Service manual

G420F(FE) Service Manual Chapter 5. Engine Management System (EMS) 162
MI-07 System Components
The MI-07 control system provides electronic control
to the following subsystems on mobile industrial
engines:
• Fuel delivery system
• Spark-ignition control system
• Air throttle
• Sensors/Switches/Speed inputs
The chart below lists the MI-07 components required
for a G420F (E) engine operating on LP fuel.
Q’ty
G420FE G420F-LP
DESCRIPTION
1 1 Engine Control Module
(SECM 48-pin)
1 1 Camshaft Position
Sensor
1 1 Crankshaft Position
Sensor
1 1 TMAP Sensor
1 None Fuel Temperature
Sensor
1 1 Transmission Oil
Temperature Switch
2 None Oxygen Sensors
1 1 Coolant Temperature
Sensor
1 1 Engine Oil Pressure
Switch
2 None Fuel Trim Valve
4 4 Ignition Coils
4 4 Power TR
1 1 Fuel Lock Off Solenoid
N-2007 N-2001 LP Regulator
CA-100
(Certified)
CA-100 LP Mixer
1 1 Electronic Throttle Body
Key Components
The MI-07 system functions primarily on engine
components that affect engine emissions and
performance. These key components include the
following:
• Engine/Combustion chamber design
• Intake/Exhaust valve configuration, timing and lift
• Intake/Exhaust manifold design
• Catalytic converter and exhaust system
• Throttle body
• Air intake and air filter
• LPG mixer
• LPG pressure regulator
• Fuel trim valves
• Fuel trim orifices
• Small engine control module (SECM), firmware
and calibration †
• Fuel system sensors and actuators
• Ignition system including spark plugs, cables, coils
and drivers
• Gasoline injectors and fuel pressure regulator
(dual-fuel systems only)
MI-07 System Features
The MI-07 system uses an advanced speed-density
control strategy for fuel, spark, and air throttle
control. Key features include the following.
• Closed-loop fuel control with fuel specific controls
for LPG, and gasoline (MPI) fuels
• Speed-load spark control with tables for dwell,
timing, and fuel type
• Speed-load throttle control with table for maximum
TPS limiting
• Closed-loop fuel control with two oxygen sensors
(one installed pre catalyst and one installed post
catalyst). The pre-catalyst oxygen sensor includes
adaptive learn to compensate for fuel or
component drift. The post-catalyst oxygen sensor
includes adaptive learn to compensate the pre-
catalyst oxygen sensor setting for pre-catalyst
oxygen sensor drift and catalyst aging. The pre-
catalyst oxygen sensor function includes
parameters for transport delay, O2 set point,
excursion rich/lean, jump back rich/lean, and
perturbation.
• LPG fuel temperature compensation
• Min/max governing
• All-speed isochronous governing
• Fixed-speed isochronous governing with three
switch-selectable speeds
• Fuel enrichment and spark timing modifiers for
temperature and fuel type
• Transient fuel enrichment based on rate of change
of TPS
• Transient wall wetting compensation for gasoline
• Input sensor selection and calibration
• Auxiliary device control for fuel pump, fuel lock-off
solenoid, tachometer, MIL, interlocks, vehicle
speed limiting, etc.
• CANBus data transfer for speed, torque, etc.