Range Rover P38
LAND ROVER V8
7
DESCRIPTION AND OPERATION
ENGINE MANAGEMENT SYSTEM - from 99MY
Description
The V8 engine for models from 99MY is controlled by
a Bosch Motronic 5.2.1 engine management system.
The ECM uses sensors to determine ambient
conditions and operating data and uses this data and
the information stored in an internal memory map to
control the electronic ignition and fuel injection. The
system features:
•
Idle speed control (ISC)
•
Adherance to regulatory emissions standards
•
Adherance to OBDII legislation for NAS vehicles
•
Security immobilisation
•
Fuelling quantity
•
Exhaust emission control using HO
2
S sensors
and closed loop fuelling
•
Knock control
•
Ignition timing
•
Interfaces with other electronic systems
including Electronic Automatic Transmission
(EAT) ECU, Transfer Box ECU, ABS ECU,
BeCM and instrument pack.
The engine management system controls the engine
fuelling by providing full sequential injection to all
cylinders. Ignition is controlled by a direct ignition
system which is provided by two quad ignition coils
operating on the wasted spark principle.
Sensors used in the engine management system
include:
•
Mass air flow sensor - to determine the mass of
air entering the engine
•
Throttle position sensor - to detect the current
throttle angle
•
Coolant temperature sensor - to detect current
engine coolant temperature
•
Exhaust gas sensors (HO
2
S) sensors - to
determine the exhaust emission levels
The ECM software program processes these signals
and determines what actions to implement based on
these signals and the internal mapped data settings.
The on-board diagnostic system detects any faults
which may occur within the EMS. The system
monitors and reports on any ignition, fuelling or
exhaust faults which cause an excessive increase in
emissions. Fault diagnosis includes failure of any
EMS sensors and actuators, as well as misfire,
catalyst damage, catalyst efficiency, fuel evaporative
loss control and exhaust leaks.
The system incorporates certain default strategies to
enable the vehicle to be driven in case of sensor
failure. This may mean that a fault is not detected by
the driver. The fault is indicated by illumination of the
malfunction indicator lamp (MIL) on North American
specification vehicles.
The ECM also communicates with the EAT ECU using
a CAN data link for the transmission of OBD
information.
A further feature of the system is ’robust
immobilisation’, (fitted to vehicles in most markets).
Upon arming the alarm, the EMS ECM disables the
injectors and the Body electrical Control Module
(BeCM) inhibits the crank relay (the vehicle cannot be
started until the alarm is disarmed).
CAUTION: System sensor connectors can
be contaminated by oil or coolant when
disconnected during repair or testing. Use
a suitable cap to prevent dirt or fluid ingress.
