1996 TOYOTA RAV4 Service Repair Manual

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).

S07638
IG1
1H 1DI4I4
E4
E43 20
EA17
IG111
2221
20 8
1412
67
2
W B−WB−RB−R B−W
B−W
B−W
B−W
L−Y 4
53
2
1 Tr2
Igniter To Tachometer Distributor
BatteryFusible Link BlockR/B No.2
B−R IG Switch 4ECM
IGT
IGF5V
Tr1
AM2B
B−Y
Ignition Coil
J/B No.1
MAIN DI−100
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
DTC P1300 Igniter Circuit Malfunction
CIRCUIT DESCRIPTION
This ECM determines the ignition timing, turns on Tr1 at a predetermined angle (°CA) before the desired
ignition timing and outputs an ignition signal (IGT) ”1” to the igniter.
Since the width of the IGT signal is constant, the dwell angle control circuit in the igniter determines the time
the control circuit starts primary current flow to the ignition coil based on the engine rpm and ignition timing
one revolution ago, that is, the time the Tr
2 turns on.
When it reaches the ignition timing, the ECM turns Tr
1 off and outputs the IGT signal ”O”.
This turns Tr
2 off, interrupting the primary current flow and generating a high voltage in the secondary coil
which causes the spark plug to spark. Also, by the counter electromotive force generated when the primary
current is interrupted, the igniter sends an ignition confirmation signal (IGF) to the ECM.
The ECM stops fuel injection as a fail safe function when the IGF signal is not input to the ECM.
DTC No.DTC Detecting ConditionTrouble Area
P1300No IGF signal to ECM for 8 consecutive IGT signals during
engine running.Open or short in IGF or IGT circuit from igniter to ECM
Igniter
ECM
WIRING DIAGRAM
DI401−01

A00417
IGF
(+)
ON
− DIAGNOSTICSENGINE
DI−101
1996 RAV4 (RM447U)
INSPECTION PROCEDURE
1 Check spark plug and spark (See page IG−1).
NG Go to step 4.
OK
2 Check for open and short in harness and connector in IGF signal circuit between
ECM and igniter (See page IN−30).
NG Repair or replace harness or connector.
OK
3 Disconnect igniter connector and check voltage between terminal IGF of ECM
connector and body ground.
PREPARATION:
(a) Disconnect igniter connector.
(b) Remove side trim cover (See page SF−61).
(c) Turn ignition switch ON.
CHECK:
Measure voltage between terminal IGF of ECM connector and
body ground.
OK:
Voltage: 4.5 − 5.5 V
OK Replace igniter.
NG
Check and replace ECM (See page IN−30).

BE6653P23732A06621
START
IGT
(+)
FI6680
IGT/IGF signal waveform
IGT
0 V
IGF
0 V
10 m sec./Division (Idling)2 V/Division
DI−102
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
4 Check for open and short in harness and connector in IGT signal circuit between
ECM and igniter (See page IN−30).
NG Repair or replace harness or connector.
OK
5 Check voltage between terminal IGT of ECM connector and body ground.
PREPARATION:
Remove side trim cover (See page SF−61).
CHECK:
Measure voltage between terminal IGT of ECM connector and
body ground when engine is cranked.
OK:
Voltage: More than 0.1 V and less than 4.5 V
Reference:
INSPECTION USING OSCILLOSCOPE
During idling, check waveform between terminal IGT and E1 of
ECM.
HINT:
The correct waveforms are as shown.
NG Check and replace ECM (See page IN−30).
OK

BE6653P23732A06621
START
IGT
(+)
BE6653P23909A07402
ON
3 (+) START
− DIAGNOSTICSENGINE
DI−103
1996 RAV4 (RM447U)
6 Disconnect igniter connector and check voltage between terminal IGT of ECM
connector and body ground.
PREPARATION:
(a) Disconnect the igniter connector.
(b) Remove side trim cover (See page SF−61).
CHECK:
Measure voltage between terminal IGT of ECM connector and
body ground when engine is cranked.
OK:
Voltage: More than 0.1 V and less than 4.5 V
OK Replace igniter.
NG
7 Check voltage between terminal 3 of igniter connector and body ground.
PREPARATION:
Disconnect the igniter connector.
CHECK:
Measure voltage between terminal 3 of igniter connector and
body ground, when ignition switch is turned to ”ON” and
”START” position.
OK:
Voltage: 9 − 14 V
NG Check and repair igniter power source circuit.
OK
8 Check for open and short in harness and connector between ignition switch and
ignition coil, ignition coil and igniter (See page IN−30).
NG Repair or replace harness or connector.
OK

DI−104
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
9 Check ignition coil (See page IG−1).
NG Replace ignition coil.
OK
Replace igniter.