TOYOTA RAV4 1996 Service Repair Manual

Page 371 of 1354

− 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

Page 372 of 1354

S02386
1H
1DEA1
IG1 22 IG1 IG1
E4
E4
E4
E4
E4
E4 B−R
B−Y
B−R
B−Y
BR
BRE02 E01#40 #30 #20 #10ECM
Injector 8
J/B No.1
IG Switch
8 14
7
11
7 621
202
2
2
2 B−O 31
1
1
1 No.1
No.2
No.3
No.4 B−O
B−O
B−O B−O B−O12
11
25
24
13
26
EC
BatteryFusible Link Block
MAIN
W B−R2
B
B−R
B−YB−Y
B−R
J/B No.2
AM2
FI6588
FI6538
A00064
10 V/
Division10 V/
Division(Magnification)
100 m sec./Division (idling)1 m sec./Division (Idling)
Injection durationGND GND
DI−52
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
WIRING DIAGRAM
Reference INSPECTION USING OSCILLOSCOPE
INJECTOR SIGNAL WAVEFORM
With the engine idling, measure between terminals #10, #20, #30, #40 and E01 of ECM.
HINT:
The correct waveform is as shown.

Page 373 of 1354

IG0317IG0151P25066A06618
1.1 − 1.3 mm
(0.043 − 0.051 in.)
A00404
”10 (+)
#30 (+)#40 (+) ON
#20 (+)
− DIAGNOSTICSENGINE
DI−53
1996 RAV4 (RM447U)
INSPECTION PROCEDURE
1 Check spark plug and spark of misfiring cylinder.
PREPARATION:
(a) Disconnect the high−tension cord from spark plug.
(b) Remove spark plug.
CHECK:
(a) Check the carbon deposits on electrode.
(b) Check electrode gap.
OK:
(1) No large carbon deposit present.
Not wet with gasoline or oil.
(2) Electrode gap: 1.1 − 1.3 mm (0.043 − 0.051 in.)
PREPARATION:
(a) Install the spark plug to the high − tension cord.
(b) Disconnect injector connector.
(c) Ground spark plug.
CHECK:
Check if spark occurs while engine is being cranked.
NOTICE:
To prevent excess fuel being injected from the injectors
during this test, do not crank the engine for more than 5 −
10 seconds at a time.
OK:
Spark jumps across electrode gap.
NG Replace or check ignition system (See page
IG−1).
OK
2 Check voltage of ECM terminal for injector of failed cylinder.
PREPARATION:
(a) Remove side trim cover (See page SF−61).
(b) Turn ignition switch ON.
CHECK:
Measure voltage between applicable terminal of ECM connec-
tor and body ground.
OK:
Voltage: 9 − 14 V
OK Go to step 4
NG

Page 374 of 1354

DI−54
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
3 Check injector resistance of misfiring cylinder (See page SF−21).
NG Replace injector.
OK
Check for open and short in harness and con-
nector between injector and ECM (See page
IN−30).
4 Check fuel pressure (See page SF−5).
NG Check and repair fuel pomp, pressure regulator,
fuel pipe line and filter (See page SF−1).
OK
5 Check injector injection (See page SF−21).
NG Replace injector.
OK
6 Check EGR system (See page SF−45).
NG Repair EGR system.
OK
7 Check manifold absolute pressure sensor and engine coolant temp. sensor (See
page DI−21, DI−29).

Page 375 of 1354

− DIAGNOSTICSENGINE
DI−55
1996 RAV4 (RM447U)
NG Repair or replace.
OK
Check the compression pressure (See page EM−3), valve clearance (See page EM−5) and valve
timing (See page EM−19).

Page 376 of 1354

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

Page 377 of 1354

BE6053S02469A07399
LOCK
E5 ConnectorKNK
(+)
− DIAGNOSTICSENGINE
DI−57
1996 RAV4 (RM447U)
INSPECTION PROCEDURE
1 Check continuity between terminal KNK of ECM connector and body ground.
PREPARATION:
(a) Remove side trim cover (See page SF−61).
(b) Disconnect the E5 connector of ECM.
CHECK:
Measure resistance between terminal KNK of ECM connector
and body ground.
OK:
Resistance: 1M Ω or higher
OK Go to step 3.
NG
2 Check knock sensor (See page SF−57).
NG Repair knock sensor.
OK
3 Check for open and short in harness and connector between ECM and knock
sensor (See page IN−30).
NG Repair or replace harness or connector.
OK
4 Does malfunction disappear when a good knock sensor is installed?
YES Replace knock sensor.
NO

Page 378 of 1354

A00406
0.5 V/
Division
0.5 V/
Division5 m sec./Division Knock signal waveform
0 V
0 V
100 μ sec./Division DI−58
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
Check and replace ECM (See page IN−30).
Reference INSPECTION USING OSCILLOSCOPE
With the engine racing (4,000 rpm) measure between ter-
minal KNK of ECM and body ground.
HINT:
The correct waveform is as shown.
Spread the time on the horizontal axis, and confirm that
period of the wave is 132
sec.
(Normal mode vibration frequency of knock sensor: 7.6
KHz).
HINT:
If normal mode vibration frequency is not 7.6 KHz, the sensor
is malfunctioning.

Page 379 of 1354

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

Page 380 of 1354

FI7059FI7060A06620
NENEG
G20 m sec./Division (Idling)
10 m sec./Division (Idling)
5 V/Division
5 V/Division
DI−60
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
INSPECTION PROCEDURE
1 Check resistance of crankshaft position sensor (See page IG−14).
Reference:
INSPECTION USING OSCILLOSCOPE
During cranking or idling, check between terminals G  and NE
, NE  and NE  of ECM.
HINT:
The correct waveforms are as shown.
NG Replace crankshaft position sensor.
OK
2 Check for open and short in harness and connector between ECM and crank-
shaft position sensor (See page IN−30).
NG Repair or replace harness or connector.
OK

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