LEXUS LS430 2003 Factory Repair Manual

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT )
CIRCUIT DESCRIPTION
In this circuit, the compressor assembly receives a signal on refrigerant compression required by the air
conditioning amplifier. Based on the signal, the compressor assembly changes the degree of refrigerant
compression.
Fig. 116: DTC Detection Item Trouble Area Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
WIRING DIAGRAM
Fig. 117: Compressor Solenoid Circuit

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INSPECTION PROCEDURE
1.INSPECT AIR CONDITIONING AMPLIFIER (SOL+ - SOL-)
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 (SOL+ - SOL-) VOLTAGE
HINT:
As the temperature increases, the voltage decreases.
Result:
AIR CONDITIONING AMPLIFIER (SOL+ - SOL-) TEST RESULT
Tester connectionConditionSpecified condition
A11-6 (SOL+) - A11-7 (SOL-)Start the engine Auto switch: ONBelow 1.0 V
ANG
BOK (Checking from the PROBLEM SYMPTOMS TABLE)
COK (Checking from the DTC)

Fig. 118: Inspecting Air Conditioning Amplifier (SOL+ - SOL-)
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
2.INSPECT COOLER COMPRESSOR ASSY (AIR CONDITIONER SOLENOID)
a. Disconnect the cooler compressor assy connector.
b. Measure the resistance according to the value (s) in the table below.
Standard:
COOLER COMPRESSOR ASSY (AIR CONDITIONER SOLENOID) RESISTANCE
Tester connectionConditionSpecified condition
1 - 2at 20°C (68°F)10 to 11 ohms

Fig. 119: Inspecting Cooler Compressor Assy (Air Conditioner Solenoid)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE COOLER COMPRESSOR ASSY
OK: Go to next step
3.CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - COOLER
COMPRESSOR ASSY) (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Measure the resistance according to the value (s) in the table below.
Standard:
AIR CONDITIONING AMPLIFIER - COOLER COMPRESSOR ASSY RESISTANCE
Tester connectionConditionSpecified condition
A11-6 (SOL+) - C23-2AlwaysBelow 1 ohms
A11-7 (SOL-) - C23-1AlwaysBelow 1 ohms
A11-6 (SOL+) - Body groundAlways10 kohms or higher
A11-6 (SOL-) - Body groundAlways10 kohms or higher

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