check engine TOYOTA RAV4 1996 Service Workshop Manual

A01666
Vehicle speed
50 − 65 km/h
(31 − 40 mph)
Idling
IG SW OFF
1 − 3 min.
1 min.
Time (1)(2)(4)
(5) (3) DI−42
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
DTC P0130 Oxygen Sensor Circuit Malfunction
(Bank 1 Sensor 1)
CIRCUIT DESCRIPTION
Refer to ”Insufficient Coolant Temp. for Closed Loop Fuel Control” on page DI−39.
DTC No.DTC Detecting ConditionTrouble Area
P0130
Voltage output of oxygen sensor remains at 0.35 V or more,
0.55 V or less, during idling after the engine is warmed up
(2 trip detection logic)Oxygen sensor
Fuel trim malfunction
HINT:
Sensor 1 refers to the sensor closer to the engine body.
The oxygen sensor’s output voltage and the short−term fuel trim value can be read using the OBDII scan
tool or TOYOTA hand−held tester.
WIRING DIAGRAM
Refer to page DI−39 for the WIRING DIAGRAM.
CONFIRMATION DRIVING PATTEN
(1) Connect the TOYOTA hand−held tester to the DLC3.
(2) Switch the TOYOTA hand−held tester from normal mode to check mode (See page DI−3).
(3) Start the engine and warm it up with all accessory switches OFF.
(4) Drive the vehicle at 50 − 65 km/h (31 − 40 mph) for 1 − 3 minutes to warm up the oxygen sensor.
(5) Idle the engine for 1 minute.
HINT:
If a malfunction exists, the MIL will light up during step (5).
NOTICE:
If the conditions in this test are not strictly followed, detection of the malfunction will not be possible.
If you do not hove a TOYOTA hand−held tester, turn the ignition switch OFF after performing steps
(3) to (5), then perform steps (3) to (5) again.
DI3ZK−01

− DIAGNOSTICSENGINE
DI−43
1996 RAV4 (RM447U)
INSPECTION PROCEDURE
1 Check for open and short in harness and connector between ECM and oxygen
sensor (See page IN−30).
NG Repair or replace harness or connector.
OK
2 Check for oxygen sensor date.
PREPARATION:
(a) Connect the OBDII scan tool or TOYOTA hand−held tester to the DLC 3.
(b) Warm up engine to normal operation 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
1, 2 Check fuel trim system (See page DI−48).
3

A00292
O K N G N G N G
1 V
0.55 V
0.35 V
0 V
DI−44
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
3 Check the output voltage of oxygen sensor during idling.
PREPARATION:
Warm up the oxygen sensor with the engine at 2,500 rpm for approx. 90 sec.
CHECK:
Use the OBDII scan tool or TOYOTA hand−held tester read the output voltage of the oxygen sensor during
idling.
OK:
Oxygen sensor output voltage:
Alternates repeatedly between approx. 0.35 V and approx. 0.55 V (See the following table.)
OK Perform confirmation driving pattern
(See page DI−42).
NG
Replace oxygen sensor.

DI−46
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
DTC P0136 Oxygen Sensor Circuit Malfunction
(Bank 1 Sensor 2)
CIRCUIT DESCRIPTION
Refer to ”Insufficient Coolant Temp. for Closed Loop Fuel Control” on page DI−39.
DTC No.DTC Detecting ConditionTrouble Area
P0136
Voltage output of the oxygen sensor (bank 1 sensor 2)
remains at 0.4 V or more or 0.5 V or less when the vehicle is
driven at 40km/h (25 mph) or more after the engine is warmed
up
(2 trip detection logic)
Oxygen sensor
HINT:
Sensor 2 refers to the sensor farther away from the engine body.
WIRING DIAGRAM
Refer to page DI−39 for the WIRING DIAGRAM.
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P0136) being output?
YES Go to relevant DTC chart.
NO
2 Check for open and short in harness and connector between ECM and oxygen
sensor (See page IN−30).
NG Repair or replace harness or connector.
OK
DI3ZM−01

− DIAGNOSTICSENGINE
DI−47
1996 RAV4 (RM447U)
3 Check the output voltage of oxygen sensor (bank 1 sensor 2).
PREPARATION:
(a) Connect the OBDII scan tool or TOYOTA hand−held tester to the DLC 3.
(b) Warm up engine to normal operating temperature.
CHECK:
Read the output voltage of oxygen sensor (Bank 1 Sensor 2) when engine is suddenly raced.
HINT:
Perform quick racing to 4,000 rpm for 3 mins using accelerator pedal.
OK:
Oxygen sensor output voltage: Alternates from 0.4 V or less to 0.5 V or more.
OK Check that each connector is properly con-
nected.
NG
Replace oxygen sensor.

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

DI−50
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
6 Check for spark and ignition (See page IG−1).
NG Repair or replace.
OK
Check and replace ECM
(See page IN−30).

IG0317IG0151P25066A06618
1.1 − 1.3 mm
(0.043 − 0.051 in.)
A00404
”10 (+)
#30 (+)#40 (+) ON
#20 (+)
− DIAGNOSTICSENGINE
DI−53
1996 RAV4 (RM447U)
INSPECTION PROCEDURE
1 Check spark plug and spark of misfiring cylinder.
PREPARATION:
(a) Disconnect the high−tension cord from spark plug.
(b) Remove spark plug.
CHECK:
(a) Check the carbon deposits on electrode.
(b) Check electrode gap.
OK:
(1) No large carbon deposit present.
Not wet with gasoline or oil.
(2) Electrode gap: 1.1 − 1.3 mm (0.043 − 0.051 in.)
PREPARATION:
(a) Install the spark plug to the high − tension cord.
(b) Disconnect injector connector.
(c) Ground 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.
OK:
Spark jumps across electrode gap.
NG Replace or check ignition system (See page
IG−1).
OK
2 Check voltage of ECM terminal for injector of failed cylinder.
PREPARATION:
(a) Remove side trim cover (See page SF−61).
(b) Turn ignition switch ON.
CHECK:
Measure voltage between applicable terminal of ECM connec-
tor and body ground.
OK:
Voltage: 9 − 14 V
OK Go to step 4
NG

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).