2
IJt#3
IJt#4
IJfC
D
E
F
GMH
I
J
K ECU
Q000877E 
						

							Operation Section1–62
(1) Crankshaft Position Sensor (Engine Speed Sensor) and Cylinder Recognition Sensor
{TDC (G) Sensor}
Crankshaft Position Sensor (Engine Speed Sensor)
• The crankshaft position sensor is installed near the crankshaft timing gear or the flywheel. The sensor unit is a MPU
(magnetic pickup) type. When the engine speed pulsar gear installed on the crankshaft passes the sensor section,
the magnetic field of the coil within the sensor changes, generating AC voltage. This AC voltage is detected by the
engine ECU as the detection signal. The number of pulses for the engine speed pulsar depends on the specifications
of the vehicle the sensor is mounted in.
Cylinder Recognition Sensor {TDC (G) Sensor}
• The cylinder recognition sensor is installed on the supply pump unit for the HP0 system, but for the HP2, HP3, or HP4
system, it is installed near the supply pump timing gear. Sensor unit construction consists of the MPU type, which is
the same as for the crankshaft position sensor, and the MRE (magnetic resistance element) type. For the MRE type,
when the pulsar passes the sensor, the magnetic resistance changes and the voltage passing through the sensor
changes. This change in voltage is amplified by the internal IC circuit and output to the engine ECU. The number of
pulses for the TDC pulsar depends on the specifications of the vehicle the sensor is mounted in.
Sensor Mounting Position (Reference)
NE+ NE-
VCCTDC(G)GND
TDC(G) TDC(G)-TDC(G) GNDVCC
NE
TDC (G) 
Pulse
TDC(G)
ECU
0V
360  CA360  CA
720  CA
Engine Speed Pulsar
TDC (G) Pulsar
Q000878E
Pulsar 
(Gearless Section) 
Crankshaft Position Sensor 
(Engine Speed Sensor)Cylinder Recognition Sensor
 (TDC (G) Sensor)
Pulsar
For MPU 
TypeFor MRE 
Type
MPU TypeMPU
Type
MRE TypeMRE 
Type
MPU
Type
MRE 
Type
External View of Sensor
Shielded
Wire
Crankshaft Position Sensor 
(Engine Speed Sensor)Cylinder Recognition Sensor
(TDC (G) Sensor)
TDC (G) Input Circuit
Engine Speed
Input Circuit
Circuit Diagram
Pulse Chart (Reference)
Engine Speed
Pulse 
						

							Operation Section1–63
(2) Accelerator Position Sensor
• The accelerator position sensor converts the accelerator opening into an electric signal and outputs it to the engine
ECU. There are two types of accelerator position sensor: the hall element type and the contact type. In addition, to
provide backup in the event of breakdown, there are two systems and the output voltage is offset.
Hall Element Type
- This sensor uses a hall element to generate voltage from change in the direction of the magnetic field. A magnet
is installed on the shaft that rotates linked with the accelerator pedal, and the rotation of this shaft changes the mag-
netic field of the Hall element. The voltage generated by this change in the magnetic field is amplified by an amplifier
and input to the engine ECU.
Contact Type
- The sensor uses a contact-type variable resistor. Since the lever moves linked with the accelerator pedal, the sen-
sor resistance value varies with the accelerator pedal opening. Therefore, the voltage passing the sensor changes,
and this voltage is input to the engine ECU as the accelerator opening signal.
Q000879E
4
3
2
1
0
50 100
VACCP Output Voltage (V)
Accelerator Opening (%)Hall Elements (2)
Magnets (Pair)Amplifier No. 1 
Amplifier No. 2 
+5V
+5VA-VCC
A-VCC VACCP1
VACCP2 A-GND
A-GND
ECU
Accelerator Pedal Accelerator Pedal 
VPA2
VPA1
EP2 VPA2 VCP2 EP1 VPA1 VCP1
Accelerator Position Sensor Circuit Diagram
Output Voltage
Accelerator Pedal Position Accelerator Position Sensor
Fully Open
Fully Open
Fully
Open
Q000880E
Fully 
Closed
Fully Closed
Fully Closed Accelerator Position Sensor
Output Voltage Characteristic 
						

							Operation Section1–64
(3) Intake Air Temperature Sensor
• The intake air temperature sensor detects the temperature of the intake air after it has passed the turbocharger. The
sensor portion that detects the temperature contains a thermistor. The thermistor, which has an electrical resistance
that changes with temperature, is used to detect the intake air temperature.
(4) Mass Airflow Meter (with Built-In Intake Air Temperature Sensor)
• The mass air flow meter is installed behind the air cleaner and detects the intake air flow (mass flow). This sensor is
a hot-wire type. Since the electrical resistance of the hot wire varies with the temperature, this characteristic is utilized
to measure the intake air quantity. The mass airflow meter also has a built-in intake air temperature sensor (thermistor
type) and detects the intake air temperature (atmospheric temperature).
(5) Coolant Temperature Sensor
• The coolant temperature sensor is installed on the cylinder block and detects the coolant temperature. This sensor is
a thermistor type.
Thermistor
Q000881E
Resistance
Temperature Resistance -                        Temperature
Characteristic
E2THAFVGE2G+B
Temperature  Temperature 
Characteristic
C (
 F) Intake Air 
Temperature
Sensor
Hot WireQ000882E
Resistance
Intake Air Temperature 
Sensor Resistance - 
Q000883E
Coolant Temperature
Resistance Value
+5V
VTHW
A-GNDECU
ThermistorCoolant Temperature
Sensor ResistanceWater Temperature
Characteristic  -  
						

							Operation Section1–65
(6) Fuel Temperature Sensor
• This is a thermistor type sensor that detects the fuel temperature. In the HP2, HP3, and HP4 systems, this sensor is
installed on the supply pump unit, but in the HP0 system, it is installed on a leak pipe from an injector.
(7) Intake Air Temperature Sensor and Atmospheric Pressure Sensor
• This sensor is a semiconductor type sensor. It measures pressure utilizing the piezoelectric effect that when the pres-
sure on the silicon element in the sensor changes, its electrical resistance changes. In addition, the air pressure on
this sensor is switched between the pressure within the intake manifold and the atmospheric pressure, so both the
intake air pressure and the atmospheric pressure are detected with one sensor. The switching between intake air
pressure and atmospheric pressure is handled by the VSV (vacuum switching valve). When any one of the conditions
below is established, the VSV is switched ON for 150 msec. by command of the engine ECU to detect the atmospheric
pressure. When none of the conditions below is established, the VSV is switched OFF to detect the intake air pres-
sure.
Atmospheric Pressure Measurement Conditions
- Engine speed = 0 rpm
-Starter ON
- Stable idling state
Resistance - Temperature 
Characteristic
Temperature 
Resistance Value
Thermistor
Q000848E
Q000885E
VC
PIME2
Absolute Pressure PIM Output Voltage - Pressure 
Characteristic
Output Voltage