change time JAGUAR XF 2009 1.G AJ133 5.0L Engine Manual

This publication is intended for instructional purposes only. Always refer to the appropriate service publication for
specific details and procedures.
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The right is reserved to make changes at any time without notice.
© 2009 Jaguar Land Rover North America LLC

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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

3-3004/14/2009NP10-V8JLR: AJ133 5.0-Liter DFI V8 EngineTechnical Training
Controller Area Network Engine Management System
CONTROLLER AREA NETWORK
The Controller Area Network (CAN) is a high-speed
serial interface for sharing dynamic signals between elec-
tronic control modules. CAN communications are ‘self-
checked’ for errors, and if an error is detected the message
is ignored by the receiving electronic control module.
Due to the high rate of information exchange, the system
has a high degree of latency. This allows for a high num-
ber of errors to be present without reducing the data
transfer rate. In practice, this is a very reliable system.
Each CAN message is transmitted by one electronic con-
trol module and received by all other electronic control
modules on the CAN bus. Each message contains a fixed
structure of signals. The data exchanged is used so that
each electronic control module does not need to have a
hardwired sensor for each input. The CAN message iden-
tifiers are arranged by a network tool, which can guarantee
that all messages meet their specified timing needs.
Signal Overview
The CAN communication system is a differential bus
using a twisted pair that is normally very reliable. If either
or both of the wires of the twisted pair CAN bus is open-
or short-circuited, a CAN time-out fault will occur.
Below is a list of additional electronic control modules that
the ECM will communicate with on the CAN network:
• Instrument cluster
• Steering angle sensor
•TCM
• Active rear locking differential, if equipped
• Adaptive cruise control
• Electronic parking brake
Failure Modes
• CAN bus wiring short circuit or open circuit
• Incompatible software and message versions