− DIAGNOSTICSENGINE
DI−51
1996 RAV4 (RM447U)
DTC P0300 Random / Multiple Cylinder Misfire
Detected
DTC P0301 Cylinder 1 Misfire Detected
DTC P0302 Cylinder 2 Misfire Detected
DTC P0303 Cylinder 3 Misfire Detected
DTC P0304 Cylinder 4 Misfire Detected
CIRCUIT DESCRIPTION
Misfire: The ECM uses the crankshaft position sensor and camshaft position sensor to monitor changes in
the crankshaft rotation for each cylinder.
The ECM counts the number of times the engine speed change rate indicates that misfire has occurred. And
when the misfire rate equals or exceeds the count indicating that the engine condition has deteriorated, the
MIL lights up.
If the misfire rate is high enough and the driving conditions will cause catalyst overheating, the MIL blinks
when misfiring occurs.
DTC No.DTC Detecting ConditionTrouble Area
P0300Misfiring of random cylinder is detected during any particular
200 or 1,000 revolutionsIgnition system
Injector
Fuel line pressure
EGR
Compression pressure
Valve clearance not to specification
Valve timing
Manifold absolute pressure sensor
Engine coolant temp. sensor
P0301
P0302
P0303
P0304
For any particular 200 revolutions of the engine, misfiring is
detected which can cause catalyst overheating
(This causes MIL to blink)
For any particular 1,000 revolutions of the engine, misfiring is
detected which causes a deterioration in emissions
(2 trip detection logic)
HINT:
When the 2 or more codes for a misfiring cylinder are recorded repeatedly but no Random Misfire code is
recorded, it indicates that the misfires were detected and recorded at different times.
DI3ZO−01
METER, ANALOG
Current flow activates a magnetic
coil which causes a needle to
move, thereby providing a relative
display against a background
calibration. LED (LIGHT EMITTING DIODE)
Upon current flow, these diodes
emit light without producing the
heat of a comparable light. IGNITION COIL
Convert low-voltage DC current
into high-voltage ingition current
for firing the spark plugs. 1. SINGLE
FILAMENT
GROUND
The point at which wiring attaches
to the Body, thereby providing a
return path for an electrical circuit;
without a ground, current cannot
flow.
Current flow causes a headlight
filament to heat up and emit light.
A headlight may have either a
single (1) filament or a double (2)
filament. BATTERY
Stores chemical energy and
converts it into electrical energy.
Provides DC current for the auto's
various electrical circuits.
CAPACITOR (Condenser)
A small holding unit for temporary
storage of electrical voltage.
CIRCUIT BREAKER
Basically a reusable fuse, a circuit
breaker will heat and open if too
much current flows through it. Some
units automatically reset when cool,
others must be manually reset.
DIODE
A semiconductor which allows
current flow in only one direction.
DIODE, ZENER
A diode which allows current flow
in one direction but blocks reverse
flow only up to a specific voltage.
Above that potential, it passes the
excess voltage. This acts as a
simple voltage regulator.
PHOTODIODE
The photodiode is a semiconductor
which controls the current flow
according to the amount of light.
FUSE
A thin metal strip which burns
through when too much current
flows through it, thereby stopping
current flow and protecting a
circuit from damage.
FUSIBLE LINK
A heavy-gauge wire placed in
high amperage circuits which
burns through on overloads,
thereby protecting the circuit.
The numbers indicate the cross-
section surface area of the wires.HORN
An electric device which sounds a
loud audible signal.
LIGHT
Current flow through a filament
causes the filament to heat up
and emit light.
METER, DIGITAL
Current flow activates one or
many LED's, LCD's, or fluorescent
displays, which provide a relative
or digital display.
MOTOR
A power unit which converts
electrical energy into mechanical
energy, especially rotary motion. CIGARETTE LIGHTER
An electric resistance heating
element.
DISTRIBUTOR, IIA
Channels high-voltage current
from the ignition coil to the
individual spark plugs.2. DOUBLE
FILAMENT HEADLIGHTS
FUEL
(for High Current Fuse or
Fusible Link.)
(for Medium Current Fuse)
M
16
E GLOSSARY OF TERMS AND SYMBOLS
