evap LEXUS LS430 2003 Factory Repair Manual

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

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 %
-

AIR MIX STEP-
DAir mix servomotor target STEP
(Driver side) / min.: 257 STEP
max.: 1571 STEPMAX COOL: Approx. 257 STEP
MAX HOT: Approx. 1,571 STEP-
AIR MIX STEP-
PAir mix servomotor target STEP
(Passenger side) / min.: 257 STEP
max.: 1571 STEPMAX COOL: Approx. 257 STEP
MAX HOT: Approx. 1,571 STEP-
AIR OUT STEP-
DAir outlet servomotor target STEP
(Driver side) / min.: 274 STEP
max.: 2060 STEPFACE: Approx. 274 STEP DEF:
Approx. 2,060 STEP-
AIR OUT STEP-
PAir outlet servomotor target STEP
(Passenger side) / min.: 274 STEP
max.: 2060 STEPFACE: Approx. 274 STEP DEF:
Approx. 2,060 STEP-
HAND FREE
TELHand free telephone / OFF, ON--
BLOWER
LEVELBlower motor speed level / min.:
0 level max.: 31 levelIncreases in the range between 0 and
31 as the speed increase-
AMBI TEMP
Adjusted ambient temperature /
min.: -30.8°C (-23.44°F) max.:
50.8°C (123.44°F)
--
LOW VOLT
COUNT+B abnormal low voltage / min.: 0
times max.: 255 times--
EMISS GAS
SENSEmission gas / min.: 0 V max.:
255 VIncreases as the gas amount increases-
SET TEMP
SHIFTShift set temperature / +2C, +1C,
NORMAL, -1C, -2CCustomized value will be displayed-
AIR INLET
MODEAir inlet mode / AUTO,
MANUALCustomized value will be displayed-
COMPRESSOR
MODECompressor mode / AUTO,
MANUALCustomized value will be displayed-
COMPRS/DEF
OPERCompressor/ DEF operation
mode /LINK, NORMALCustomized value will be displayed-
MOTOR
INITIALIZEMotor initialize after IG SW being
turned OFFCustomized value will be displayed-
EVAP CTRLEvaporator control /AUTO,
MANUALCustomized value will be displayed-
GAS SENS
SHIFT
Emission Gas Sensor Shift / MU
MORE, MORE, LI MORE,
NORMAL, LI LESS, LESS, MU
LESS
Customized value will be displayed-
AUTO MODESwing resister auto mode /
AUTO, MANUALCustomized value will be displayed-
BUTTON PRS
BUZButton press buzzer / ON, OFFCustomized value will be displayed-
FILTER SENSFilter sensor / LESS, NORMAL,
MORECustomized value will be displayed-

AOPa2 - GND
(A36-6 - A11-1)P-B - W-
BAir outlet servomotor
operation signal
(Passenger side)During actuator check mode.
Change display code 0 to display
code 9.Pulse
generation
AOPa3 - GND
(A36-7 - A11-1)P-G - W-
BAir outlet servomotor
operation signal
(Passenger side)During actuator check mode.
Change display code 0 to display
code 9.Pulse
generation
AOPa4 - GND
(A36-9 - A11-1)P-L - W-
BAir outlet servomotor
operation signal
(Passenger side)During actuator check mode.
Change display code 0 to display
code 9.Pulse
generation
S5-5 - SG-7(1)
(A36-11 - A36-
15)
R - W-L
Cool air bypass damper
position sensor signal
(Driver side)
Ignition switch ON.4.5 to 5.5 V
S5-5 - SG-7(2)
(A36-11 - A36-
15)
R - W-L
Cool air bypass damper
position sensor signal
(Passenger side)
Ignition switch ON.4.5 to 5.5 V
AMPB - GND
(A36-13 - A11-1)Y - W-B
Air mix servomotor
operation voltage
(Passenger side)
Always10 to 14 V
AIF - SG (A36-
16 - A37-19)G-R - W-
BAir inlet damper position
sensor signalIgnition switch ON. Push REC
switch.Below 1.0 V
AIF - SG (A36-
16 - A37-19)G-R - W-
BAir inlet damper position
sensor signalIgnition switch ON. Push FRESH
switch.10 to 14 V
AIR - SG (A36-
17 - A37-19)G-Y - W-
BAir inlet damper position
sensor signalIgnition switch ON. Push FRESH
switch.Below 1.0 V
AIR - SG (A36-
17 - A37-19)G-Y - W-
BAir inlet damper position
sensor signalIgnition switch ON. Push REC
switch.10 to 14 V
TE - SG-7 (A36-
20 - A36-15)L-Y - W-
LEvaporator temperature
sensor signalIgnition switch ON. Evaporator
temperature 0 °C (32 °F).2.0 to 2.4V
TE - SG-7 (A36-
20 - A36-15)L-Y - W-
LEvaporator temperature
sensor signalIgnition switch ON. Evaporator
temperature 15 °C (59 °F).1.4 to 1.8 V
TPBDr - SG-7
(A36-24 - A36-
15)B-R - W-
LCool air bypass
servomotor operation
signal (Driver side)Change display code 9 to display
code 0.3.5 to 4.5 V
TPBDr - SG-7
(A36-24 - A36-
15)B-R - W-
LCool air bypass
servomotor operation
signal (Driver side)Change display code 2 to display
code 3.0.5 to 1.8 V
AOPB - GND
(A36-26 - A11-1)Y-R - W-
BAir outlet servomotor
operation voltage
(Passenger side)
Always10 to 14 V
(1)w/o LEXUS Navigation System
(2)w/ Rear A/C

1.STEP MOTORS INITIALIZING FUNCTION
STEP motor initializing procedure (Automatic initializing)
1. When the battery is reconnected and the ignition switch is turned to the ON position for the first
time, the initializing function of the STEP motors is activated. In this case, the "FRONT DEF"
indicator blinks.
SET TEMP SHIFT
(Set Temperature
Shift)
NORMALTo control with the shifted temperature
against the display temperature.+2C/+1C/ NORMAL -
1C / -2C
AIR INLET MODE
(Air Inlet Mode)AUTO
In case of turning the A/C ON when you
desire to make the compartment cool down
quickly, this is the function to change the
mode automatically to RECIRCULATED
mode.
MANUAL / AUTO
COMPRESSOR
MODE (Compressor
Mode)
AUTO
Function to turn the A/C ON automatically
by pressing the AUTO button when the
blower is ON and the A/C is OFF.
MANUAL / AUTO
COMPRS/DEF OPER
(Compressor/Air Inlet
DEF Operation)
LINK
Function to turn the A/C ON automatically
linking with the FRONT DEF button when
A/C is OFF.
NORMAL / LINK
MOTOR INITIALIZ
(STEP Motor
Initializing (IG/off))
OFFFunction to initialize the STEP motor after
the ignition switch is OFF.ON / OFF
EVAP CTRL
(External Variable
Control OFF)
AUTO
Function to set the evaporator control to the
AUTOMATIC position (AUTO) to save
power or to the coldest position
(MANUAL) to dehumidify the air and to
prevent the windows from fogging up.
MANUAL / AUTO
GAS SENS SHIFT
(Shift Emission Gas
Sensor Sensitivity)
NORMALFunction to change the sensitivity of the
exhaust gas sensor.
MU MORE /MORE / LI
MORE / NORMAL / LI
LESS / LESS / MU
LESS
AUTO MODE
(Cancel Auto Mode)AUTOFunction to swing the vent vans
automatically when A/C is ON.MANUAL / AUTO
BUTTON PRS BUS
(Cancel Operating
Switch Sound)
ONFunction to sound a buzzer when a button
is pressed.OFF / ON
FILTER SENS (Shift
Filter Clog Sensitivity)NORMALFunction to change the sensitivity of the air
conditioning filter choking sensor.LESS / NORMAL /
MORE
FOOT AIR LEAK
(Cancel Air Outlet
Foot II)
ONFunction to cut off the airstream felt
underfoot while the vehicle is moving.OFF / ON

Fig. 31: Rear A/C Problem Symptoms Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Air Purifier
Fig. 32: Air Purifier Problem Symptoms Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Intelligent Swing Register
Fig. 33: Intelligent Swing Register Problem Symptoms Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
If a malfunction code is displayed during the DTC check (sensor check), check the circuit listed for that code in
the table below.
DIAGNOSTIC TROUBLE CODE CHART
DTCDescription
DTC B1411ROOM TEMPERATURE SENSOR CIRCUIT
DTC B1412AMBIENT TEMPERATURE SENSOR CIRCUIT
DTC B1413EVAPORATOR TEMPERATURE SENSOR CIRCUIT
DTC B1415AIR DUCT SENSOR CIRCUIT (DRIVER SIDE)
DTC B1416AIR DUCT SENSOR CIRCUIT (PASSENGER SIDE)
DTC B1418EMISSION GAS SENSOR CIRCUIT
DTC B1421SOLAR SENSOR CIRCUIT (PASSENGER SIDE)
DTC B1423PRESSURE SWITCH CIRCUIT
DTC B1424SOLAR SENSOR CIRCUIT (DRIVER SIDE)
DTC B1428REAR SOLAR SENSOR CIRCUIT
DTC B1432AIR INLET DAMPER POSITION SENSOR CIRCUIT
DTC B1434MAX COOL DAMPER POSITION SENSOR CIRCUIT (DRIVER SIDE)
DTC B1435MAX COOL DAMPER POSITION SENSOR CIRCUIT (PASSENGER SIDE)

OK: REPLACE ECM (SEE REPLACEMENT)
CIRCUIT DESCRIPTION
This sensor detects the evaporator temperature and sends the appropriate signals to the A/C amplifier. It is used
for frost prevention, temperature and time-lag air flow control.
Fig. 47: DTC Detection Item Trouble Area Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
WIRING DIAGRAM
Fig. 48: Evaporator Temperature 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:
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 (TE - SG)
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 (TE - SG) VOLTAGE
HINT:
ItemMeasure Item/Display (Range)Normal ConditionDiagnostic
Note
EVAP
TEMPEvaporator temperature sensor / min.: -29.7°C (-
21.46°F) max.: 59.55°C (139.19°F)Actual evaporator
temperature is displayed-
NGA
OK (Checking from the PROBLEM SYMPTOM TABLE)B
OK (Checking from the DTC)C
Tester connectionConditionSpecified condition
A36-20 (TE) - A36-15 (SG-7)Ignition switch ON at 0°C (32°F)2.0 to 2.4 V
A36-20 (TE) - A36-15 (SG-7)Ignition switch ON at 15°C (59°F)1.4 to 1.8 V

As the temperature increases, the voltage decreases.
Result:
AIR CONDITIONING AMPLIFIER (TE - SG) TEST RESULT
B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
C: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT )
Fig. 49: Inspecting Air Conditioning Amplifier (TE
- SG)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
A: Go to next step
3.INSPECT A/C EVAPORATOR TEMPERATURE SENSOR
a. Remove the A/C evaporator temperature sensor.
b. Measure the resistance according to the value (s) in table below.
NGA
OK (Checking from the PROBLEM SYMPTOM TABLE)B
OK (Checking from the DTC)C

Standard:
A/C EVAPORATOR TEMPERATURE SENSOR RESISTANCE
<0029004c004a0011000300180013001d0003002c005100560053004800460057004c0051004a000300240012002600030028005900440053005200550044005700520055000300370048005000530048005500440057005800550048000300360048005100
5600520055[

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Tester connectionConditionSpecified condition
1 - 2-10°C (14°F)7.40 to 9.20 kohms
1 - 2-5°C (23°F)5.65 to 7.00 kohms
1 - 20°C (32°F)4.35 to 5.40 kohms
1 - 25°C (41°F)3.40 to 4.20 kohms
1 - 210°C (50°F)2.68 to 3.30 kohms
1 - 215°C (59°F)2.10 to 2.60 kohms
1 - 220°C (68°F)1.66 to 2.10 kohms
1 - 225°C (77°F)1.32 to 1.66 kohms
1 - 230°C (86°F)1.05 to 1.35 kohms