1996 TOYOTA RAV4 Speed sensor

− 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

P19750
Knock Sensor 1
E1 KNKECM
10
E5 B
1 DI−56
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
DTC P0325 Knock Sensor 1 Circuit Malfunction
CIRCUIT DESCRIPTION
A knock sensor is fitted to the cylinder block to detect engine knocking. This sensor contains a piezoelectric
element which generates a voltage when it becomes deformed, which occurs when the cylinder block vi-
brates due to knocking. If engine knocking occurs, ignition timing is retarded to suppress it.
DTC No.DTC Detecting ConditionTrouble Area
P0325No knock sensor 1 signal to ECM with engine speed 1,200 rpm
or more (2 trip detection logic)Open or short in knock sensor 1 circuit
Knock sensor 1 (looseness)
ECM
If the ECM detects the above diagnosis conditions, it operates the fail safe function in which the corrective
retard angle value is set to the maximum value.
WIRING DIAGRAM
DI3ZP−01

S02414
Distributor
Camshaft Position Sensor
(Built into Distributor)
D16
D16E4
E4
E4 1
B
R
W
G 1
2G4 5
17NE 
NE 
E1 ECM
Crankshaft Position Sensor2G 
W
− DIAGNOSTICSENGINE
DI−59
1996 RAV4 (RM447U)
DTC P0335 Crankshaft Position Sensor ”A” Circuit
Malfunction
CIRCUIT DESCRIPTION
Crankshaft position sensor (NE signal) consists of a signal plate and pickup coil.
The NE signal plate has 34 teeth and is mounted on the crankshaft. The NE signal sensor generates 34
signals for every engine revolution. The ECM detects the standard crankshaft angle based on the G signals,
and the actual crankshaft angle and the engine speed by the NE signals.
DTC No.DTC Detecting ConditionTrouble Area
P0335
No crankshaft position sensor signal to ECM during cranking
(2 trip detection logic)Open or short in crankshaft position sensor circuit
Crankshaft position sensor
Starter
ECM
No crankshaft position sensor signal to ECM with engine
speed 600 rpm or more
(2 trip detection logic)
WIRING DIAGRAM
DI3ZQ−01

− DIAGNOSTICSENGINE
DI−63
1996 RAV4 (RM447U)
DTC P0340 Camshaft Position Sensor Circuit
Malfunction
CIRCUIT DESCRIPTION
Camshaft position sensor (G signal) consist of a signal plate an pickup coil.
The G signal plate has one tooth on its outer circumference and is built into the distributor.
When the camshaft rotate, the protrusion on the signal plate and the air gap on the pickup coil change, caus-
ing fluctuations in the magnetic field and generating an electromotive force in the pickup coil.
The NE signal plate has 34 teeth and is mounted on the crankshaft. The NE signal sensor generates 34
signals for every engine revolution. The ECM detects the standard crankshaft angle based on the G signal
and the actual crankshaft angle and the engine speed by the NE signals.
DTC No.Detection ConditionTrouble Area
P0340No camshaft position sensor signal to ECM with engine speed
600 rpm or more
Open or short in camshaft position sensor circuit
Camshaft position sensor
Starter
ECM
WIRING DIAGRAM
Refer to page DI−59 for the WIRING DIAGRAM.
INSPECTION PROCEDURE
1 Check resistance of camshaft position sensor (signal generator) (See page
IG−14).
Reference:
INSPECTION USING OSCILLOSCOPE
Refer to page DI−59 for the OSCILLOSCOPE.
NG Replace camshaft position sensor.
OK
2 Check for open and short in harness and connector between ECM and camshaft
position sensor (See page IN−30).
NG Repair or replace harness or connector.
OK
DI3ZS−01

P25430
Throttle Body
Exhaust GasEGR Valve
Diagram ECM
VSV
Throttle
Valve
Intake Air
Chamber
EGR
Vacuum
Modulator
S02387
From
Battery6
1J2
1
1E J/B No.1EFI Main Relay
Fuse Block
11
10E423
EA12 R/B No.6ECM
J1
Junction Connector
AA
W−B B−W VSV (for EGR)
2
1
B−O
IGNEGR
E01
EAFrom
IG Switch
B−O 666 3
125
R−W
B−RB−R
W−B
− DIAGNOSTICSENGINE
DI−65
1996 RAV4 (RM447U)
DTC P0401 Exhaust Gas Recirculation Flow Insufficient
Detected
CIRCUIT DESCRIPTION
The EGR system recirculates exhaust gas, which is controlled to the proper quantity to suit the driving condi-
tions, into the intake air mixture to slow down combustion, reduce the combustion temperature and reduce
NOx emissions. The amount of EGR is regulated by the EGR vacuum modulator according to the engine
load.
If even one the following conditions is fulfilled, the VSV is turned
ON by a signal from ECM. This results in atmospheric air acting
on the EGR valve, closing the EGR valve and shutting off the
exhaust gas (EGR cut−off).
Before the engine is warmed up
During deceleration (throttle valve closed) .
Light engine load (amount of intake air very small).
Engine idling.
Engine speed over 4,400 rpm.
High engine load (amount of intake air very large)
.
DTC No.DTC Detecting ConditionTrouble Area
P0401
After the engine is warmed up, the intake manifold absolute
pressure is lager than the valve calculated by the ECM while
the EGR system is ON
(2 trip detected logic)
EGR valve stuck closed
Open or short in VSV circuit for EGR
Vacuum or EGR hose disconnected
Manifold absolute pressure sensor
EGR VSV open or close malfunction
ECM
WIRING DIAGRAM
DI3ZT−01

FI7081
Waveform of oxygen sensor
before catalystNormal
catalystWaveform of oxygen sensor
after catalyst
− DIAGNOSTICSENGINE
DI−73
1996 RAV4 (RM447U)
DTC P0420 Catalyst System Efficiency Below Threshold
CIRCUIT DESCRIPTION
The ECM compares the waveform of the oxygen sensor located before the catalyst with the waveform of
the oxygen sensor located after the catalyst to determine whether or not catalyst performance has deterio-
rated.
Air−fuel ratio feedback compensation keeps the waveform of the oxygen sensor before the catalyst repeat-
edly changing back and forth from rich to lean.
If the catalyst is functioning normally, the waveform of the oxygen sensor after the catalyst switches back
and forth between rich and lean much more slowly than the waveform of the oxygen sensor before the cata-
lyst.
But when both wavaforms change at a similar rate, it indicates that catalyst performance has deteriorated.
DTC NoDTC Detecting ConditionTrouble Area
P0420
After the engine and the catalyst are warmed up, and while the
vehicle is driven within the set vehicle and engine speed range,
the waveforms of the oxygen sensors (bank 1 sensor 1 and
bank 1 sensor 2) have the same amplitude
(2 trip detection logic)
Front TWC (front catalyst) and TWC w/pipe (rear catalyst)
Oxygen sensor
DI3ZV−01

(4) (3)
(2)
(1)
FI7132
2500 − 3000 rpm Engine Speed
Warmed up 3 minutes IG SW OFFIdling
Time
Check
FI6514
OX Signal Waveform (Oscilloscope)
200 msec./Division 1.0 V
0 V DI−74
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
CONFIRMATION ENGINE RACING PATTERN
(1) Connect the TOYOTA hand−held tester to the DLC3, or connect the probe of the oscilloscope between
terminals OX1, OX2 and E1 of ECM.
(2) Start engine and warm it up with all accessories switched OFF until water temperature is stable.
(3) Race the engine at 2500 − 3000 rpm for about 3 min.
(4) After confirming that the waveforms of the oxygen sensor, bank 1 sensor 1 (OX1), oscillate around 0.5
V during feedback to the ECM, check the waveform of the oxygen senor, bank 1 sensor 2 (OX2).
HINT:
If there is a malfunction in the system, the waveform of the oxy-
gen senor, bank1 sensor 2 (OX2), is almost the same as that
of the oxygen sensors, bank 1 senor 1 (OX1), on the left.
There are some cases where, even though a malfunction ex-
ists, the MIL may either light up or not light up.

Q00515
4−pulse 4−pluse
ECM Combination
Meter No.1 Vehicle
Speed Sensor
Transaxle DI−94
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
DTC P0500 Vehicle Speed Sensor Malfunction
CIRCUIT DESCRIPTION
The No.1 vehicle speed sensor outputs a 4−pulse signal for every revolution of the rotor shaft, which is ro-
tated by the transmission output shaft via the driven gear. After this signal is converted into a more precise
rectangular waveform by the waveform shaping circuit inside the combination meter, it is then transmitted
to the ECM. The ECM determines the vehicle speed based on the frequency of these pulse signals.
DTC No.DTC Detecting ConditionTrouble Area
P0500
No vehicle speed sensor signal to ECM under the following
conditions:
(2 trip detection logic)
For A/T:
(a) Park / neutral position switch is OFF
(b) Vehicle is being driven
For M/T:
(a) Engine speed is between 2,000 rpm and 5,000 rpm
(b) Vehicle is being driven at 88 km/h (54 mph) or more
Open or short in vehicle speed sensor circuit
Vehicle speed sensor
Combination meter
ECM
DI3ZZ−01