LEXUS LS430 2003 Factory Repair Manual

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT )
CIRCUIT DESCRIPTION
A photodiode in the A/C solar sensor detects solar radiation and sends signals to the A/C amplifier.
Fig. 69: Photodiode Resistance/Solar Radiation Strength Graph

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Fig. 70: DTC Detection Item Trouble Area Chart
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HINT:
If DTC B1244 is output at the same time, troubleshoot DTC B1244: LIGHT SENSOR CIRCUIT
MALFUNCTION .
WIRING DIAGRAM
Fig. 71: Solar Sensor Circuit (Passenger Side)

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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 (TSPa)
a. Remove the A/C amplifier with connector 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 (TSPA) VOLTAGE
HINT:
As the inspection light is moved away from the sensor, the voltage increases.
Use an incandescent lamp for inspection. Bring it within 30 cm (11.8 in.) of the A/C solar sensor.
ItemMeasure Item/Display (Range)Normal ConditionDiagnostic
Note
SOLAR
SENS-PSolar sensor (Passenger side) / min.: 0
max.: 255decreases as brightness
increases-
NGA
OK (Checking from the PROBLEM SYMPTOM TABLE)B
OK (Checking from the DTC)C
Tester connectionConditionSpecified condition
A11-20 (TSPa) - Body groundSensor is subjected to electric light4.0 to 4.6 V
A11-20 (TSPa) - Body groundSensor is covered by a clothBelow 0.8 V

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Result:
AIR CONDITIONING AMPLIFIER (TSPA) 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
3.INSPECT A/C SOLAR SENSOR
a. Remove the A/C solar sensor.
b. Apply battery voltage between terminals A28-6 (CLTB) and A28-3 (CLTE) of the A/C solar
sensor.
NGA
OK (Checking from the PROBLEM SYMPTOMS TABLE)B
OK (Checking from the DTC)C

c. Measure the voltage according to the value (s) in the table below.
Standard:
A/C SOLAR SENSOR VOLTAGE
HINT:
As the inspection light is moved away from the sensor, the voltage increases.
Use an incandescent lamp for inspection. Bring it within 30 cm (11.8 in.) of the solar sensor.
Tester connectionConditionSpecified condition
A28-2 (TSR) - A28-3 (CLTE)Sensor is subjected to electric light4.0 to 4.6 V
A28-2 (TSR) - A28-3 (CLTE)Sensor is covered by a clothBelow 0.8 V

Fig. 73: Inspecting A/C Solar Sensor
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NG: REPLACE A/C SOLAR SENSOR
OK: Go to next step
4.CHECK HARNESS AND CONNECTOR (A/C SOLAR SENSOR - AIR CONDITONING
AMPLIFIER) (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Measure the resistance according to the value (s) in the table below.
Standard:
A/C SOLAR SENSOR - AIR CONDITONING AMPLIFIER RESISTANCE
Tester connectionConditionSpecified condition
A11-20 (TSPa) - A28-2 (TSR)AlwaysBelow 1 ohms
A11-20 (TSPa) - Body groundAlways10 kohms or higher

Fig. 74: Checking Harness And Connector (A/C Solar Sensor - Air Conditoning Amplifier)

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NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
The pressure switch sends the appropriate signals to the A/C amplifier when the A/C refrigerant pressure drops
too low or rises too high.
When the A/C amplifier receives these signals, the compressor does not compress refrigerant.
Fig. 75: DTC Detection Item Trouble Area Chart

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WIRING DIAGRAM

Fig. 76: Pressure Switch Circuit
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INSPECTION PROCEDURE
1.CHECK REFRIGERANT VOLUME
a. Check the sight glass on the liquid tube.
Test conditions:
Engine is running at 1,500 rpm
Single A/C:
Blower speed control switch at "HI" position
Dual A/C:
Front blower switch at "HI" position
Rear blower switch at "HI" position

A/C switch ON
Single A/C:
Temperature control switch at "MAX. COOL" position
Dual A/C:
Rear temperature control switch at "MAX. COOL" position
Front driver side temperature control switch at "MAX. COOL" position
Front passenger side temperature control switch at "MAX. COOL" position
Fully open the doors
Fig. 77: Checking Refrigerant Volume

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