3.1.13-4
CS35 2013.04
3.1.13-4Electronic Control System - ME7
According to the performance, the
electrical control system can be
divided into the following subsystems
• Fuel injection control system
• Idle speed control system
• Fuel pump control system
• Ignition timing control system
• Radiator fan control system
• Fuel steam emission control system
• A/C control system
• DVVT control system
ME7 System Input / Output Signal
The main sensor input signals of ECM of ME7
system include:
• EFP signal
• Airflow signal
• Throttle rotor angle signal
• Coolant temperature signal
• Engine speed signal
• Phase signal
• Knock sensor signal
• Oxygen sensor signal
• Vehicle speed signal
• A/C pressure signal
After the above information goes into ECM, they
are been processed then the required actuator
control signals are generated, these signals are
amplified in the output driver circuit, and are
transmitted to each corresponding actuator, these
control signals include:
• Electronic throttle motor
• Injection timing and injection duration
• Fuel pump relay
• Carbon canister control valve opening
• Ignition coil dwell angle and spark
advance angle
• A/C compressor relay
• Cooling fan relay
• Oil control valve
Fuel Injection Control
ECM controls the injection time and the injection
timing from injector to the cylinder head intake
port based on various sensors signals, to ensure
the appropriate mixed gas is provided in different
driving conditions. There are two forms of injec-
tion timing, one is synchronous injection, which
always injects at the same crankshaft angle, the
other is non - synchronous injection, which is con-
trolled based on inlet pressure temperature sen-
sors and other sensor signals.
1. Synchronous injection
When the engine starts, the air in the intake
manifold is still, the internal pressure of the
intake manifold shows as the surrounding
atmospheric pressure. Electrical throttle
opens to a certain angle based on a fixed
parameter that determined by the starting
temperature. 4 injectors will inject synchro-
nously in each cycle. Fuel injection amount
varies according to the engine temperature.
Before the engine reaches a certain speed,
the mixture need to be enriched. Once the
engine is running, the system immediately
begins to reduce the cranking enrichment,
until the end of starting (600 ~ 700 rpm), start
enriching is completely canceled.
2. Non - synchronous injection
After engine starts and the following condi-
tions are met, all fuel injectors will not be con-
trolled by the pressure / temperature sensor.
• Fuel injection system starts to inject when
fuel is disconnected.
• When the throttle opening rate is higher
than the specified value (throttle opens
too fast).
Non - synchronous injection system is gener-
ated quickly under above two situations.
3. Injection time
The main elements of identifying the fuel
injection time is based on the basic injection
time value thatcalculated according to the
engine speed, the intake manifold pressure
temperature (air intake flow rate), and a vari-
ety of the compensation value that is deter-
mined by the sensor signals which is used for
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