Temperature sensor LEXUS LS430 2003 Factory User Guide

1.STEP MOTORS INITIALIZING FUNCTION
STEP motor initializing procedure (Automatic initializing)
1. When the battery is reconnected and the ignition switch is turned to the ON position for the first
time, the initializing function of the STEP motors is activated. In this case, the "FRONT DEF"
indicator blinks.
SET TEMP SHIFT
(Set Temperature
Shift)
NORMALTo control with the shifted temperature
against the display temperature.+2C/+1C/ NORMAL -
1C / -2C
AIR INLET MODE
(Air Inlet Mode)AUTO
In case of turning the A/C ON when you
desire to make the compartment cool down
quickly, this is the function to change the
mode automatically to RECIRCULATED
mode.
MANUAL / AUTO
COMPRESSOR
MODE (Compressor
Mode)
AUTO
Function to turn the A/C ON automatically
by pressing the AUTO button when the
blower is ON and the A/C is OFF.
MANUAL / AUTO
COMPRS/DEF OPER
(Compressor/Air Inlet
DEF Operation)
LINK
Function to turn the A/C ON automatically
linking with the FRONT DEF button when
A/C is OFF.
NORMAL / LINK
MOTOR INITIALIZ
(STEP Motor
Initializing (IG/off))
OFFFunction to initialize the STEP motor after
the ignition switch is OFF.ON / OFF
EVAP CTRL
(External Variable
Control OFF)
AUTO
Function to set the evaporator control to the
AUTOMATIC position (AUTO) to save
power or to the coldest position
(MANUAL) to dehumidify the air and to
prevent the windows from fogging up.
MANUAL / AUTO
GAS SENS SHIFT
(Shift Emission Gas
Sensor Sensitivity)
NORMALFunction to change the sensitivity of the
exhaust gas sensor.
MU MORE /MORE / LI
MORE / NORMAL / LI
LESS / LESS / MU
LESS
AUTO MODE
(Cancel Auto Mode)AUTOFunction to swing the vent vans
automatically when A/C is ON.MANUAL / AUTO
BUTTON PRS BUS
(Cancel Operating
Switch Sound)
ONFunction to sound a buzzer when a button
is pressed.OFF / ON
FILTER SENS (Shift
Filter Clog Sensitivity)NORMALFunction to change the sensitivity of the air
conditioning filter choking sensor.LESS / NORMAL /
MORE
FOOT AIR LEAK
(Cancel Air Outlet
Foot II)
ONFunction to cut off the airstream felt
underfoot while the vehicle is moving.OFF / ON

Fig. 31: Rear A/C Problem Symptoms Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Air Purifier
Fig. 32: Air Purifier Problem Symptoms Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Intelligent Swing Register
Fig. 33: Intelligent Swing Register Problem Symptoms Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
If a malfunction code is displayed during the DTC check (sensor check), check the circuit listed for that code in
the table below.
DIAGNOSTIC TROUBLE CODE CHART
DTCDescription
DTC B1411ROOM TEMPERATURE SENSOR CIRCUIT
DTC B1412AMBIENT TEMPERATURE SENSOR CIRCUIT
DTC B1413EVAPORATOR TEMPERATURE SENSOR CIRCUIT
DTC B1415AIR DUCT SENSOR CIRCUIT (DRIVER SIDE)
DTC B1416AIR DUCT SENSOR CIRCUIT (PASSENGER SIDE)
DTC B1418EMISSION GAS SENSOR CIRCUIT
DTC B1421SOLAR SENSOR CIRCUIT (PASSENGER SIDE)
DTC B1423PRESSURE SWITCH CIRCUIT
DTC B1424SOLAR SENSOR CIRCUIT (DRIVER SIDE)
DTC B1428REAR SOLAR SENSOR CIRCUIT
DTC B1432AIR INLET DAMPER POSITION SENSOR CIRCUIT
DTC B1434MAX COOL DAMPER POSITION SENSOR CIRCUIT (DRIVER SIDE)
DTC B1435MAX COOL DAMPER POSITION SENSOR CIRCUIT (PASSENGER SIDE)

Fig. 34: Diagnostic Trouble Code Information Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
HINT:
*1 If the room temperature is approximately -20°C (-4°F) or lower, DTC B1411/11 may be output even
though the system is normal.
*2 If the ambient temperature is approximately -50°C (-58°F) or lower, a DTC may be output even
though the system is normal.
*3 If the check is being performed in a dark place, DTC B1421/21 (solar sensor circuit abnormal) could
be displayed. In this case, perform DTC check again while shining a light, such as inspection light, on the
solar sensor. If DTC B1421/21 is still displayed, there could be trouble in the solar sensor circuit.
*4 If the check is being performed in a dark place, DTC B1424/24 (solar sensor circuit abnormal) could
be displayed. In this case, perform DTC check again while shining a light, such as inspection light, on the
solar sensor. If DTC B1424/24 is still displayed, there could be trouble in the solar sensor circuit.
*5 If the check is being performed in a dark place, DTC B1421/21 (solar sensor circuit abnormal) could
be displayed. In this case, perform DTC check again while shining a light, such as inspection light, on the
solar sensor. If DTC B1421/21 is still displayed, there could be trouble in the solar sensor circuit.
CIRCUIT DESCRIPTION
This sensor detects the interior temperature that is used as the basis for temperature control and sends
appropriate signals to the A/C amplifier.
Fig. 35: DTC Detection Item Trouble Area Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
WIRING DIAGRAM

Fig. 36: Room Temperature Sensor Circuit
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.READ VALUE ON HAND-HELD TESTER
a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch to the ON position and push the hand-held tester main switch on.
c. Select the item below in the DATA LIST, and read the display on the hand-held tester.
DATA LIST / AIR CONDITIONER:
DATA LIST / AIR CONDITIONER
OK:
The display is as specified in the normal condition.
Result:
ItemMeasure Item/Display (Range)Normal ConditionDiagnostic
Note
ROOM
TEMPRoom temperature sensor / min.: -6.5°C (20.3°F)
max.: 57.25°C (126.95°F)Actual room temperature
is displayed-

AIR CONDITIONER TEST RESULT
B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
C: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT )
A
2.INSPECT COOLER (ROOM TEMPERATURE SENSOR) THERMISTOR
a. Remove the cooler (room temperature sensor) thermistor.
b. Measure the resistance according to the value (s) in the table below.
Standard:
COOLER (ROOM TEMPERATURE SENSOR) THERMISTOR RESISTANCE
NGA
OK (Checking from the PROBLEM SYMPTOM TABLE)B
OK (Checking from the DTC)C
Tester connectionConditionSpecified condition
A14-1 - A14-210°C (50°F)3.00 to 3.73 kohms
A14-1 - A14-215°C (59°F)2.45 to 2.88 kohms
A14-1 - A14-220°C (68°F)1.95 to 2.30 kohms
A14-1 - A14-225°C (77°F)1.60 to 1.80 kohms
A14-1 - A14-230°C (86°F)1.28 to 1.47 kohms
A14-1 - A14-235°C (95°F)1.00 to 1.22 kohms
A14-1 - A14-240°C (104°F)0.80 to 1.00 kohms
A14-1 - A14-245°C (113°F)0.65 to 0.85 kohms
A14-1 - A14-250°C (122°F)0.50 to 0.70 kohms
A14-1 - A14-255°C (131°F)0.44 to 0.60 kohms
A14-1 - A14-260°C (140°F)0.36 to 0.50 kohms

Fig. 37: Identifying Terminals Of A14 A/C Room Temperature Sensor Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
HINT:
As the temperature increases, the resistance decreases (see the
graph below).

Fig. 38: Resistance/Temperature Graph
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE COOLER (ROOM TEMPERATURE SENSOR) THERMISTOR
OK: Go to next step
3.INSPECT AIR CONDITIONING AMPLIFIER (TR - SG-2)
a. Remove the A/C amplifier with connectors still connected.
b. Turn the ignition switch to the ON position.
c. Measure the voltage according to the value (s) in the table below.
Standard:
AIR CONDITIONING AMPLIFIER (TR - SG-2) VOLTAGE
HINT:
As the temperature increases, the voltage decreases.
Result:
AIR CONDITIONING AMPLIFIER TEST RESULT
Tester connectionConditionSpecified condition
A13-16 (TR) - A13-9 (SG-2)Ignition switch ON at 25°C (77°F)1.8 to 2.2 V
A13-16 (TR) - A13-9 (SG-2)Ignition switch ON at 40°C (104°F)1.2 to 1.6 V
NGA

B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
C: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT )
Fig. 39: Inspecting Air Conditioning Amplifier (TR
- SG-2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
A
4.CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - COOLER
(ROOM TEMPERATURE SENSOR)THERMISTOR) (SEE ELECTRONIC CIRCUIT
INSPECTION PROCEDURE )
a. Measure the resistance according to the value (s) in the table below.
Standard:
AIR CONDITIONING AMPLIFIER - COOLER (ROOM TEMPERATURE SENSOR)
THERMISTOR) RESISTANCE
OK (Checking from the PROBLEM SYMPTOMS TABLE)B
OK (Checking from the DTC)C

Temperature Sensor)Thermistor)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
The sensor connected to the ECM detects fluctuations in the ambient temperature that is used for controlling the
interior temperature. The sensor sends a signal to the A/C amplifier via the ECM.
Fig. 41: DTC Detection Item Trouble Area Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
WIRING DIAGRAM

Fig. 42: Ambient Temperature Sensor Circuit
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.READ VALUE ON HAND-HELD TESTER
a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch to the ON position and push the hand-held tester main switch on.
c. Select the item below in the DATA LIST, and read the display on the hand-held tester.
DATA LIST / AIR CONDITIONER:
DATA LIST / AIR CONDITIONER:
OK:
The display is as specified in the normal condition.
ItemMeasurement Item/Display (Range)Normal ConditionDiagnostic
Note
AMBI TEMP
SENSAmbient temperature sensor / min.: -23.3°C (-
9.94°F) max.: 65.95°C (150.71 °F)Actual ambient
temperature is displayed-