2000 TOYOTA CAMRY coolant temperature

ELECTRIC COOLING FAN REMOVAL
(See Components for Removal and Installation)
1. DISCONNECT NEGATIVE (±) TERMINAL CABLE
FROM BATTERY
CAUTION: Work must be started after 90 seconds from
the time the ignition switch is turned to the 'LOCK'
position and the negative (±) terminal cable is discon±
nected from the battery.
5. REMOVE ELECTRIC COOLING FAN
(a) Disconnect the engine coolant temperature switch
connector from the radiator.
(b) Disconnect the engine coolant temperature switch
and electric cooling fan connectors from the fan
shroud.
(c) Remove the 4 bolts and cooling fan. 2. DRAIN ENGINE COOLANT (See page EG1±241)
3. w/ CRUISE CONTROL SYSTEM:
REMOVE CRUISE CONTROL ACTUATOR COVER
4. DISCONNECT UPPER RADIATOR HOSE FROM
RADIATOR
COMPONENTS FOR DISASSEMBLY AND
ASSEMBLY
± 5S±FE ENGINECOOLING SYSTEMEG1±265

ELECTRIC COOLING FAN INSTALLATION
(See Components for Removal and Installation)
1. INSTALL ELECTRIC COOLING FAN
(a) Install the cooling fan with the 4 bolts.
(b) Connect the engine coolant temperature switch and
electric cooling fan connectors to the fan shroud.
(c) Connect the engine coolant temperature switch connector
to the radiator.
2. CONNECT UPPER RADIATOR HOSE TO RADIATOR
3. w/ CRUISE CONTROL SYSTEM:
INSTALL CRUISE CONTROL ACTUATOR COVER
4. FILL WITH ENGINE COOLANT
(See page EG1±241)
5. CONNECT NEGATIVE (±) TERMINAL CABLE TO
BATTERY
6. START ENGINE AND CHECK FOR LEAKS
ELECTRIC COOLING FAN DISASSEMBLY
(See Components for Disassembly and Assembly)
1. REMOVE FAN
Remove the nut and fan.
ELECTRIC COOLING FAN ASSEMBLY
(See Components for Disassembly and Assembly)
1. INSTALL FAN MOTOR
2. INSTALL FAN 2. REMOVE FAN MOTOR
Remove the screws and fan motor.
± 5S±FE ENGINECOOLING SYSTEMEG1±266

CIRCUIT DESCRIPTION
The engine coolant temperature sensor senses the
engine coolant temperature. A thermistor built in the
sensor changes its resistance value according to the
engine coolant temperature. The lower the engine
coolant temperature, the greater the thermistor resis±
tance value, and the higher the engine coolant tem±
perature, the lower the thermistor resistance value
(See Fig. 1.).
The engine coolant temperature sensor is connected
to the ECM (See next page). The 5 V power source
voltage in the ECM is applied to the engine coolant
temperature sensor from the terminal THW via a resis-
tor R. That is, resistor R and the engine coolant tem±
perature sensor are connected in series. When the
resistance value of the engine coolant temperature
sensor changes in accordance with changes in the
engine coolant temperature, the potential at the ter±
minal THW also changes. Based on this signal, the
ECM increases the fuel injection volume to improve
driveability during cold engine operation. If the ECM
detects the diagnostic trouble code 22, it operates the
fail safe function in which the engine coolant temper±
ature is assumed to be 80
C (176
F).
w
Open or short in engine coolant temp,
sensor circuit
wEngine coolant temp. sensor
wECM Open or short in engine coolant temp. sensor
circuit for 0.5 sec. or more.Diagnostic Trouble Code Detecting Condition
Engine coolant
Temp.
C (
F)Resistance
(k
)
( Reference )
Voltage
(V)
Trouble Area 100 (212)
DTC 22 Engine coolant Temp. Sensor Circuit
60 (140) 40 (104)
80 (176) ±20 (±4)
DTC No.20 (68)0 (32)16.0
0.9
0.3 0.6
0.20.3 0.54.3
2.53.4
5.9
2.4
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±356

DIAGNOSTIC CHART
HINT If diagnostic trouble codes ª22º (engine coolant temperature sensor circuit), ª24º (intake air temperature sensor cir-
cuit), ª31º (manifold absolute pressure sensor circuit) and ª41º (throttle position sensor circuit) are output simultaneously, E2
(sensor ground) may be open, OK Check for momentary interruption
Check for open and short in harness and connector
between ECM and engine coolant temp. sensor.Check for momentary interruption
(See page EG1±309).
Repair or replace harness or
connector.Replace engine coolant temp. sensor.
WIRING DIAGRAM
Check resistance of sensor.
Check and replace ECM.Check voltage of sensor.
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±357

INSPECTION PROCEDURE
HINT: If diagnostic trouble codes ª22º (engine coolant temperature sensor circuit), ª24º (intake air
temperature sensor circuit), ª31º (manifold absolute pressure sensor circuit) and ª41 ª (throttle
position sensor circuit) are output simultaneously, E2 (sensor ground) may be open,
(1) Remove glove compartment
(See page EG1±234)
(2) Turn ignition switch on.
Measure voltage between terminals THW and E2 of engine
control module connector.
Check voltage between terminals THW and E2 of engine control
module connector.
Check for momentary interruption
(See page EG1±309)
Engine Coolant Temp.
C (
F)
20 (68)
( Engine is cool )
80 (176)
(Engine is hot)0.2 ~1.0 v 0.5 ~ 3.4 V Voltage
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±358

DIAGNOSTIC CHART
HINT: If diagnostic trouble codes ª22º (engine coolant temperature sensor circuit), ª24º (intake air
temperature sensor circuit), ª31º (manifold absolute pressure sensor circuit) and ª41º (throt±
tle position sensor circuit) are output simultaneously, E2 (sensor ground) may be open.
CIRCUIT DESCRIPTION
The intake air temp. sensor is built into the air cleaner cap and senses the intake air tempera-
ture. The structure of the sensor and connection to the ECM is the same as in the engine coolant
temp. sensor shown on page EG1±356.
If the ECM detects the diagnostic trouble code ª24º, it operates the fail safe function in which the
intake air temperature is assumed to be 20

C (68
F)
w
Open or short in intake air temp. sensor circuit.
wIntake air temp. sensor
wECM
Check for open and short in harness and
connector between ECM and intake air temp.
sensor.Open or short in intake air temp. sensor circuit
for 0.5 sec. or more.
Check for momentary
interruption (See page EG1±309). Diagnostic Trouble Code Detecting Condition
Repair or replace harness or
connector.Replace intake air temp. sensor.
WIRING DIAGRAM
Check resistance of sensor.
Check and replace ECM. Check voltage of sensor.Trouble Area
DTC 24 Intake Air Temp. Sensor Circuit
DTC No.
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±360

DIAGNOSTIC CHART
HINT: If diagnostic trouble codes ª22º (engine coolant temperature sensor circuit), ª24º (intake air
temperature sensor circuit),ª31º (manifold absolute pressure sensor circuit) and ª41º (throttle posi±
tion sensor circuit) are output simultaneously, E2 (sensor ground) may be open.
Check for open and short in harness and
connector between throttle position sensor and
ECM.Check for momentary interruption
(See page EG1±309).
Adjust or replace throttle position
sensor.
Repair or replace harness or
connector. Check operation for throttle position sensor.Check voltage of throttle position sensor.
WIRING DIAGRAM
Check and replace ECM.
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±377

INSPECTION PROCEDURE
HINT: If diagnostic trouble code ª22º (engine coolant temperature sensor circuit), ª24º (intake air
temperature sensor circuit), ª31º (manifold absolute pressure sensor circuit) and ª41 ª (throttle
position sensor circuit) are output simultaneously, E2 (sensor ground) may be open.
(1) Remove glove compartment.
(See page EG1±234).
(2) Disconnect the vacuum hose from the throt±
tle body, then apply vacuum to the throttle
opener (See page EG1±204).
(3) Turn ignition switch ON.
Measure voltage between terminals VTA, IDL and
E2 of engine control module connector when the
throttle valve is opened gradually from the closed
condition.
Check voltage between terminals VTA, IDL and E2 of engine
control module connector.
The voltage should increase steadily in propor±
tion to the throttle valve opening angle.
Check for momentary interruption
(See page EG1±309).
Throttle Valve
Fully Closed
Fully OpenVTA ± E2 Terminal
IDL ± E2
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±378