2003 LEXUS LS430 air condition

Fig. 4: Identifying Air Conditioning System Component Location (2 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Fig. 5: Air Conditioning System Diagram (1 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Fig. 6: Air Conditioning System Diagram (2 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
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. 7: Identifying Model Position And Damper Operation (Front Air Conditioning)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Fig. 8: Identifying Model Position And Damper Operation (Rear Air Conditioning And Air
Purifier)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
3.AIR OUTLETS AND AIR VOLUME RATIONS

Fig. 21: Display Code - Conditions Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
1.DATA LIST
HINT:
From the DATA LIST displayed on the hand-held tester, you can read the values of the displays, sensors,
actuators and so on without parts removal. Reading the DATA LIST as the first STEP of troubleshooting
is one way to shorten labor time.
a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch to the ON position.
c. From the display on the tester, select the "DATA LIST".
DATA LIST / AIR CONDITIONER:
DATA LIST / AIR CONDITIONER
ItemMeasurement Item / Display
(Range)Normal ConditionDiagnostic
Note

ROOM TEMP
Room temperature sensor / min.: -
6.5°C (20.3°F) max.: 57.25°C
(126.95°F)
Actual room temperature is displayed-
AMBI TEMP
SENSAmbient temperature sensor /
min.: -23.3°C (-9.94°F) max.:
65.95°C (150.71°F)Actual ambient temperature is
displayed-
EVAP TEMP
Evaporator temperature sensor /
min.: -29.7°C (-21.46°F) max.:
59.55°C (139.19°F)Actual evaporator temperature is
displayed-
SOLAR SENS-DSolar sensor (Driver side) / min.:
0 max.: 255Increases as brightness increases-
SOLAR SENS-PSolar sensor (Passenger side) /
min.: 0 max.: 255decreases as brightness increases-
COOLANT
TEMPEngine coolant temperature /
min.: 1.3°C (34.34°F) max.:
90.55°C (194.99°F)Actual engine coolant temperature is
displayed while the engine is warmed
up
-
DUCT TEMP-D
Duct sensor (Driver side) / min.: -
12.7°C (9.14°F) max.: 76.55°C
(169.79°F)Actual duct temperature is displayed
(Driver side)-
DUST TEMP-P
Duct sensor (Passenger side) /
min.: -12.7°C (9.14°F) max.:
76.55°C (169.79°F)Actual duct temperature is displayed
(Passenger side)-
SET TEMP-DSet temperature (Driver side) /
min.: 0 max.: 255Actual set temperature is displayed
(Driver side)-
SET TEMP-PSet temperature (Passenger
side) /min.: 0 max.: 255Actual set temperature is displayed
(Passenger side)-
ESTIMATE
TEMP-DEstimated temperature (Driver
side) / min.: -358.4°C (-613.12°F)
max.: 358.4°C (677.12°F)Actual estimated temperature is
displayed (Driver side)-
ESTIMATE
TEMP-PEstimated temperature (Passenger
side) / min.: -358.4°C (-613.12°F)
max.: 358.4°C (677.12°F)Actual estimated temperature is
displayed (Passenger side)-
A/I DAMP POSAir inlet damper position / min.: -
14% max.: 113.5%RECIRCULATION: Approx. 0%
FRESH: Approx. 100%-
A/B DAMP POS-
DCool air bypass damper position
(Driver side) / min.: -14% max.:
113.5%OPEN: Approx. 0 % SHUT: Approx.
100%-
A/B DAMP POS-
PCool air bypass damper position
(Passenger side) / min.: -14%
max.: 113.5%OPEN: Approx. 0 % SHUT: Approx.
100%-
ItemMeasurement Item / Display
(Range)Normal ConditionDiagnostic
Note
A/I DAMP
TARGAir inlet damper target / min.: -
14% max.: 113.5%RECIRCULATION: Approx. 0%
FRESH: Approx. 100% HALF-
RECIRCULATION: 43 to 99.5 %
-

DATA LIST / ENGINE AND ECT / ALL:
DATA LIST / ENGINE AND ECT / ALL
2.ACTIVE TEST
HINT:
Performing the ACTIVE TEST
using the hand-held tester allows the relays, VSV, actuators and so on to
operate without parts removal. Performing the ACTIVE TEST
as the first STEP of troubleshooting is
one way to shorten labor time.
It is possible to display the DATA LIST on the hand-held tester during the ACTIVE TEST.
a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch to the ON position.
c. From the display on tester, perform the "ACTIVE TEST
".
ACTIVE TEST / AIR CONDITIONER:
ACTIVE TEST / AIR CONDITIONER
FOOT AIR
LEAKFoot air leak / ON, OFFCustomized value will be displayed-
DESTINATION
Destination / DOMEST, USA,
EUROPE, AUSTRAL,
MIDEAST, NO INFO
Changes with destinations-
REAR SOLAR
SENSRear solar sensor / min.: 0 max.:
255Changes depending on brightness-
NOX GAS SENSEmission gas Nox sensor / min.: 0
max.: 255Increases as the gas amount increases-
ItemMeasurement Item / Display
(Range)Normal ConditionDiagnostic
Note
REG PRESS
SENSRegulator pressure sensor / min.:
0 max.: 255Actual regulator pressure is displayed-
FILTER FLOW
VOLFilter flow volume / min.: 0 max.:
65535Actual filter flow volume is displayed-
REG CTRL
CURRNTRegulator control current / min.: 0
A max.: 255 A--
HUMIDITY
SENSHumidity sensor / min.: 0% max.:
100%Actual room humidity is displayed-
#CODESNumber of Trouble Codes / min.:
0 max.: 255Number of DTCs will be displayed-
ItemMeasurement Item/Display (Range)Normal ConditionDiagnostic Note
A/C SIGA/C signal/ ON or OFFA/C ON: ON-