S01830
Fuel Inlet Hose
P25066
− DIAGNOSTICSENGINE
DI−11
1996 RAV4 (RM447U)
7 Check fuel pressure.
PREPARATION:
(a) Be sure that enough fuel is in the tank.
(b) Turn ignition switch ON.
(c) Connect the TOYOTA hand−held tester to DLC3 on the
vehicle.
(d) Use ACTIVE TEST mode to operate the fuel pump.
(e) If you have no TOYOTA hand−held tester, connect the
positive (+) and negative (−) leads from the battery to the
fuel pump connector (See page SF−5).
CHECK:
Check for fuel pressure in the inlet hose when it is pinched off.
HINT:
At this time, you will hear a fuel flowing noise.
NG Proceed to page SF−5 and continue to trouble-
shoot.
OK
8 Check for spark.
PREPARATION:
(a) Disconnect the high−tension cord from spark plug.
(b) Remove spark plug.
(c) Install spark plug to high−tension cord.
(d) Disconnect injector connector.
(e) Ground the 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.
NG Proceed to page IG−1 and continue to trouble-
shoot.
OK
Proceed to matrix chart of problem systems
on page DI−20.
− DIAGNOSTICSENGINE
DI−13
1996 RAV4 (RM447U)
(b) TOYOTA Enhanced Signals
TOYOTA hand−held tester displayMeasurement ItemNormal Condition *
MISFIRE RPMEngine RPM for first misfire rangeMisfire 0: 0 RPM
MISFIRE LOADEngine load for first misfire rangeMisfire 0: 9 g/r
INJECTORFuel injection time for cylinder No.1Idling: 1.9 − 3.3 ms
IAC DUTY RATIOIntake Air Control Valve Duty Ratio Opening
ratio rotary solenoid type IAC valveIdling: 25 − 60 %
STARTER SIGStarter SignalCranking: ON
A/C SIGA/C Switch SignalA/C ON: ON
PNP SWPark / Neutral Position Switch SignalP or N position: ON
ELCTRCL LOAD SIGElectrical Load SignalDefogger S/W ON: ON
STOP LIGHT SWStop Light Switch SignalStop light switch ON: ON
FC IDLFuel Cut Idle: Fuel cut when throttle valve fully
closed, during decelerationFuel cut operating: ON
FC TAUFuel Cut TAU: Fuel cut during very light loadFuel cut operating: ON
CYL#1
CYL#2
CYL#3
CYL#4
Abnormal revolution variation for each cylinder0 %
IGNITIONTotal number of ignitions for every 1,000
revolutions0 − 2,000
EGR SYSTEMEGR system operating conditionIdling: OFF
FUEL PUMPFuel Pump SignalIdling: ON
EVAP (PURGE) VSVEVAP VSV SignalVSV operating: ON
VAPOR PRESS VSVVapor Pressure VSV SignalVSV operating: ON
A/C CUT SIGA/C Cut SignalA/C S/W OFF: ON
TOTAL FT B1Total Fuel Trim Bank 1: Average value for fuel
trim system of bank 1Idling: 0.8 − 1.2
O2 LR B1, S1
Oxygen Sensor Lean Rich Bank 1, Sensor 1
Response time for oxygen sensor output to
switch from lean to rich.
Idling after warned up: 0 − 1,000 msec.
O2 RL B1, S1
Oxygen Sensor Rich Lean Bank 1, Sensor 1
Response time for oxygen sensor output to
switch from rich to lean.
Idling after warned up: 0 − 1,000 msec.
*: If conditions are specifically stated for ”Idling” , it means the shift lever is at N or P Position, the A/C switch
is OFF and all accessory switches are OFF.
DI3Z8−02
DI−14
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
DIAGNOSTIC TROUBLE CODE CHART
HINT:
Parameters listed in the chart may not be exactly the same as your reading due to the type of instrument
or other factors.
If a malfunction code is displayed during the DTC check in check mode, check the circuit for that code listed
in the table below, for details of each code, turn to the page referred to under the ”See page” for the respec-
tive ”DTC No.” in the DTC chart.
SAE DEFINED
DTC No.
(See Page)Detection ItemTrouble AreaMILMemory
P0105
(DI−21)
Manifold Absolute
Pressure / Barometric
Pressure Circuit
MalfunctionOpen or short in Manifold absolute pressure sensor circuit
Manifold absolute pressure sensor
ECM
*1
P0106
(DI−24)
Manifold Absolute
Pressure / Barometric
Pressure Circuit
Ranger / Performance
Problem
Manifold absolute pressure sensor *1
P0110
(DI−25)Intake Air Temp. Circuit
MalfunctionOpen or short in take air temp. sensor circuit
Intake air temp. sensor
ECM
*1
P0115
(DI−29)Engine Coolant Temp. Circuit
MalfunctionOpen or short in engine coolant temp. sensor circuit
Engine coolant temp. sensor
ECM
*1
P0116
(DI−33)Engine Coolant Temp. Circuit
Range / Performance ProblemEngine coolant temp. sensor
Cooling system *1
P0120
(DI−34)Throttle / Pedal Position
Sensor / Switch ”A” Circuit
MalfunctionOpen or short in throttle position sensor circuit
Throttle position sensor
ECM
*1
P0121
(DI−38)Throttle / Pedal Position
Sensor / Switch ”A” Circuit
Range / Performance Problem
Throttle position sensor *1
P0125
(DI−39)Insufficient Coolant Temp. for
Closed Loop Fuel ControlOpen or short in oxygen sensor circuit
Oxygen sensor *1
P0130
(DI−42)Oxygen Sensor Circuit Malfunc-
tion
(Bank 1 Sensor 1)Oxygen sensor
Fuel trim malfunction *1
P0133
(DI−45)Oxygen Sensor Circuit Slow
Response
(Bank 1 Sensor 1)
Oxygen sensor *1
P0136
(DI−46)Oxygen Sensor Circuit
Malfunction
(Bank 1 Sensor 2)
Oxygen sensor *1
P0171
(DI−48)System too Lean
(Fuel Trim)
Air Intake (hose loose)
Fuel line pressure
Injector blockage
Oxygen sensor malfunction
Manifold absolute pressure sensor
Engine coolant temp. sensor
*1
*1: MIL lights up
− DIAGNOSTICSENGINE
DI−15
1996 RAV4 (RM447U) DTC No.
(See Page)
Detection ItemTrouble AreaMILMemory
P0172
(DI−48)System too Rich
(Fuel Trim)
Fuel line pressure
Injector blockage, leak
Oxygen sensor malfunction
Manifold absolute pressure sensor
Engine coolant temp. sensor
*1
P0300
(DI−51)Random / Multiple
Cylinder Misfire DetectedIgnition system
Injector
Fuel line pressure
EGR
Compression pressure
Valve clearance not to specification
Valve timing
Manifold absolute pressure sensor
Engine coolant temp. sensor
*2P0301
P0302
P0303
P0304
(DI−51)Misfire Detected
− Cylinder 1
− Cylinder 2
− Cylinder 3
− Cylinder 4
P0325
(DI−56)Knock Sensor 1 Circuit
MalfunctionOpen or short in knock sensor 1 circuit
Knock sensor 1 (looseness)
ECM
*1
P0335
(DI−59)Crankshaft Position Sensor
”A” Circuit Malfunction
Open or short in crankshaft position sensor circuit
Crankshaft position sensor
Starter
ECM
*1
P0336
(DI−62)Camshaft Position Sensor
Circuit Range / PerformanceDistributor
ECM malfunction (for back up) *1
P0340
(DI−63)Camshaft Position Sensor
Circuit Malfunction
Open or short in camshaft position sensor circuit
Camshaft position sensor
Starter
ECM
*1
P0401
(DI−65)Exhaust Gas Recirculation
Flow Insufficient Detected
EGR valve stuck close
Open or short in VSV circuit for EGR
Vacuum or EGR hose disconnected
Manifold absolute pressure sensor
EGR VSV open or close malfunction
ECM
*1
P0402
(DI−71)Exhaust Gas Recirculation
Flow Excessive Detected
EGR valve stuck open
Vacuum or EGR hose is connected to wrong post
Manifold absolute pressure sensor
ECM
*1
P0420
(DI−73)Catalyst System Efficiency
Below ThresholdThree−way catalytic converter
Open or short in oxygen sensor circuit
Oxygen sensor
*1
P0440
(DI−76)Evaporative Emission Control
System Malfunction
Vapor pressure sensor
Fuel tank cap incorrectly installed
Fuel tank cap cracked or damaged
Vacuum hose cracked, holed, blocked, damaged or
disconnected
Hose or tube cracked, holed, damaged or loose
Fuel tank cracked, holed, or damaged
Charcoal canister cracked, holed or damaged
*1
*1: MIL lights up
*
2: MIL lights up or blinking
DI−48
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
DTC P0171 System too Lean (Fuel Trim)
DTC P0172 System too Rich (Fuel Trim)
CIRCUIT DESCRIPTION
”Fuel trim” refers to the feedback compensation value compared against the basic injection time. Fuel trim
includes short−term fuel trim and long−term fuel trim.
”Short−term fuel trim” is the short−term fuel compensation used to maintain the air−fuel ration at its ideal
theoretical value. The signal from the oxygen sensor indicates whether the air−fuel ratio is RICH or LEAN
compared to the ideal theoretical value, triggering a reduction in fuel volume if the air−fuel ratio is rich, and
an increase in fuel volume if it is lean.
”Long−term fuel trim” is overall fuel compensation carried out long−term to compensate for continual devi-
ation of the short−term fuel trim from the central value due to individual engine differences, wear over time
and changes in the usage environment.
If both the short−term fuel trim and long−term fuel trim are LEAN or RICH beyond a certain value, it is de-
tected as a malfunction and the MIL lights up.
DTC No.DTC Detecting ConditionTrouble Area
P0171
When the air fuel ratio feedback is stable after engine warning
up, the fuel trim is considerably in error on the RICH side
(2 trip detection logic)
Fuel line pressure
Injector blockage
Oxygen sensor malfunction
Manifold absolute pressure sensor
Engine coolant temp. sensor
P0172
When the air fuel ratio feedback is stable after engine warning
up, the fuel trim is considerably in error on the LEAN side
(2 trip detection logic)
Fuel line pressure
Injector blockage, leak
Oxygen sensor malfunction
Manifold absolute pressure sensor
Engine coolant temp. sensor.
HINT:
When DTC P0171 is recorded, the actual air−fuel ratio is on the LEAN side. When DTC P0172 is re-
corded, the actual air−fuel ratio is on the RICH side.
If the vehicle runs out of fuel, the air−fuel ratio is LEAN and DTC P0171 is detected. The MIL then
comes on.
If the total of the short−term fuel trim value and long−term fuel trim value is within ±25 %, the system
is functioning normally.
INSPECTION PROCEDURE
1 Check air induction system (See page SF−1).
NG Repair or replace.
OK
DI3ZN−01
− DIAGNOSTICSENGINE
DI−49
1996 RAV4 (RM447U)
2 Check for oxygen sensor data.
PREPARATION:
(a) Connect the OBDII scan tool or TOYOTA hand−held tester to the DLC3.
(b) Warm up engine to normal operating temperature.
CHECK:
Read the oxygen sensor output voltage and short−term fuel trim.
RESULT:
PatternOxygen sensor output voltageShort−term fuel trim
1Lean condition (Changes at 0.55 V or less)Changes at about +20 %
2Rich condition (Changes at 0.35 V or more)Changes at about −20 %
3Except 1 and 2
3 Check for oxygen sensor
(See page DI−42).
1, 2
3 Check fuel pressure (See page SF−5).
NG Check and repair fuel pump, pressure regulator,
fuel pipe line and filter (See page SF−1).
OK
4 Check injector injection (See page SF−21).
NG Replace injector.
OK
5 Check manifold absolute pressure sensor and engine coolant temp. sensor
(See page DI−21, DI−29).
NG Repair or replace.
OK
− 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
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.