SECTION 3 - CHASSIS & TURNTABLE
3120740
– JLG Lift –
3-99
USE OF CIRCUIT TESTING TOOLS
Do not use a test light to diagnose the engine electrical sys-
tems unless specifically instructed by the diagnostic proce-
dures. A test light can put an excessive load on an ECM circuit
and result in component damage. For volt-age measurements,
use only a digital voltmeter with an input impedance of at
least 10 megohms.
ELECTROSTATIC DISCHARGE DAMAGE
Electronic components used in the ECM are often designed to
carry very low voltage. Electronic components are susceptible
to damage caused by electrostatic discharge. Less than 100
volts of static electricity can cause damage to some electronic
components. By comparison, It takes as much as 4000 volts for
a person to feel the spark of a static discharge.
There are several ways for a person to become statically
charged. The most common methods of charging are by fric-
tion and induction.
An example of charging by friction is a person sliding across a
seat.
Charge by induction occurs when a person with well-insulated
shoes stands near a highly charged object and momentarily
touches ground. Charges of the same polarity are drained off,
leaving the person highly charged with the opposite polarity.
Static charges can cause damage, therefore it is important to-
use care when handling and testing electronic components.
To prevent possible electrostatic discharge dam-age, follow
these guidelines:
• Do not touch the ECM connector pins or soldered compo-
nents on the ECM board.
• Do not open the replacement part package until the part is
ready to be installed.
• Before removing the part from the package, ground the
package to a known good ground on the equipment.
• If the part has been handled while sliding across a seat,
while sitting down from a standing position, or while walk-
ing a distance, touch a known good ground before install-
ing the part.
Engine Performance Module (EPM)
SYSTEM DESCRIPTION
The new Engine Performance Module (EPM) engine control
system is designed to be a complete engine control system for
Ford industrial engines running on gasoline, propane or natu-
ral gas. Each module can be set up to run an engine on any
two of the three fuels in certified closed-loop control, with vir-
tually transparent on-the-fly fuel switching.
Each module can also be set up to run on a variety of elec-
tronic governing:
• It can be programmed to provide up to four specific speeds
with use of a matching toggle switch.
• It can be programmed to provide an infinite variety of speeds
(with customer-specified minimum and maximum) based on a
variable signal input.
• It can be an electronic replacement for a throttle cable with
maximum speed governing (throttle-by-wire).
• Or it can switch between throttle-by-wire and a second fixed
or variable input based on a neutral/parking brake signal.
With the new EPM system, a laptop and a communications
cable, diagnosis becomes simpler. The technician can either
view engine data with a real time graphing program, or store
that data into a numeric data file. Every time a fault is set, the
laptop will give you detailed information about the fault,
including:
• when it happened
• if the fault still exists
• a list of essential engine data from the time of the fault.
It can also display a 10 second graph of critical engine data,
from 8 seconds before the fault occurred to two seconds after.
And if you only want to view engine parameters and fault
codes, all you need is a PDA (Personal Digital Assistant) and
our easy to load software and a communications cable.
With many OEMs using control modules to control their
machinery, the new EPM has the ability to communicate
engine data to and receive commands from other control
modules through a Controller Area Network (CAN) link, with
messages written in the J1939 protocol. This allows large
amounts of data to move throughout the machine through
only two wires, and can be used to run some module based
gauge packages.
The EPM also carries auxiliary features that can be pro-
grammed to control OEM devices, allowing the OEM to elimi-
nate components from their machinery.
The EPM is also equipped with multiple safety and protection
devices that protect the user and engine from hazards such as:
• over speed
• over temperature
• over voltage
• low oil pressure
• unauthorized tampering.
Go to
Discount-Equipment.com
to
order your
parts
