2009 JAGUAR XF turn signal

3-16
04/14/2009 NP10-V8JLR: AJ133 5.0-Liter DFI V8 Engine
Technical Training
Manifold Absolute Pressure Sensor

Engine Management System

MANIFOLD ABSOLUTE PRESSURE SENSOR
The manifold absolute pressure (MAP) sensor provides
a voltage proportional to the absolute pressure in the
intake manifold. This signal allows the load on the
engine to be calculated and used within the internal cal-
culations of the ECM.
The MAP sensor is mounted on the top of the engine, at
the front behind the throttle body. The purpose of the
sensor is to measure the absolute pressure in the intake
manifold and provide information to the ECM, which
will determine the injection time.
The sensor is a semi-conductor type, which responds to
pressure acting on a membrane within the sensor, alter-
ing the output voltage.
The sensor receives a 5V reference voltage and a ground
from the ECM and returns a signal of between 0.5 – 4.5V
to the ECM. A low pressure returns a low voltage signal to
the ECM and a high pressure returns a high voltage.
The MAP sensor detects quick pressure changes in the
intake manifold after the electronic throttle. The signal is
used in conjunction with the MAF sensor signal to calcu-
late the injection period. The ECM monitors the engine
MAP sensor for faults and can store fault related codes.
Failure Modes
• Sensor open circuit
• Short circuit to battery voltage or ground
• Intake air restricted
• Default value of 1 bar (14.5 psi)
Failure Symptoms
• Rough running
• Difficult starting
• Poor driveability
NP10V8101

Specification
Function
Power Source 5V ±0.25V
Pin 1 Power
Pin 2 Ground
Pin 3 Output Signal
Operating Range 13.3 kPa – 250 kPa

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)

3-2604/14/2009NP10-V8JLR: AJ133 5.0-Liter DFI V8 EngineTechnical Training
Ambient Air Temperature SensorEngine Management System
AMBIENT AIR TEMPERATURE SENSOR
The ambient air temperature (AAT) sensor is located in
the underside of the LH exterior door mirror. The sensor
is an NTC thermistor – the element resistance decreases
as the sensor temperature increases, which produces a
low signal voltage.
The ECM supplies the sensor with a 5V reference volt-
age and ground, and measures the returned signal volt-
age as an outside temperature.
The AAT signal is used by the ECM for a number of
functions including engine cooling fan control and A/C
compressor displacement control.
The ECM also transmits an ambient temperature mes-
sage on the high speed CAN bus for use by other control
modules.
NOTE: If there is a fault with the AAT sensor, the ECM
calculates the AAT from the temperature inputs of the
IAT sensors. If the AAT sensor and the temperature
inputs of the IAT sensors are all faulty, the ECM adopts a
default ambient temperature value of 20°C (68°F).
Failure Mode
• Default value of 20°C (68°F)
PinFunction
Pin 1 5V supply
Pin 2 Ground

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