Operation - MG MG6 Series 2011 Service Manual

Engine

Operation

ECM - General
TheECM monitors the conditions required for optimum
combustion of fuel in the cylinders using sensors located at
points around the engine. From these sensor inputs, theECM
can control and adjust the fuel quantity and timing of the fuel
being delivered to each cylinder.
The ECM contains an Electronically Erasable Programmable
Read Only Memory (EEPROM) which is programmed with
data required to run the engine.
stores a vehicle specific security code from the immobilisation
module during production. The ECM cannot function unless it
is connected to an immobilisation module with the same code.
TheECM controls the following:
• The main relay
• Fuel pump operation
• Closed loop fuelling
• Open loop fuelling
• Ignition timing
• Idle speed control
• EVAP control
• Engine immobilisation
immobilisation module)
• Engine cooling fan relays
• A/C compressor clutch control
• VCT oil control solenoids
The ECM sends and receives information to and from the
components and signals shown in the control diagram and the
following input and output table:
Inputs Processor
Battery voltage ECM
Handset position
CKP sensor
CMP sensor
TMAPsensor 1
TMAP sensor 2
Knock sensor
ECT sensor
HO2S
ETB
Version 2.0
The ECM receives and
(in conjunction with the
Outputs
Fuel injector
Coils
5V sensor supply
for TMAP sensor
ETB
ECT signal
A/C compressor
clutch relay
Purge valve
HO2S
Boost control
solenoid valve
Engine Fuel & Management System
A/C pressure
switch
PAS pressure
sensor
Alternator load
Fuel tank level
sender
Vehicle speed and
rough road signals
from ABS/DSC
ECU
Immobilisation
module
CAN Bus
Diagnostic CAN
Bus
All system inputs are in the form of analogue or digital voltage
signals, all system outputs are driver circuits which supply a
ground path to the external component. The outputs are Pulse
Width Modulated PWMsignals where the output is regulated.
TheECM interfaces with the following:
• Diagnostics via connection to the diagnostic tool
• A/C
• PAS
• Immobilisation module
• TCM
• Instrument pack
• BCM
• DSC ABS ECU
With the ignition on, the around the engine. From these
sensor inputs, the ECM can control and adjust the fuel quantity
and timing of the fuel being delivered toECM primes the
fuel system by running the fuel pump for approximately two
seconds. This is achieved by completing the ground path for
the fuel pump relay coil. TheECM references the sensors
prior to start up.
When the handset is moved to the CRANK position, the ECM
communicates with the immobilisation module. If it receives
authority to start, the ECM begins ignition and fuelling when
CKP and CMP sensor signals are detected. The ECM will
operate the fuel pump continuously when a valid CKP sensor
signal is received.
When the handset is removed, theECM switches off ignition
and fuelling to stop the engine. TheECM continues to hold the
main relay in the on position until it has completed the power
Fuel pump relay
Main relay
Cooling fan relays
MIL
CAN Bus
Diagnostic CAN
Bus
302