Signal compressor condition LEXUS LS430 2003 Factory Repair Manual

Fig. 6: Air Conditioning System Diagram (2 Of 2)
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1.GENERAL
a. The air conditioning system has the following features:
In compliance with the temperature set at the temperature control switch, the neural network
control calculates the outlet temperature based on the input signals from various sensors. In
addition, corrections in accordance with the signals from the evaporative temperature sensor
and the water temperature sensor are added to control the outlet air temperature.
Controls the front and rear blower motors in accordance with the airflow volume that has
been calculated by the neural network control based on the input signals from various
sensors.
Automatically switches the outlets in accordance with the outlet mode ratio that has been
calculated by the neural network control based on the input signals from various sensors.
Automatically controls the air inlet control damper in accordance with the airflow volume
that has been calculated by the neural network control.
Turns the compressor on/off and controls the discharge capacity based on the signals from
various sensors.
Based on the signals from the ambient temperature sensor, this control calculates the outside
temperature, which is then corrected in the air conditioner ECU, and shown in the multi-
information display in the combination meter.
Switched the rear defogger and outside rear view mirror heaters on for 15 minutes when the
rear defogger switch is switched on. Switched them off if the switch is pressed while they are
operating.
Controls the orientation and the angle of the front center register based on the input signals
from various sensors and on the outlet mode.
Determines whether the clean air filter (for the front A/C) is clogged by monitoring the air
inlets, and airflow volume.
The A/C amplifier automatically controls the air inlets based on the signals from the smog
ventilation sensor.
Improves the air quality by linking the air inlet control damper and the blower motor (for the
rear A/C and air purifier), based on the signals from the exhaust gas sensor and the smoke
sensor.
Checks the sensors in accordance with operation of the air conditioner switches.
2.MODEL POSITION AND DAMPER OPERATION

Fig. 22: Identifying Air Conditioning Amplifier Connector Front View
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AIR CONDITIONING AMPLIFIER CONNECTOR SPECIFICATIONS
ItemTest Details / Display (Range)Diagnostic Note
ACTUATOR CHECKActuator check / OFF, ON-
Symbols
(Terminal No.)Wiring
colorTerminal DescriptionConditionSpecification
GND - Body
ground (A11-1 -
Body ground)W-B -
Body
groundGround for main power
supplyAlwaysBelow 1.0
ohms
MPX+ (A11-2)GR-BMultiplex communication
systemMultiplex communication circuit-
ACC - GND
(A11-3 - A11-1)GR - W-
BPower source (ACC)Turn ignition switch to ACC.10 to 14 V
MPX- (A11-4)GR-BMultiplex communication
systemMultiplex communication circuit-
BLW - GND
(A11-5 - A11-1)LG-B -
W-BBlower motor speed
control voltageBlower fan speed OFF --> M2 -->
HIPulse
generation
SOL+ - SOL-
(A11-6 - A11-7)P - Y-BCompressor operation
signalA/C magnetic clutch to ON.Pulse
generation
RDFGR - GND
(A11-8 - A11-1)W - W-BRear defogger operation
voltageIgnition switch ON. Rear
defogger switch to OFF.10 to 14 V
RDFGR - GND
(A11-8 - A11-1)W - W-BRear defogger operation
voltageIgnition switch ON. Rear
defogger switch to ON.Below 1.0 V
IG - GND (A11-9
- A11-1)LG-R -
W-BPower source (IG)Ignition switch ON.10 to 14 V

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 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

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

10.INSPECT FOR CLOGGED AIR TUBE
a. Check the air tube visually for a clog or damage (see ON
-VEHICLE INSPECTION ).
OK:
Air tube is not clogged or damaged.
NG: REPAIR OR REPLACE AIR TUBE
OK: REPLACE SUSPENSION CONTROL ECU (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
The signal from the suspension control ECU operates the AIR SUS relay and the height control compressor
motor starts.
The height control compressor motor operates until the targeted vehicle height is reached. Then the height
control sensor sub-assy sends the signal to the suspension control ECU, and stops the height control compressor
motor.
Fig. 104: DTC C1751 And DTC C1752 Detecting Condition And Trouble Area

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INSPECTION PROCEDURE
1.CHECK HEIGHT CONTROL COMPRESSOR CIRCUIT (SEE DTC C1742 HEIGHT
CONTROL COMPRESSOR CIRCUIT )
2.CHECK AIR LEAKAGE (SEE ON
-VEHICLE INSPECTION )
OK:
No leaks