1996 TOYOTA RAV4 coolant

A00398
Engine Coolant
Temp. Sensor
E2
THW
5V ECM
E1
ON
E5connector
DI−32
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
5 Check for short in harness or ECM.
PREPARATION:
(a) Remove side trim cover. (See page SF−61).
(b) Disconnect the E5 connector of ECM.
HINT:
Engine coolant temp. sensor connector is disconnected.
(c) Turn ignition switch ON.
CHECK:
Read temperature value on the OBDII scan tool or TOYOTA
hand−held tester.
OK:
Temperature value : − 40°C (− 40°F)
OK Repair or replace harness or connector.
NG
Check and replace ECM
(See page IN−30).

− DIAGNOSTICSENGINE
DI−33
1996 RAV4 (RM447U)
DTC P0116 Engine Coolant Temp. Circuit Range /
Performance Problem
CIRCUIT DESCRIPTION
Refer to Engine Coolant Temp. Circuit Malfunction on page DI−29.
DTC No.DTC Detecting ConditionTrouble Area
P0116
If THW < −7°C (19.4°F), 20 minutes or more after starting
engine, engine coolant temp. sensor value is 20°C (68°F) or
less
(2 trip detection logic)
Engine coolant temp. sensor
Cooling system
If THW  −7°C (19.4°F), 5 minutes or more after starting
engine, engine coolant temp. sensor value is 20°C (68°F) or
less
(2 trip detection logic)
INSPECTION PROCEDURE
HINT:
If DTC ”P0115” (Engine Coolant Temp. Circuit Malfunction) and ”P0116” (Engine Coolant Temp. Circuit
Range / Performance Problem) are output simultaneously, engine coolant temp. sensor circuit may be open.
Perform troubleshooting of DTC P0115 first.
1 Are there any other codes (besides DTC P0116) being output?
YES Go to relevant DTC chart.
NO
2 Check thermostat (See page CO−11).
NG Replace thermostat.
OK
Replace engine coolant temp. sensor
(See page SF−49).
DI3ZG−01

P25426
Throttle Position Sensor
4
E5
3
2L
1
BR L−R Y5V
VC
VTA
E2
E1 From Cruise
Control ECU1
11
9 E5
E5ECM
FI7052
− DIAGNOSTICSENGINE
DI−35
1996 RAV4 (RM447U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
If DTC P0105” (Manifold Absolute Pressure / Barometric Pressure Circuit Malfunction), ”P0110” (Intake Air
Temp. Circuit Malfunction), ”P0115” (Engine Coolant Temp. Circuit Malfunction), ”P0120” (Throttle / Pedal
Position Sensor / Switch ”A” Circuit Malfunction) are output simultaneously, E2 (sensor ground) may be
open.
1 Connect OBDII scan tool or TOYOTA hand−held tester and read the throttle valve
opening percentage.
PREPARATION:
(a) Connect the OBDII scan tool or TOYOTA hand−held tester to the DLC3.
(b) Turn ignition switch ON and OBDII scan tool or TOYOTA hand−held tester main switch ON.
CHECK:
Read the throttle valve opening percentage.
OK:
Throttle valveThrottle valve opening position
expressed as percentage
Fully openApprox. 70 %
Fully closedApprox. 10 %

FI6606FI7210A06619
Atmosphere
Flange
Platinum Electrode
Solid Electrolyte
(Zirconia Element)
Platinum Electrode
Coating (Ceramic)
Richer−air Fuel Ratio−Leaner Ideal Air−Fuel Mixture
Output Voltage
Cover
Exhaust Gas
− DIAGNOSTICSENGINE
DI−39
1996 RAV4 (RM447U)
DTC P0125 Insufficient Coolant Temp. for Closed Loop
Fuel Control
CIRCUIT DESCRIPTION
To obtain a high purification rate for the CO, HC and NOx components of the exhaust gas, a three−way cata-
lytic converter is used, but for the most efficient use of the three−way catalytic converter, the air−fuel ratio
must be precisely controlled so that it is always close to the stoichiometric air−fuel ratio.
The oxygen sensor has the characteristic whereby its output voltage changes suddenly in the vicinity of the
stoichiometric air−fuel ratio. This characteristic is used to detect the oxygen concentration in the exhaust
gas and provide feedback to the computer for control of the air−fuel ratio.
When the air−fuel ratio becomes LEAN, the oxygen concentration in the exhaust increases and the oxygen
sensor informs the ECM of the LEAN condition (small electromotive force: 0 V).
When the air−fuel ratio is RICHER than the stoichiometric air−fuel ratio the oxygen concentration in the ex-
haust gas is reduced and the oxygen sensor informs the ECM of the RICH condition (large electromotive
force: 1 V).
The ECM judges by the electromotive force from the oxygen sensor whether the air−fuel ratio is RICH or
LEAN and controls the injection time accordingly. However, if malfunction of the oxygen sensor causes out-
put of abnormal electromotive force, the ECM is unable to perform accurate air−fuel ratio control.
DTC No.DTC Detecting ConditionTrouble Area
P0125
After the engine is warmed up, oxygen sensor output does not
indicate RICH even once when conditions (a), (b), and (c)
continue for at least 1.5 minutes
(a) Engine speed: 1,500 rpm or more
(b) Vehicle speed: 40 ∼ 100 km/h (25 ∼ 62 mph)
(c) Throttle valve does not fully closed
Open or short in oxygen sensor circuit
oxygen sensor
HINT:
After confirming DTC P0125 use the OBDII scan tool or TOYOTA hand−held tester to confirm voltage output
of oxygen sensor from ”CURRENT DATA”.
If voltage output of oxygen sensor is 0 V, oxygen sensor circuit may be open or short.
DI3ZJ−01

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−45
1996 RAV4 (RM447U)
DTC P0133 Oxygen Sensor Circuit Slow Response
(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
P0133
Response time for the oxygen sensor’s voltage output to
change from rich to lean, or from lean to rich, is 1 sec. or more
during idling after the engine is warmed up
(2 trip detection logic)
Oxygen sensor
HINT:
Sensor 1 refers to the sensor closer to the engine body.
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P0133) being output?
YES Go to relevant DTC chart.
NO
Replace oxygen sensor.
DI3ZL−01

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

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