2003 LEXUS LS430 air condition

Fig. 120: Checking Harness And Connector (Air Conditioning Amplifier - Cooler Compressor
Assy)

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 (NOx) outside the vehicle and sends a signal to the A/C amplifier.
Fig. 121: DTC Detection Item Trouble Area Chart

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

Fig. 122: Emission Gas Nox 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
NOX GAS
SENSEmission gas Nox sensor / min.: 0
max.:255Increases 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 (NOX - 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 (NOX - SG-1) VOLTAGE
HINT:
As the temperature increases, the voltage decreases.
Result:
AIR CONDITIONING AMPLIFIER (NOX - SG-1) TEST RESULT
NGA
OK (Checking from the PROBLEM SYMPTOM TABLE)B
OK (Checking from the DTC)C
Tester connectionConditionSpecified condition
A13-17 (NOX) - A13-8 (SG-1)Ignition switch ON at 10 to 35C° (50 to 95°F)1.0 to 4.5 V
NGA
OK (Checking from the PROBLEM SYMPTOMS TABLE)B
OK (Checking from the DTC)C

Fig. 123: Inspecting Air Conditioning Amplifier (NOX - SG-1)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
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 120 seconds,
measure the resistance between terminals 1 and 2.
c. Measure the resistance according to the value (s) in the table below.
Standard:
EXHAUST GAS SENSOR RESISTANCE
Tester connectionConditionSpecified condition
E10-1 (S.G) - E10-4 (NOX)at 10 to 35°C (50 to 95°F)5 to 100 kohms

HINT:
<003a004b0048005100030057004b004800030056004800510056005200550003004c005600030048005b0053005200560048004700030057005200030057004b004800030048005b004b00440058005600570003004a00440056000f00030057004b004800
03005500480056004c0056005700440051004600480003004a[oes down.
Fig. 124: Inspecting Exhaust Gas Sensor

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE EXHAUST GAS SENSOR
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

Fig. 125: 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
The cool air bypass damper control servomotor is controlled by the A/C amplifier and moves the cool air bypass
damper to the desired position.
WIRING DIAGRAM
Fig. 126: Cool Air Bypass Damper Control Servomotor Circuit (Driver Side)

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