2003 LEXUS LS430 air condition

Fig. 63: Checking Harness And Connector (Air Conditioning Amplifier - Air Duct Sensor)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT )
CIRCUIT DESCRIPTION
This sensor detects the exhaust gas (HC, CO) outside the vehicle and sends a signal to the A/C amplifier.
Fig. 64: DTC Detection Item Trouble Area Chart

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

Fig. 65: Emission Gas 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:
ItemMeasure Item/Display (Range)Normal ConditionDiagnostic
Note
EMISS GAS
SENSEmission gas / min.: 0 V max.:
255 VIncreases as the gas amount
increases-

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 (DGS - SG-1)
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 (DGS - SG-1) VOLTAGE
HINT:
As the temperature increases, the volta
ge decreases.
NGA
OK (Checking from the PROBLEM SYMPTOM TABLE)B
OK (Checking from the DTC)C
Tester connectionConditionSpecified condition
A11-29 (DGS) - A13-8 (SG-1)Ignition switch ON at 10 to 35°C (50 to 95°F)1.0 to 4.5 V

Fig. 66: Inspecting Air Conditioning Amplifier (DGS - SG-1)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Result:
AIR CONDITIONING AMPLIFIER (DGS - SG-1) 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 EXHAUST GAS SENSOR
a. Remove the exhaust gas sensor.
b. After keeping to apply battery voltage between terminals 3 and 6 for more than 30 seconds,
NGA
OK (Checking from the PROBLEM SYMPTOM TABLE)B
OK (Checking from the DTC)C

OK: Go to next step
4.CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - EXHAUST GAS
SENSOR) (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Measure the resistance according to the value (s) in the table below.
Standard:
AIR CONDITIONING AMPLIFIER - EXHAUST GAS SENSOR RESISTANCE
Tester connectionConditionSpecified condition
E10-1 (S.G) - A13-8 (SG-1)AlwaysBelow 1 ohms
E10-2 (HC) - A11-29 (DGS)AlwaysBelow 1 ohms
E10-1 (S.G) - Body groundAlways10 kohms or higher
A10-2 (HC) - Body groundAlways10 kohms or higher

Fig. 68: Checking Harness And Connector (Air Conditioning Amplifier - Exhaust Gas Sensor)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

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

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