Pontiac Fiero 1988 Service Manual page 441

6E-14 DRIVEABILITY AND EMISSIONS - FUEL INJECTION
N.O. - NORMALLY OPEN
- State of relay contacts
or solenoid plunger
when
no voltage
is applied.
N O
x
" N I T R O G E N , O X I D E S O f - O n e of the
pollutants found in engine exhaust.
O2
- O X Y G E N
(Sensor) - Monitors the oxygen
content of the exhaust system and generates a voltage
signal to the ECM.
O/L
or
O/LOOP - OPEN LOOP
- Describes ECM fuel
control without use of oxygen sensor information.
OUTPUT
- Result of a function typically controlled
by the ECM.
OXYGEN SENSOR. EXHAUST
- Device that detects
the amount of oxygen (O2) in the exhaust stream.
P.A.I.R - PULSE AIR INJECTION REACTOR
system -
pulsed air directed into engine to reduce exhaust
emissions.
PCV - POSITIVE C R A N K C A S E V E N T I L A T I O N -
Prevent fumes in crankcase from passing into
atmosphere.
PFI - PORT FUEL INJECTION
P/N - PARK/NEUTRAL
PORT - EXHAUST OR INTAKE PORT
PROM - PROGRAMABLE READ ONLY MEMORY-
an electronic term used to describe the engine
calibration unit.
RPM - REVOLUTIONS PER MINUTE
- A measure of
rotational speed.
RVB - REAR VACUUM BRAKE - is
used to control
choke operation during cold engine conditions.
SELF-DIAGNOSTIC C O D E
- The ECM can detect
malfunctions in the system. If a malfunction occurs,
the ECM turns on the "Service Engine Soon" light. A
diagnostic code can be obtained from the ECM
through the "Service Engine Soon" light, or by use of a
"Scan" tool. This code will indicate the area of the
malfunction.
SES - SERVICE ENGINE SOON LIGHT
- Lights when
a malfunction occurs in Computer Command Control
system.
TACH - TACHOMETER
TBI - THROTTLE B O D Y INJECTION
(Unit) - is
controlled by the ECM to supply precise air/fuel
mixture into the intake manifold.
TCC - TRANSMISSION / TRANSAXLE CONVERTER
CLUTCH
- ECM controlled solenoid in transmission
which positively couples the transmission to the
engine.
THERM AC - THERMOSTATIC AIR C L E A N E R -
provides
preheated air
to intake manifold to provide
better driveability when engine is cold.
TPS - THROTTLE POSITION SENSOR
- Device that
tells the ECM
the t h r o t t l e
position.
TVS - THERMAL V A C U U M SWITCH
- Used to
control vacuum in relationship to engine temperature.
V - V O L T
V«6 - SIX CYLINDER ENGINE
- Two banks of
cylinders, arranged in a "V".
V-S
- EIGHT CYLINDER ENGINE
- Two banks of
cylinders, arranged in a "V".
V A C U U M
- Negative pressure; less than
atmospheric pressure.
V A C U U M , M A N I F O L D
- Vacuum source in
manifold below throttle plate.
V A C U U M , PORTED
- A vacuum source above
(atmospheric side) of closed throttle plate.
V A C SENSOR
- Abbreviation for differential
pressure sensor which is a vacuum sensor.
VIN - VEHICLE IDENTIFICATION NUMBER.
VSS - VEHICLE SPEED SENSOR
- Sensor which
sends vehicle speed information to the ECM.
WASTEGATE - A
means of controlling the amount
of boost available for a Turbo charged engine.
WOT - WIDE OPEN THROTTLE.
WIRING H A R N E S S SERVICE
The ECM wire harness electrically connects the
ECM to the various solenoids, switches, and sensors in
vehicle engine compartment. The ECM is located
inside the vehicle passenger compartment.
Most connectors in the engine compartment are
protected against moisture and dirt which could create
oxidation and deposits on the terminals. This
protection is important because of the very low voltage
and current levels found in the electronic system. The
connectors have a lock which secures the male and
female terminals together. A secondary lock holds the
seal and terminal into the connector.
GENERAL
Molded-on connectors (like Metri-Pack) require
complete replacement of the connector. This means
splicing a new connector assembly into the harness.