1996 TOYOTA RAV4 IAC

− 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.

DI−16
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U) DTC No.
(See Page)
Detection ItemTrouble AreaMILMemory
P0441
(DI−82)Evaporative Emission Control
System Incorrect Purge Flow
Open or short in VSV circuit for vapor pressure sensor
VSV for vapor pressure sensor
Open or short in vapor pressure sensor circuit
Vapor pressure sensor
Open or short in VSV circuit for EVAP
VSV for EVAP
Vacuum hose cracked, holed, blocked, damaged or
disconnected
Charcoal canister cracked, holed or damaged
 *1
P0446
(DI−82)Evaporative Emission Control
System Vent Control
Malfunction
P0450
(DI−92)Evaporative Emission Control
System Pressure Sensor
MalfunctionOpen or short in vapor pressure sensor circuit
Vapor pressure sensor
ECM
 *1
P0500
(DI−94)Vehicle Speed Sensor
Malfunction
Open or short in vehicle speed sensor circuit
Vehicle speed sensor
Combination meter
ECM
 *1
P0505
(DI−97)Idle Control System Malfunction
IAC valve is stuck or closed
Open or short in IAC valve circuit
Open or short AC1 single circuit
Air intake (hose loose)
 *1
*1: MIL lights up
MANUFACTURER DEFINED
DTC No.
(See Page)Detection ItemTrouble AreaMILMemory
P1300
(DI−100)Ignition Circuit Malfunction
Open or short in IGF or IGT circuit from igniter to ECM
Igniter
ECM
 *1
P1500
(DI−105)Starter Signal Circuit Malfunction
Open or short in starter signal circuit
Open or short in ignition switch or starter relay circuit
ECM
 *1
P1600
(DI−108)ECM BATT MalfunctionOpen in back up power source circuit
ECM *1
P1780
(DI−11 0)Park / Neutral Position Switch
MalfunctionShort in park / neutral position switch circuit
Park / neutral position switch
ECM
 *1
*1: MIL lights up

P01559
From
Air
CleanerThrottle valve
Signals
Valve IAC Valve
To Cylinders ECM
Intake
Air
Chamber
− DIAGNOSTICSENGINE
DI−97
1996 RAV4 (RM447U)
DTC P0505 Idle Control System Malfunction
CIRCUIT DESCRIPTION
The rotary solenoid type IAC valve is located on the throttle
body and intake air bypassing the throttle valve is directed to
the IAC valve through a passage.
In this way the intake air volume bypassing the throttle valve is
regulated, controlling the engine speed.
The ECM operates only the IAC valve to perform idle−up and
provide feedback for the target idling speed.
DTC No.DTC Detecting ConditionTrouble Area
P0505Idle speed continues to vary greatly from the target speed
(2 trip detection logic)
IAC valve is stuck or closed
Open or short in IAC valve circuit
Open or short IAC signal circuit
Air intake (hose loose)
DI400−01

S02401
6
66 6 5
2 13R/B No.6
From Battery
Fuse Block
1J
1E
B−O11 1
2
From
IG SwitchECM
ISCO
ISCC E4
E4 B−L
B−Y10
9 IAC Valve
EA12
2
B−R B−R
W−B W−B
EA J1
Junction Connector
AA EFI Main Relay R−W
IGNE01
E01
J/B No.13 1
10 B−O
DI−98
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check air induction system (See page EC−5).
NG Repair or replace.
OK
2 Check A/C signal circuit (See page AC−64).
NG Repair or replace.
OK
3 Check voltage between terminals ISCO, ISCC of ECM connector and body
ground.

A00416
ISCO
(+)
E4
ConnectorISCC
(+)ON
− DIAGNOSTICSENGINE
DI−99
1996 RAV4 (RM447U)
PREPARATION:
(a) Remove side trim cover (See page SF−61).
(b) Disconnect the E4 connector of ECM.
(c) Turn ignition switch ON.
CHECK:
Measure voltage between terminals ISCO, ISCC of ECM con-
nector and body ground.
OK:
Voltage: 9 − 14 V
OK Go to step 5.
NG
4 Check IAC valve (See page SF−34).
NG Replace IAC valve.
OK
Check for open and short in harness and con-
nector between R/B No.6 and IAC valve, IAC
valve and ECM (See page IN−30).
5 Check operation of the IAC valve (See page SF−34).
NG Repair or replace IAC valve.
OK
Check and replace ECM (See page IN−30).

EM−2
− ENGINE MECHANICALCO/HC
1996 RAV4 (RM447U)
6. TROUBLESHOOTING
If the CO/HC concentration does not comply with regulations,
troubleshoot in the order given below.
(a) Check the oxygen sensor operation (See page DI−42).
(b) See the table below for possible causes, then inspect and
correct the applicable causes if necessary.
HCCOProblemsCauses
HighNormalRough idle4. Faulty ignitions:
Incorrect timing
Fouled, shorted or improperly gapped plugs
Open or or crossed high−tension cords
Cracked distributor cap
5. Incorrect valve clearance
6. Leaky EGR valve
7. Leaky intake and exhaust valves
8. Leaky cylinder
HighLowRough idle
(Fluctuating HC reading)1. Vacuum leaks:
PCV hose
EGR valve
Intake manifold
Throttle body
IAC valve
Brake booster line
2. Lean mixture causing misfire
HighHighRough idle
(Black smoke from exhaust)1. Restricted air filter
2. Faulty SFI system:
Faulty pressure regulator
Clogged fuel return line
Defective ECT sensor
Defective IAT sensor
Faulty ECM
Faulty injector
Faulty throttle position sensor
MAP sensor

EM0EK−01
EM−12
− ENGINE MECHANICALIDLE SPEED
1996 RAV4 (RM447U)
IDLE SPEED
INSPECTION
1. INITIAL CONDITIONS
(a) Engine at normal operating temperature
(b) Air cleaner installed
(c) All pipes and hoses of air induction system connected
(d) All vacuum lines properly connected
(e) SFI system wiring connectors fully plugged
(f) All operating accessories switched OFF
(g) Ignition timing check correctly
(h) Transmission in neutral position
(i) Air conditioning switched OFF
2. CONNECT TOYOTA HAND−HELD TESTER OR OBD II SCAN TOOL (See page EM−11)
3. INSPECT IDLE SPEED
(a) Race the engine speed at 2,500 rpm for approx. 90 seconds.
(b) Check the idle speed.
Idle speed (w/ Cooling fan OFF): 750 ± 50 rpm
If the idle speed is not as specified, check the IAC valve and air intake system.
4. DISCONNECT TOYOTA HAND−HELD TESTER OR OBD II SCAN TOOL

S01823
Oxygen Sensor
(Bank 1 Sensor 1)
Oxygen Sensor (Bank 1 Sensor 2)
P03152
S01368
S01365
S01594
EM−34
− ENGINE MECHANICALCYLINDER HEAD
1996 RAV4 (RM447U)
10. REMOVE OXYGEN SENSOR (BANK 1 SENSOR 1)
FROM EXHAUST MANIFOLD
11. REMOVE OXYGEN SENSOR (BANK 1 SENSOR 2)
FROM FRONT TWC
12. SEPARATE EXHAUST MANIFORD AND FRON TWC
(a) Remove the 5 bolts and lower manifold heat insulator.
(b) Remove the 8 bolts and 2 TWC heat insulators.
(c) Remove the 3 bolts, 2 nuts, TWC, gasket retainer and
cushion.
13. DISCONNECT OIL PRESSURE SWITCH CONNECTOR
14. REMOVE WATER OUTLET
(a) Disconnect the ECT sensor connector.
(b) Disconnect the ECT sender gauge connector.
(c) Disconnect the radiator hose from the water outlet.
(d) Disconnect the water bypass pipe hose from the water
outlet.
(e) Disconnect the heater water hose from the water outlet.
(f) Remove the 2 nuts, water outlet and gasket.
15. REMOVE WATER BYPASS PIPE
(a) Remove the bolt, 2 nuts and oil cooler heat protector.
(b) Disconnect the IAC valve water bypass hose from the wa-
ter bypass pipe.
(c) Disconnect the heater water hose from the water bypass
pipe.
(d) Disconnect the 2 oil cooler water bypass hoses from the
oil cooler.
(e) Remove the nut and disconnect the wire protector.
(f) Remove the 2 bolts and 2 nuts.
(g) Disconnect the water bypass pipe from the water pump
cover, and remove the water bypass pipe.
(h) Remove the gasket and O−ring.
16. REMOVE THROTTLE BODY (See page SF−30)