1996 TOYOTA RAV4 Engine

DI−24
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
DTC P0106 Manifold Absolute Pressure Circuit Range/
Performance Problem
CIRCUIT DESCRIPTION
Refer to Manifold Absolute Pressure / Barometric Pressure Circuit Malfunction on page DI−21.
DTC No.DTC Detecting ConditionTrouble Area
P0106
After the engine is warmed up, conditions (a) and (b) continue
with engine speed 400 ∼ 1,000 rpm
(2 trip detection logic)
(a) Throttle valve fully closed
(b) Manifold absolute pressure sensor output > 3.0 V
Manifold absolute pressure sensor.Condition (c) and (d) continue with engine speed 2,500 rpm or
less
(2 trip detection logic)
(c) VTA > 1.8
(d) Manifold absolute pressure sensor output < 1.0 V
WIRING DIAGRAM
Refer to Manifold Absolute Pressure / Barometric Pressure Circuit Malfunction on page DI−21.
INSPECTION PROCEDURE
HINT:
If DTC ”P0105” (Manifold Absolute Pressure / Barometric Pressure Circuit Malfunction) and ”P0106” (Man-
ifold Absolute Pressure / Barometric Pressure Circuit Range / Performance Problem) are output simulta-
neously, manifold absolute pressure sensor circuit may be open.
Perform troubleshooting of DTC P0105 first.
1 Are there any other codes (besides DTC P0106) being output?
YES Go to relevant DTC chart.
NO
Replace manifold absolute pressure sensor.
DI3ZD−01

FI4741
20 30
10
5
3
2
0.1 0.2 0.3 0.51
−20
(−4) 0
(32) 20
(68) 40
(104) 60
(140) 80
(176)100
(212)
Temperature °C (°F) Acceptable
Resistance (Ω)
(fig. 1)
− DIAGNOSTICSENGINE
DI−25
1996 RAV4 (RM447U)
DTC P0110 Intake Air Temp. Circuit Malfunction
CIRCUIT DESCRIPTION
The intake air temp. sensor is built into the air cleaner cap and
senses the intake air temperature.
A thermistor built in the sensor changes the resistance value
according to the intake air temperature.
The lower the intake air temperature, the greater the thermistor
resistance value, and the higher the intake air temperature, the
lower the thermistor resistance value (See Fig. 1.).
The intake air temperature sensor is connected to the ECM
(See next page). The 5 V power source voltage in the ECM is
applied to the intake air temperature sensor from the terminal
THA via a resistor R.
That is , the resistor R and the intake air temperature sensor are
connected in series. When the resistance value of the intake air
temperature sensor changes in accordance with changes in the
intake air temperature, the potential at terminal THA also
changes. Based on this signal, the ECM increases the fuel in-
jection volume to improve driveability during cold engine opera-
tion.
If the ECM detects the DTC ”P0110”, it operates the fail safe
function in which the intake air temperature is assumed to be
20°C (68°F).
Intake Air Temp.
°C (°F)Resistance
(kΩ)Voltage
(V)
−20 (−4)16.24.3
0 (32)5.93.4
20 (68)2.52.4
40 (104)1.11.4
60 (140)0.60.9
80 (176)0.30.5
100 (212)0.20.3
DTC No.DTC Detecting ConditionTrouble Area
P0110Open or short in intake air temp. sensor circuit
Open or short in intake air temp. sensor circuit
Intake air temp. sensor
ECM
HINT:
After confirming DTC P0110 use the OBDII scan tool or TOYOTA hand−held tester to confirm the intake air
temperature from ”CURRENT DATA”.
Temperature DisplayedMalfunction
− 40°C (− 40°F)Open circuit
140°C (284°F) or moreShort circuit
DI3ZE−01

P19745
Intake Air Temp. Sensor
Y−B
BRE5
E5E2 THAR5V
E1 93ECM
2
1
DI−26
− DIAGNOSTICSENGINE
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 the OBDII scan tool or TOYOTA hand−held tester, and read value of
intake air temperature.
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 temperature value on the OBDII scan tool or TOYOTA hand−held tester.
OK:
Same as actual intake air temperature.
HINT:
If there is open circuit, OBDII scan tool or TOYOTA hand−held tester indicates − 40°C (− 40°F).
If there is short circuit, OBDII scan tool or TOYOTA hand−held tester indicates 140°C (284°F) or more.
NG− 40°C (− 40°F) .... Go to step 2.
140°C (284°F) .... Go to step 4.
OK
Check for intermittent problems.
(See page DI−3).

A00391
Intake Air
Temp. SensorON
2
1E5
E53
95V
E2THA
E1 ECM
A00392
Intake Air
Temp. SensorON
E5
E53
95V
E2THA
E1 ECM
THA
E2
− DIAGNOSTICSENGINE
DI−27
1996 RAV4 (RM447U)
2 Check for open in harness or ECM.
PREPARATION:
(a) Disconnect the intake air temp. sensor connector.
(b) Connect sensor wire harness terminals together.
(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 Confirm good connection at sensor.
If OK, replace intake air temp. sensor.
NG
3 Check for open in harness or ECM.
PREPARATION:
(a) Remove side trim cover (See page SF−61).
(b) Connect between terminals THA and E2 of ECM connec-
tor.
HINT:
Intake air temp. sensor connector is disconnected. Before
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 (294°F) or more
OK Open in harness between terminals E2 or THA,
repair or replace harness.
NG
Confirm good connection at ECM.
If OK, replace ECM.

A00393
Intake Air
Temp. SensorON
2
1
E5E5
3
95V
E2THA
E1 ECM
A00394
Intake Air
Temp. SensorON
5V
E2
THA
E1 ECM
E5
connector
DI−28
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
4 Check for short in harness and ECM.
PREPARATION:
(a) Disconnect the intake air 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 intake air temp. sensor.
NG
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:
Intake air 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).

P19746
Engine Coolant Temp. Sensor
W
BRE5
E5E2THW5V
E1 94ECM
2
1
− DIAGNOSTICSENGINE
DI−29
1996 RAV4 (RM447U)
DTC P0115 Engine Coolant Temp. Circuit Malfunction
CIRCUIT DESCRIPTION
A thermistor built into the engine coolant temperature sensor changes the resistance value according to the
engine coolant temperature.
The structure of the sensor and connection to the ECM is the same as in the intake air temp. circuit malfunc-
tion shown on page DI−25.
If the ECM detects the DTC P0115, it operates the fail safe function in which the engine coolant temp. is
assumed to be 80°C (176°F).
DTC No.DTC Detecting ConditionTrouble Area
P0115Open or short in engine coolant temp. sensor circuit
Open or short in engine coolant temp. sensor circuit
Engine coolant temp. sensor
ECM
HINT:
After confirming DTC P0115 use the OBDII scan tool or TOYOTA hand−held tester to confirm the engine
coolant temperature from ”CURRENT DATA”.
Temperature DisplayedMalfunction
− 40°C (− 40°F)Open circuit
140°C (284°F) or moreShort circuit
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.
DI3ZF−01

A00395
Engine Coolant
Temp. Sensor
E5
E2
THW
5V
94ECM
E5E1
1 2
ON
DI−30
− DIAGNOSTICSENGINE
1996 RAV4 (RM447U)
1 Connect the OBDII scan tool or TOYOTA hand−held tester, and read value of en-
gine coolant temperature.
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 temperature value on the OBDII scan tool or TOYOTA hand−held tester.
OK:
Same as actual engine coolant temperature.
HINT:
If there is open circuit, OBDII scan tool or TOYOTA hand−held tester indicates − 40°C (− 40°F).
If there is short circuit, OBDII scan tool or TOYOTA hand−held tester indicates 140°C (284°F) or more.
NG− 40°C (− 40°F) .... Go to step 2.
140°C (284°F) or more .... Go to step 4.
OK
Check for intermittent problems
(See page DI−3).
2 Check for open in harness or ECM.
PREPARATION:
(a) Disconnect the engine coolant temp. sensor connector.
(b) Connect sensor wire harness terminals together.
(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 Confirm good connection at sensor. If OK,
replace engine coolant temp. sensor.
NG

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