TOYOTA RAV4 1996 Service Repair Manual

A00396
Engine Coolant
Temp. Sensor
E5E2
THW
5V
94ECM
E5
E1
12
ON
THWE2
A00397
Engine Coolant
Temp. Sensor
E5E2
THW
5V
94ECM
E5
E1
ON
− DIAGNOSTICSENGINE
DI−31
1996 RAV4 (RM447U)
3 Check for open in harness or ECM.
PREPARATION:
(a) Remove side trim cover. (See page SF−61).
(b) Connect between terminals THW and E2 of ECM connec-
tor.
HINT:
Engine coolant temp. sensor connector is disconnected. Be-
fore checking, do a visual and contact pressure check for the
ECM connector (See page IN−30).
(c) Turn ignition switch ON.
CHECK:
Read temperature value on the OBDII scan tool or TOYOTA
hand−held tester.
OK:
Temperature value: 140°C (284°F) or more
OK Open in harness between terminals E2 or THW,
repair or replace harness.
NG
Confirm good connection at ECM.
If OK, replace ECM.
4 Check for short in harness and ECM.
PREPARATION:
(a) Disconnect the engine coolant temp. sensor connector.
(b) 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 Replace engine coolant temp. sensor.
NG

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

P24296
Throtttle Position
SensorECM
VC
VTA
E2 DI−34
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
DTC P0120 Throttle/Pedal Position Sensor/Switch ”A”
Circuit Malfunction
CIRCUIT DESCRIPTION
The throttle position sensor is mounted in the throttle body and
detects the throttle valve opening angle. When the throttle valve
is fully closed, a voltage of approximately 0.3 V − 0.8 V is ap-
plied to terminal VTA of the ECM. The voltage applied to the ter-
minal VTA of the ECM increases in proportion to the opening
angle of the throttle valve and becomes approximately 3.2 − 4.9
V when the throttle valve is fully opened. The ECM judges the
vehicle driving conditions from this signal input from terminal
VTA, and uses them as one of the conditions for deciding the
air−fuel ration correction, power increases correction and fuel−
cut control etc.
DTC No.DTC Detecting ConditionTrouble Area
P0120
Condition (a) or (b) continues
(a) VTA < 0.1 V
(b) VTA > 4.9 VOpen or short in throttle position sensor circuit
Throttle position sensor
ECM
HINT:
After confirming DTC P0120 use the OBDII scan tool or TOYOTA hand−held tester to confirm the throttle
valve opening percentage.
Throttle Valve opening position expressed as percentageTrouble AreaThrottle Valve fully closedThrottle Valve fully open
0 %0 %VC line open
VTA line open or short
100 %100 %E2 line open
DI3ZH−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 %

BE6653P23908
A06617
ON
A00400
ON
VTA
(+)E2
(−)
DI−36
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
OK Check for intermittent problems
(See page DI−3).
NG
2 Check voltage between terminal VC of wire harness side connector and body
ground.
PREPARATION:
(a) Disconnect the throttle position sensor connector.
(b) Turn ignition ON.
CHECK:
Measure voltage between terminal VC of wire harness side
connector and body ground.
OK:
Voltage: 4.5 − 5.5 V
NG Go to step 5.
OK
3 Check throttle position sensor (See page SF−31).
NG Replace throttle position sensor.
OK
4 Check voltage between terminals VTA and E2 of ECM connector.
PREPARATION:
(a) Remove side trim cover. (See page SF−62).
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminals VTA and E2 of ECM con-
nector.
OK:
Throttle ValveVoltage
Fully closed0.3 − 0.8 V
Fully open3.2 − 4.9 V

A00389
ON
E2
(−)VC
(+)
− DIAGNOSTICSENGINE
DI−37
1996 RAV4 (RM447U)
NG Check for open and short in harness and con-
nector between ECM and throttle position sen-
sor (VTA or E2 line) (See page IN−30).
OK
Check and replace ECM
(See page IN−30).
5 Check voltage between terminals VC and E2 of ECM connector.
PREPARATION:
(a) Remove side trim cover (See page SF−61).
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminals VC and E2 of ECM con-
nector.
OK:
Voltage 4.5 − 5.5 V
NG Check and replace ECM (See page IN−30).
OK
Check for open in harness and connector
between ECM and sensor (VC line)
(See page IN−30).

DI−38
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
DTC P0121 Throttle/Pedal Position Sensor/Switch ”A”
Circuit Range/Performance Problem
CIRCUIT DESCRIPTION
Refer to Throttle / Pedal Position Sensor / Switch ”A” Circuit Malfunction on page DI−34.
DTC No.DTC Detecting ConditionTrouble Area
P0121
After the vehicle speed has been exceeded 30 km/h (19 mph)
even once, the output value of the throttle position sensor is
out of the applicable range while the vehicle speed between 30
km/h (19 mph) and 0 km/h (0 mph)
(2 trip detection logic)
Throttle position sensor
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P0121) being output?
YES Go to relevant DTC chart.
NO
Replace throttle position sensor.
DI3ZI−01

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

S02514
1
Oxygen Sensor
(Bank1 Sensor 2)
21
2B
B6
5
14ECM
E5
E5
E4 BR A
A
AA
ECJ2 Junction
Connector Oxygen Sensor
(Bank 1 Sensor 1)
BROX1
OX2
E1
BR
BR
DI−40
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Connect the OBDII scan tool or TOYOTA hand−held tester and read value for
voltage output of oxygen sensor.
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 voltage output of oxygen sensor (bank 1 sensor 1) when engine is suddenly raced.
HINT:
Perform quick racing to 4,000 rpm 3 times using accelerator pedal.
OK:
Oxygen sensor output a RICH signal (0.45 V or more) at least once.
OK Check and replace ECM (See page IN−30).
NG