1996 TOYOTA RAV4 Engine

DI−64
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
3 Inspect sensor installation.
NG Tighten the sensor.
OK
Check and replace ECM (See page IN−30).

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

(7)
(5) (4)(6)
(3)
(2)
(1)
P20769
Vehicle Speed
70 − 90 km/h
(43 − 56 mph)
Idling
IG SW OFF
Warm up
3 − 5 mins2 mins 3 − 5 mins 2 mins Time
DI−66
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
SYSTEM CHECK DRIVING PATTERN
(1) Connect the OBDII scan tool or TOYOTA hand−held tester to the DLC3.
(2) Start and warm it up the engine with all accessories switched OFF.
(3) Run the vehicle at 70 − 90 km/h (43 − 56 mph) for 3 minutes or more.
(4) Idle the engine for about 2 minutes.
(5) Stop at safe place and turn the ignition switch OFF.
(6) Start the engine and do steps (3) and (4) again.
(7) Check the ”READINESS TESTS” mode on the OBDII scan tool or TOYOTA hand−held tester. If ”COMPL”
is displayed and the MIL does not light up, the system is normal. If ”INCMPL” is displayed and the MIL does
not light up, run the vehicle again and check it.
HINT:
”INCMPL” is displayed when either condition (a) or (b) exists.
The system check is incomplete.
There is malfunction in the system.
If there is a malfunction in the system, the MIL will light up after step (2) to (6) above are done.
INSPECTION PROCEDURE
HINT:
If DTC ”P0150” and / or ”P0106” and ”P0401” are output simultaneously, perform troubleshooting or
DTC ”P0105” first.
If DTC ”P0401” and ”P0402” are output simultaneously, perform troubleshooting of DTC ”P0402” first.

A00407
System: (OFF) System: (ON)Air
GGAir
EE
Air Filter
− DIAGNOSTICSENGINE
DI−67
1996 RAV4 (RM447U)
TOYOTA hand−held tester
1 Check the connection of the vacuum hose, EGR hose (See page EC−5).
NG Repair or replace.
OK
2 Check the VSV for EGR.
PREPARATION:
Select the ACTIVE TEST mode on the TOYOTA hand−held tes-
ter.
CHECK:
Check operation of VSV, when it is operated by the TOYOTA
hand−held tester.
OK:
EGR system is OFF:
Air from pipe E is flowing out through the air filter.
EGR system is ON:
Air from pipe E is flowing out pipe G.
OK Go to step 4.
NG
3 Check operation of the VSV for EGR (See page SF−43).
NG Replace VSV for EGR.
OK
Check for open and short in harness and con-
nector between R/B No.6 and ECM
(See page IN−30).

DI−68
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
4 Check EGR vacuum modulator (See page EC−8).
NG Repair or replace.
OK
5 Check EGR valve (See page EC−8).
NG Repair or replace.
OK
6 Check manifold absolute pressure sensor (See page DI−21).
NG Repair or replace.
OK
Check and replace ECM (Se page IN−30).
OBDII scan tool (excluding TOYOTA hand−held tester)
1 Check the connection of vacuum hose, EGR hose (See page EC−5).
NG Repair or replace.
OK

A00408
ON
EGR
(+)ONOFFE4 connector
Air
(ON) (OFF) G
Air FilterE
GEAir
− DIAGNOSTICSENGINE
DI−69
1996 RAV4 (RM447U)
2 Check the VSV for EGR.
PREPARATION:
(a) Remove side trim cover (See page SF−62).
(b) Disconnect the E4 connector of ECM.
(c) Turn ignition switch ON.
CHECK:
Check VSV function.
(1) Connect between terminal EGR of ECM connector
and body ground. (ON)
(2) Disconnect between terminal EGR of ECM connec-
tor and body ground. (OFF)
OK:
(1) VSV is ON:
Air from pipe E is Flowing out through the air filter.
(2) VSV is OFF:
Air from pipe E is flowing out pipe G.
OK Go to step 4.
NG
3 Check operation of the VSV for EGR (See page SF−43).
NG Replace VSV for EGR.
OK
Check for open and short in harness and con-
nector between R/B No.6 and ECM
(See page IN−30).

DI−70
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
4 Check EGR vacuum modulator (See page EC−8).
NG Repair or replace.
OK
5 Check EGR valve (See page EC−8).
NG Repair or replace.
OK
6 Check manifold absolute pressure sensor (See page DI−21).
NG Repair or replace.
OK
Check and replace ECM
(See page IN−30).

− DIAGNOSTICSENGINE
DI−71
1996 RAV4 (RM447U)
DTC P0402 Exhaust Gas Recirculation Flow Excessive
Detected
CIRCUIT DESCRIPTION
Refer to Exhaust Gas Recirculation Flow Insufficient Detected on page DI−65.
DTC No.DTC Detecting ConditionTrouble Area
P0402
After the engine is warmed up, conditions (a) and (b) continue
(a) The intake manifold absolute pressure is larger than the
value calculated by the ECM while the EGR system is ON.
(b) Misfiring is detected during idling
(2 trip detection logic)EGR valve stuck open
Vacuum or EGR hose is connected to wrong post
Manifold absolute pressure sensor
ECM
See DTC P0140 for System Check Driving Pattern and Wiring Diagram.
INSPECTION PROCEDURE
HINT:
If DTC ”P0105” and / or ”P0106” and ”P0402” are output simultaneously, perform troubleshooting of
DTC ”P0105” first.
If DTC ”P0401” and ”P0402” are output simultaneously, perform troubleshooting of DTC ”P0402” first.
1 Check the connection of the vacuum hose, EGR hose (See page EC−5).
NG Repair or replace.
OK
2 Check EGR valve (See page EC−8).
NG Repair or replace.
OK
3 Check the VSV for EGR * .
* If you have TOYOTA hand−held tester, see page DI−65, step 2.
If you have no TOYOTA hand−held tester, see page DI−65, step 2.
OK Go to step 5.
NG
DI3ZU−01