G643(E) Service Manual Chapter 5. Engine Management System (EMS) 170
MI-07 System Components
The MI-07 control system provides electronic control
to the following subsystems on mobile industrial
engines:
• Spark-ignition control system
• Air throttle
• Sensors/Switches/Speed inputs
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
• Throttle body
• Air intake and air filter
• LPG mixer
• LPG pressure regulator
• Small engine control module (SECM), firmware
and calibration †
• Fuel system sensors and actuators
• Ignition system including spark plugs, cables, coils
and drivers
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.
• Open-loop fuel control with fuel specific controls
for LPG
• Speed-load spark control with tables for dwell,
timing, and fuel type
• Speed-load throttle control with table for maximum
TPS limiting
• Min/max governing
• All-speed isochronous governing
• Fixed-speed isochronous governing with three
switch-selectable speeds
• Spark timing modifiers for temperature and fuel
type
• 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.
Other system features include:
Tamper-Resistance
Special tools, equipment, knowledge, and
authorization are required to effect any changes to
the MI-07 system, thereby preventing unauthorized
personnel from making adjustments that will affect
performance or emissions.
Diagnostics
MI-07 is capable of monitoring and diagnosing
problems and faults within the system. These
include all sensor input hardware, control output
hardware, and control functions such as closed-loop
fuel control limits and adaptive learn limits. Upon
detecting a fault condition, the system notifies the
operator by illuminating the MIL and activating the
appropriate fault action. The action required by each
fault shall be programmable by the OEM customer
at the time the engine is calibrated.
Diagnostic information can be communicated
through both the service tool interface and the MIL
lamp. With the MIL lamp, it is possible to generate a
string of flashing codes that correspond to the fault
type. These diagnostics are generated only when
the engine is not running and the operator initiates a
diagnostic request sequence such as repeated
actuations of the pedal within a short period of time
following reset.
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