2003 LEXUS LS430 sensor

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NG: REPLACE A/C AMBIENT TEMPERATURE SENSOR
OK: Go to next step
4.CHECK HARNESS AND CONNECTOR (ECM-A/C AMBIENT TEMPERATURE SENSOR)
(SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Measure the resistance according to the value (s) in the table below.
Standard:
ECM-A/C AMBIENT TEMPERATURE SENSOR RESISTANCE
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
Tester connectionConditionSpecified condition
E3-18 (TAM) - A1-1AlwaysBelow 1 ohms
E5-28 (E2) - A1-2AlwaysBelow 1 ohms
E3-18 (TAM) - Body groundAlways10 kohms or higher
E5-28 (E2) - Body groundAlways10 kohms or higher

Fig. 46: Checking Harness And Connector (ECM-A/C Ambient Temperature Sensor)
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OK: REPLACE ECM (SEE REPLACEMENT)
CIRCUIT DESCRIPTION
This sensor detects the evaporator temperature and sends the appropriate signals to the A/C amplifier. It is used
for frost prevention, temperature and time-lag air flow control.
Fig. 47: DTC Detection Item Trouble Area Chart

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WIRING DIAGRAM
Fig. 48: Evaporator Temperature Sensor Circuit

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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:
AIR CONDITIONER TEST RESULT
B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
C: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT )
A: Go to next step
2.INSPECT AIR CONDITIONING AMPLIFIER (TE - SG)
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 (TE - SG) VOLTAGE
HINT:
ItemMeasure Item/Display (Range)Normal ConditionDiagnostic
Note
EVAP
TEMPEvaporator temperature sensor / min.: -29.7°C (-
21.46°F) max.: 59.55°C (139.19°F)Actual evaporator
temperature is displayed-
NGA
OK (Checking from the PROBLEM SYMPTOM TABLE)B
OK (Checking from the DTC)C
Tester connectionConditionSpecified condition
A36-20 (TE) - A36-15 (SG-7)Ignition switch ON at 0°C (32°F)2.0 to 2.4 V
A36-20 (TE) - A36-15 (SG-7)Ignition switch ON at 15°C (59°F)1.4 to 1.8 V

As the temperature increases, the voltage decreases.
Result:
AIR CONDITIONING AMPLIFIER (TE - SG) TEST RESULT
B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
C: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT )
Fig. 49: Inspecting Air Conditioning Amplifier (TE
- SG)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
A: Go to next step
3.INSPECT A/C EVAPORATOR TEMPERATURE SENSOR
a. Remove the A/C evaporator temperature sensor.
b. Measure the resistance according to the value (s) in table below.
NGA
OK (Checking from the PROBLEM SYMPTOM TABLE)B
OK (Checking from the DTC)C

Standard:
A/C EVAPORATOR TEMPERATURE SENSOR RESISTANCE
<0029004c004a0011000300180013001d0003002c005100560053004800460057004c0051004a000300240012002600030028005900440053005200550044005700520055000300370048005000530048005500440057005800550048000300360048005100
5600520055[

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Tester connectionConditionSpecified condition
1 - 2-10°C (14°F)7.40 to 9.20 kohms
1 - 2-5°C (23°F)5.65 to 7.00 kohms
1 - 20°C (32°F)4.35 to 5.40 kohms
1 - 25°C (41°F)3.40 to 4.20 kohms
1 - 210°C (50°F)2.68 to 3.30 kohms
1 - 215°C (59°F)2.10 to 2.60 kohms
1 - 220°C (68°F)1.66 to 2.10 kohms
1 - 225°C (77°F)1.32 to 1.66 kohms
1 - 230°C (86°F)1.05 to 1.35 kohms

HINT:
As the temperature increases, the resistance decrease (see the graph below).
Fig. 51: Resistance/Temperature Graph

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NG: REPLACE A/C EVAPORATOR TEMPERATURE SENSOR
HINT:
When replacing the evaporator temperature sensor, the attached sub-harness should be replaced along
with the sensor.
OK: Go to next step
4.CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - A/C
EVAPORATOR TEMPERATURE SENSOR) (SEE ELECTRONIC CIRCUIT INSPECTION
PROCEDURE )
a. Measure the resistance according to the value (s) in the table below.
Standard:
AIR CONDITIONING AMPLIFIER - A/C EVAPORATOR TEMPERATURE SENSOR

Fig. 53: Identifying Terminals Of A/C Evaporator Temperature Sensor Connector
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NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
This sensor detects the register temperature and sends the appropriate signals to the A/C amplifier.
Fig. 54: DTC Detection Item Trouble Area Chart

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