1996 TOYOTA RAV4 fuel

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).

FI7081
Waveform of oxygen sensor
before catalystNormal
catalystWaveform of oxygen sensor
after catalyst
− DIAGNOSTICSENGINE
DI−73
1996 RAV4 (RM447U)
DTC P0420 Catalyst System Efficiency Below Threshold
CIRCUIT DESCRIPTION
The ECM compares the waveform of the oxygen sensor located before the catalyst with the waveform of
the oxygen sensor located after the catalyst to determine whether or not catalyst performance has deterio-
rated.
Air−fuel ratio feedback compensation keeps the waveform of the oxygen sensor before the catalyst repeat-
edly changing back and forth from rich to lean.
If the catalyst is functioning normally, the waveform of the oxygen sensor after the catalyst switches back
and forth between rich and lean much more slowly than the waveform of the oxygen sensor before the cata-
lyst.
But when both wavaforms change at a similar rate, it indicates that catalyst performance has deteriorated.
DTC NoDTC Detecting ConditionTrouble Area
P0420
After the engine and the catalyst are warmed up, and while the
vehicle is driven within the set vehicle and engine speed range,
the waveforms of the oxygen sensors (bank 1 sensor 1 and
bank 1 sensor 2) have the same amplitude
(2 trip detection logic)
Front TWC (front catalyst) and TWC w/pipe (rear catalyst)
Oxygen sensor
DI3ZV−01

(2) (1)
(5)
S00043
ECM
VSV
for EVAP
Fuel Tank
Charcoal CanisterVSV for Vapor
Pressure SensorVapor Pressure
Sensor
(4)
(3) DI−76
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
DTC P0440 Evaporative Emission Control System
Malfunction
CIRCUIT DESCRIPTION
The vapor pressure sensor and VSV for vapor pressure sensor are used to detect abnormalities in the evap-
orative emission control system.
The ECM decides whether there is an abnormality in the evaporative emission control system based on the
vapor pressure sensor signal.
DTC P0440 is recorded by the ECM when evaporative emissions leak from the components within the dotted
line in fig. 1 below, or when the vapor pressure sensor malfunctions.
DTC No.DTC Detecting ConditionTrouble Area
P0440
The fuel tank pressure is atmospheric pressure after the ve-
hicle is driven for 20 min.
(2 trip detection logic)
Vapor pressure sensor
Fuel tank cap incorrectly installed
Fuel tank cap cracked or damaged
Vacuum hose cracked, holed, blocked, damaged or discon-
nected ( (1) or (2) in fig. 1 ) ( (3) in fig. 1 )
Fuel tank cranked, holed or damaged
Charcoal canister cracked, holed or damaged
DI3ZW−01

S02388
6
66
6 3
15
2
1J 1E21J/B No.1 From
BatteryVaper Pressure Sensor
E5
E5
E5
E4
E58 229
7 1
EA1
B−R
B−O
11Fuse Block
From
IG SwitchVSV
(for Vapor
Pressure Sensor) VSV
(for EVAP)VC
PTNK
E2
EVP
TPCE01
E01 5V ECM
E1
B−R
1P
2 1
B−R BRL−Y Y
1 2 3
R/B No.6
2
B−R
W−B2
EA 10
IGN R−W
EFI Main Relay
R−W A
A
W−B
J1 Junction
Connector B−O
− DIAGNOSTICSENGINE
DI−77
1996 RAV4 (RM447U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
If DTC P0441, P0446 or P0450 is output after DTC P0440, first troubleshoot DTC P0441, P0446 or
P0450. If no malfunction is detected, troubleshoot DTC P0440 next.
Ask the customer whether, after the MIL came on, the customer found the fuel tank cap loose and tight-
ened it. Also ask the customer whether the fuel tank cap was loose when refuelling.
If the fuel tank cap was loose, it was the cause of the DTC. If the fuel tank cap was not loose or if the
customer was not sure if it was loose, troubleshoot according to the following procedure.

S00046
DI−78
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
1 Check whether the hoses close to the fuel tank have been modified, and check
whether there are signs of any accident near the fuel tank or charcoal canister.
CHECK:
Check for cracks, deformation and loose connection of the fol-
lowing parts.
Fuel tank
Charcoal canister
Fuel tank filler pipe
Hoses and tubes around the fuel tank and charcoal
canister
NG Repair or replace.
OK
2 Check that the fuel tank cap is TOYOTA genuine parts.
NG Replace to TOYOTA genuine parts.
OK
3 Check that the fuel tank cap is correctly installed.
NG Correctly install the fuel tank cap.
OK
4 Check the fuel tank cap (See page EC−5).
NG Replace fuel tank cap.
OK

− DIAGNOSTICSENGINE
DI−79
1996 RAV4 (RM447U)
5 Check the filler neck for damage.
PREPARATION:
Remove the fuel tank cap.
CHECK:
Visually inspect the filler neck for damage.
NG Replace the filler neck.
OK
6 Check the vacuum hoses between vapor pressure sensor and VSV for vapor
pressure sensor, and VSV for vapor pressure sensor and charcoal canister.
CHECK:
(a) Check that the vacuum hose is connected correctly.
(b) Check the vacuum hose for looseness and disconnection.
(c) Check the vacuum hose for cracks, hole and damage.
NG Repair or replace.
OK
7 Check the hose and tube between fuel tank and charcoal canister.
CHECK:
(a) Check for proper connection of the fuel tank and fuel evap pipe (See page SF−1), fuel evap pipe and
fuel tube under the floor, fuel tube under the floor and charcoal canister.
(b) Check the hose and tube for cracks, hole and damage.
NG Repair or replace.
OK
8 Check the charcoal canister for cracks, hole and damage (See page EC−5).
NG Replace charcoal canister.
OK

S00048
Pressure
− DIAGNOSTICSENGINE
DI−81
1996 RAV4 (RM447U)
NG Repair or replace harness or connector.
OK
Replace vapor pressure senor.
12 Check the fuel tank for cracks and damage.
PREPARATION:
(a) Disconnect the vacuum hose from charcoal canister.
(b) Correctly install the fuel tank cap.
(c) Apply a pressure of 5 kPa (0.05 kgf/cm
2, 0.71 psi) to the
fuel tank.
CHECK:
Check whether the pressure is maintained after 1 minute.
OK:
Pressure applied to the fuel tank is maintained.
NG Replace fuel tank.
OK
It is likely that the vehicle user did not properly close the fuel tank cap. Please explain to the cus-
tomer how to properly install the fuel tank cap.

S00044
ECM
VSV
for EVAP
Fuel Tank Charcoal CanisterVSV for Vapor
Pressure SensorVapor Pressure
Sensor
fig.1 (5)(4)(1)
(2)
(3) (6)
DI−82
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
DTC P0441 Evaporative Emission Control System
Incorrect Purge Flow
DTC P0446 Evaporative Emission Control System Vent
Control Malfunction
CIRCUIT DESCRIPTION
The vapor pressure sensor and VSV for vapor pressure sensor are used to detect abnormalities in the evap-
orative emission control system.
The ECM decides whether there is an abnormality in the evaporative emission control system based on the
vapor pressure sensor signal.
DTC P0441 and P0446 are recorded by the ECM when evaporative emissions leak from the components
within the dotted line in fig. 1 below, or when there is a malfunction in either the VSV for EVAP, the VSV for
vapor pressure sensor, or in the vapor pressure sensor itself.
DI3ZX−01