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Technical TrainingNP10-V8JLR: AJ133 5.0-Liter DFI V8 Engine04/14/20093-19
Engine Management SystemThrottle Position Sensor
THROTTLE POSITION SENSOR
The engine torque is regulated via an electronic throttle
body (‘drive-by-wire’ system), where an electronic pedal
assembly determines throttle opening.
The throttle position (TP) sensor is mounted in the inte-
grated cover plate on the throttle body assembly. The
throttle body assembly is mounted at the top front of the
engine, in a similar position for both NA and SC variants.
This value is input into the ECM and the throttle is
opened to the correct angle by means of an electric direct
current (DC) motor integrated into the throttle body.
Movement of the motor is achieved by changing the
PWM signal to the DC motor, allowing it to be operated
in both directions.
The dual-output TP sensor in the throttle body is used to
determine the position of the throttle blade and the rate
of change in its angle.
A software strategy within the ECM enables the throttle
position to be calibrated each ignition cycle. When the
ignition is turned ON, the ECM commands the throttle
to open and close fully, thus performing a self-test and
calibration, learning the position of the full closed hard
stop position.Safety Precautions
CAUTION: Terminals in sensor and connec-
tor are gold-plated for corrosion/temperature
resistance – DO NOT probe.
Failure Modes
• Sensor open circuit
• Short circuit to battery voltage or ground
• If signal failure occurs the ECM will enter a limp home mode where the maximum engine speed is
2000 rpm
• Signal offset
• Vacuum leak
Failure Symptoms
• Poor engine running and throttle response
• Limp home mode – maximum 2000 rpm
• Emission control failure
• No closed loop idle speed control
NP10V8105
SpecificationFunction
Supply voltage 5V ± 0.2 V
Supply current Max. 10 mA/1 output
Tolerance – closed position ±150 mV Tolerance – WOT position ±150 mV
Operating temperature range -40°C – 160°C
(-40°F – 320°F)
Pin 1 Throttle motor valve open:
direction +
Pin 2 Throttle motor valve open:
direction –
Pin 3 Position sensor output 2
(Gold)
Pin 4 Ground (Gold)
Pin 5 Position sensor output 1
(Gold)
Pin 6 Position sensor 5V supply
(Gold)
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Technical TrainingNP10-V8JLR: AJ133 5.0-Liter DFI V8 Engine04/14/20093-25
Engine Management SystemHeated Oxygen Sensors
Safety Precautions
WARNINGS:
• Anti-seize compound used on service sensor threads may be a health hazard. Avoid skin
contact.
• Exhaust system components, catalysts in particular, operate at high temperatures and
remain hot for a long time after operation.
CAUTIONS:
• Oxygen sensors must be treated with the utmost care before and during the fitting
process. The sensors have ceramic material
within them that can easily crack if
dropped or over-torqued. They must be
tightened to the specified torque figure with
a calibrated torque wrench. Care should be
taken not to contaminate the sensor tip
when the anti-seize compound is used on
the thread.
• To prevent damage to the sensors, a special tool (box spanner) should be used when
removing.
• If the sensor sticks in the exhaust, apply de- seize product and use a repeating tighten
and loosen strategy.
• Ensure that the sensor harness is robustly secured away from moving or hot parts. Failure Modes
• Mechanical fitting and integrity of the sensor (i.e.
cracked)
• Sensor open circuit/disconnected
• Short circuit to battery voltage or ground.
• Lambda ratio outside operating band
• Crossed sensors (RH bank fitted to LH bank and vice-versa)
• Contamination from leaded fuel or other sources
• Harness damage
• Air leak into exhaust system (cracked pipe/weld or loose fixings)
Failure Symptoms
• Default to open loop fuel metering
• High CO reading
• Strong smell of sulfur (rotten eggs) until default condition
• Excess emissions
• Unstable operation
• Reduced performance
Page 30 of 36

3-2804/14/2009NP10-V8JLR: AJ133 5.0-Liter DFI V8 EngineTechnical Training
Fuel Tank Canister Purge ValveEngine Management System
FUEL TANK CANISTER PURGE VALVE
To comply with legislation in fuel evaporative loss, the evaporative emissions loss control system is used on all vehicles.
Its purpose is to minimize the evaporative loss of fuel vapor from the fuel system to the atmosphere. This is achieved by
venting the fuel system through a vapor trap – a canister filled with vapor-absorbing charcoal. The charcoal acts like a
sponge and stores the vapor until the canister is purged under the control of the ECM into the engine for combustion. The
carry-over system uses the DMTL system to check for fuel tank integrity.
The canister is connected with the intake manifold, after the throttle body, via a purge valve. This valve is opened and
closed according to a PWM signal from the ECM. The system does not work properly in the case of leakage or clog-
ging within the system or if the purge valve cannot be controlled.
The canister is purged by drawing clean air through the
charcoal, which carries the hydrocarbons into the engine
where they are combusted. To maintain driveability and
emission control, purging must be closely controlled as a
1% concentration of fuel vapor from the canister in the
air intake may shift the air/fuel ratio by as much as 20%.
Purging must be carried out at regular intervals to regen-
erate the charcoal, since the storage capacity is limited.
The purge function is alternated with the fuel metering
adaptation, as both cannot be active at the same time.
The ECM alters the PWM signal to the purge valve to con-
trol the rate of purging of the canister. The purging of the
canister is done in a controlled manner in order to maintain
the correct stoichiometric air/fuel mixture for the engine.
The ECM also ensures that the canister itself is purged
frequently enough to prevent fuel saturation of the char-
coal, which could lead to an excessive buildup of fuel
vapor (and vapor pressure) in the system, increasing the
likelihood of vapor leaks. Failure Modes
• Valve drive open circuit
• Short circuit to battery voltage or ground
• Valve/pipe work blocked
• Valve stuck open
• Pipe work leaking/disconnected
• Noisy valve
Failure Symptoms
• Engine may possibly stall on return to idle (if valve
stuck open)
• Poor idling quality (if valve stuck open)
• Fuel metering adaptations forced excessively rich if canister is clear with valve stuck open
• Fuel metering adaptations forced excessively lean if canister is saturated with valve stuck open
• Saturation of canister (if valve stuck closed)
PURGE VALVE
AIR FLOWS ENS OR
THROTTLE
FUEL TANK CARBON FILTER
INTAKE
MANIFOLD
NP10V8111
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Technical TrainingNP10-V8JLR: AJ133 5.0-Liter DFI V8 Engine04/14/20093-29
Engine Management SystemViscous Fan Control
VISCOUS FAN CONTROL (LAND ROVER ONLY)
On Land Rover vehicles, the ECM uses an electroni-
cally-controlled viscous-coupled fan to provide engine
cooling. The ECM supplies the fan with a PWM signal
that controls the amount of slippage of the fan, thus pro-
viding the correct amount of cooling fan speed and air-
flow. The EMS uses a Hall-effect sensor to determine the
fan speed.
Failure Modes
• Solenoid drive open circuit
• Short circuit to battery voltage or ground
• Fan speed monitor open circuit
• Physically damaged fan or viscous coupling