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EDF
Electro-Drive Fan relay.
The ECA energizes this
relay to apply power to the
Electro-Drive Fan (mounted
in front
of the radiator) for engine
cooling purposes. The fan
is only turned on when the
ECA determines cooling is
necessary.
EDIS
Electronic Distributorless
Ignition System. Ford
technical manuals use
EDIS when referring to a
particular distributorless
ignition system where a
separate module (EDIS
module) directly controls
spark firing and
synchronization. All the
ECA does is send a signal
requesting a particular
spark timing based on
engine operation. (Refer to
SAW definition.) The EDIS
module and associated
sensors take care of all
other aspects of ignition
system operation.
EEC-IV
Electronic Engine Control
system, version 4. The
name for Ford’s
computerized engine
control system used on
vehicles starting in 1983.
The system consists of a
control module (ECA)
containing a computer, and
several different sensors
and actuators. The system
controls fuel delivery, idle
speed, ignition timing and
various emission devices.
EFI
Electronic Fuel Injection. In
common usage, this term
applied to any system
where a computer controls
fuel delivery to an engine
by using fuel injectors. In
Ford vehicle usage, an EFI
system is one using one
injector for each cylinder.
The injectors are mounted
in the intake manifold. The
injectors are fired in groups
(“banks”). Usually all
injectors on one side of the
engine are fired together.
Injectors are fired
individually in SFI engines
(see SFI definition).
EGO
Exhaust Gas Oxygen
sensor. The EGO sensor is
threaded into the exhaust
manifold, directly into the
stream of the exhaust
gases. The ECA uses the
sensor to “fine tune” fuel
delivery. The sensor
generates a voltage of 0.6
to 1.1 volts when the
exhaust gas is rich (low
oxygen content). The
voltage changes to 0.4
volts or less when the
exhaust gas is lean (high
oxygen content). The
sensor only operates after
it reaches a temperature of
349°C (660°F).
EGR
Exhaust Gas Recirculation.
The EGR system
recirculates exhaust gases
back into the intake
manifold to reduce NOx
emissions. Various types of
systems are in use on
different vehicles. Usually
the ECA directly controls
EGR flow, but on some
vehicles it may just activate
a system controlled by non-
electronic means. Vacuum
controlled EGR valves are
normally closed. Applying
vacuum opens the valve.
EGR-C
EGR Control solenoid. Used
in certain EGR systems.
The ECA energizes this
actuator to apply vacuum
(and thus open) the EGR
valve. Used along with the
EGR-V solenoid.
EGR S/O
EGR valve Shut-Off
solenoid. Used in
mechanically operated
EGR systems where the
ECA does not control EGR
flow. The ECA can
completely stop flow by
energizing this solenoid, if
engine operating conditions
require this.
EGR-V
EGR Vent solenoid. Used
in certain EGR systems.
The ECA energizes this
actuator to vent vacuum
(and thus close) the EGR
valve. Used along with the
EGR-C solenoid.
EHC
Exhaust Heat Control
solenoid. The ECA
energizes this solenoid to
apply vacuum (and thus
activate) the EHC valve.
When activated, this valve
diverts hot gases from the
exhaust manifold to the
intake manifold heat riser
pad. Heat is transferred
from the exhaust gas to the
riser pad, which in turn
heats the incoming air. This
aids in fuel atomization for
better combustion efficiency
during engine warm-up.
EIC
Electronic Instrument
Cluster. A vehicle instrument
panel using electronic
displays (numbers or bar
graph type) in place of
standard gauges. Receives
information from the ECA by
using the Data
Communications Link (DCL).
EMI
Electromagnetic
Interference. Undesired
signals interfering with a
needed signal. For
example: static on a radio
brought about by lightning
flashes or closeness to
high voltage power lines.
EPC
Electronic Pressure Control
solenoid. Located in certain
electronically controlled
transmissions. Used by the
ECA to set hydraulic line
pressures inside the
transmission – for soft or
firm shifting (depending
upon vehicle acceleration).
EVP
EGR Valve Position sensor.
This sensor is mounted on
top of the EGR valve. It
monitors the position of the
EGR valve stem (that is,
how far the valve is open).
This signal allows the ECA
to calculate EGR flow at
any time.
EVR
EGR Vacuum Regulator
solenoid. This solenoid is
controlled by a duty cycle
signal from the ECA and is
used to vary the amount of
vacuum applied to the EGR
valve. The solenoid not
only controls the vacuum, it
also functions as a vent to
allow the EGR valve to
close. The ECA controls
the amount of EGR valve
opening by adjusting the
vacuum being applied.
(See Duty Cycle definition.)
