coolant temperature LEXUS LS430 2003 Factory Repair Manual

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 %
-

Amplifier)
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 circuit controls the amount of the coolant flowing to the heater core by a signal from the A/C amplifier,
and adjusts the temperature at the air outlets.
WIRING DIAGRAM
Fig. 132: Water Valve Control Servomotor Circuit

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

Fig. 41: SRS Airbag Data List Item Reference Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
STEERING PAD:
Fig. 42: Steering Pad Data List Item Reference Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
ENGINE:
ENGINE DATA LIST ITEM REFERENCE
ABS:
ABS DATA LIST ITEM REFERENCE
ItemMeasurement Item/ Range
(Display)Normal ConditionDiagnostic Note
VEHICLE
SPEEDVehicle speed / Min.: 0 km/h
(0 mph), Max.: 255 km/h (158
mph)Almost same as actual
vehicle speed (When
driving)
-
ENGINE
SPDEngine speed / Min.: 0 rpm,
Max.: 16,383 rpmAlmost same as actual
engine speed (When
engine is running)
-
COOLANT
TEMPCoolant Temperature / Min.: -
40°C (-40°F), Max.: 140 °C
(284 °F)After warning up: 80 to
95°C (178 to 203°F)If the value is "-40°C (-40°F)" or
"140°C (248 °F)", sensor circuit
is open or shorted
ItemMeasurement Item/ Range (Display)Normal ConditionDiagnostic
Note
(FR/FL/RR/RL)
SPDVehicle speed / Min.: 0 km/h (0 mph),
Max.: 326 km/h (202 mph)Almost samo as actual speed
(When driving)-

Fig. 63: Identifying Fuel Sender Gauge Assy And Luggage Room Junction Block Assy Connector
Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE LUGGAGE ROOM JUNCTION BLOCK ASSY
WIRING DIAGRAM
Fig. 64: Water Temperature Receiver Gauge Wiring Diagram

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
HINT:
If there is an open or short in the engine coolant temperature sensor circuit, the ECM outputs DTCs. Perform
troubleshooting with the "SFI System 10-2".
1.PERFORM ACTIVE TEST BY HAND-HELD TESTER
a. Operate the hand-held tester according to the steps on the display and select the "ACTIVE TEST".
METER:
ACTIVE TEST REFERENCE

OK:
Needle indication is normal.
NG: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
OK: GO TO NEXT STEP
2.READ VALUE OF HAND-HELD TESTER (ENGINE COOLANT)
a. Operate the hand-held tester according to the steps on the display and select the "DATA LIST".
ENGINE:
DATA LIST REFERENCE
OK:
Coolant temperature displayed on the tester is between 80°C (176°F) and 95°C (203°F) after
warning up.
NG: GO TO ENGINE CONTROL SYSTEM (SEE REPLACEMENT
)
OK: GO TO NEXT STEP
3.REPLACE COMBINATION METER ASSY
OK:
Normal operation
NG: GO TO ENGINE CONTROL SYSTEM (SEE REPLACEMENT
)
OK: END
WIRING DIAGRAM
ItemTest DetailsDiagnostic Note
COOLANT TEMPLOW /NORMAL /HI-
ItemMeasurement Item/ Range
(Display)Normal ConditionDiagnostic Note
COOLANT
TEMPCoolant Temperature / Min.: -
40°C (-40°F), Max.: 140°C
(284 °F)After warming up: 80
to 95°C (176 to 203°
F)If the value is "-40°C (-40°F)" or
"140°C (284°F)", sensor circuit is
open or shorted.

psi), and check that the pressure does not drop.
If the pressure drops, check the hoses, radiator and water pump for leaks. If no external leaks are found,
check the heater core, cylinder block and head.
2.CHECK ENGINE COOLANT LEVEL AT RESERVOIR
a. Check that the engine coolant level is between the LOW and FULL lines when the engine is cold.
If the engine coolant is low, check for leaks and add "TOYOTA Super Long Life Coolant" to the
FULL line.
If "TOYOTA Super Long Life Coolant" is not available, use a similar high quality ethylene glycol
based non-silicate, non-amino, non-nitrite and non-borate coolant with long-life hybrid organic acid
technology. Do not substitute plain water for engine coolant.
3.CHECK ENGINE COOLANT QUALITY
a. Remove the radiator cap.
b. Check if there are any excessive deposits of rust or scale around the radiator cap and radiator filler
hole, Also, the coolant should be free from oil.
HINT:
If excessively dirty, clean the coolant passage and replace the coolant.
c. Reinstall the radiator cap.
INSPECTION
1. INSPECT THERMOSTAT
HINT:
The thermostat is stamped with the valve openin
g temperature.

ON-VEHICLE INSPECTION
1.CHECK COOLING FAN SYSTEM
a. Look at the chart below. Check that when the cooling fan is in the condition on the left, its
operation is what is written on the right.
Standard when engine coolant temperature is below 82°C (180°F):
CONDITION AND OPERATION SPECIFICATION
If the fan does not operate as specified, proceed to next step.
2.INSPECT COOLING FAN MOTOR
a. Remove the air cleaner inlet No. 1.
b. Disconnect the 2 connectors.
c. Connect the battery and ammeter.
d. Check that the fan rotates smoothly, and then check the amperage on the ammeter.
Standard: 9.2 to 11.0 A at 20° C (68° F)
If the result is not as specified, replace the fan motor.
If the fan operates, proceed to the next step.
ConditionOperation (Fan Speed)
Ignition ON at engine stoppingNot rotating
A/C switch OFF at idle speedNot rotating
A/C switch ON at idle speedRotating (Low speed)
Disconnect ECT sensor connector at idle speedRotating (High speed)

c. Close the radiator drain plug.
d. Tighten the 2 drain cock plugs.
Torque: 13 Nm (130 kgf cm, 9 ft lbf)
Fig. 12: Loosening Radiator Drain Plug And Drain Cock Plugs

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
4.ADD ENGINE COOLANT
a. Slowly fill the cooling system with coolant.
Capacity: 9.5 liters (10.0 US qts, 8.4 lmp. qts)
HINT:
Use of improper coolants may damage the engine cooling system.
Use "TOYOTA Super Long Life Coolant" or similar high quality ethylene glycol based non-
silicate, non-amine, non-nitrite, and non-borate coolant with long-life hybrid organic acid
technology.
New Toyota vehicles are filled with TOYOTA Super Long Life Coolant (color is pink,
premixed ethylene-glycol concentration is approximately 50 % and freezing temperature is -
35° C (-31° F)). When replacing coolant, TOYOTA Super Long Life Coolant is

a. D position test:
Shift into the D position and fully depress the accelerator pedal and check the following points.
1. Check up-shift operation.
Check that 1 --> 2,2 --> 3,3 --> 4,4 --> 5 and 5 --> 6th up-shifts take place, and that the shift
points conform to the automatic shift schedule (see SERVICE DATA
).
HINT:
6th and 5th Gear Up-shift Prohibition Control
Engine coolant temperature is 55 °C (131 °F) or less and vehicle speed is at 51 km/h
(32 mph) or less. 4th Gear Up-shift Prohibition Control
Engine coolant temperature is 47 °C (117 °F) or less and vehicle speed is at 49 km/h
(30 mph) or less. Lock-up Prohibition Control
Brake pedal is depressed.
Accelerator pedal is released.
<00280051004a004c005100480003004600520052004f0044005100570003005700480050005300480055004400570058005500480003004c00560003001900130003008300260003000b001400170013000300830029000c0003005200550003004f004800
560056001100030003[
2. Check for shift shock and slip.
Check for shock and slip at the 1 --> 2,2 --> 3, 3 --> 4, 4 --> 5 and 5 --> 6th up-shifts.
3. Check for abnormal noise and vibration.
Check for abnormal noise and vibration when up-shifting from 1 --> 2, 2 --> 3, 3 --> 4, 4 -->
5 and 5 --> 6 while driving with the shift lever in the D position, and also check while driving
in the lock-up condition.
HINT:
The check for the cause of abnormal noise and vibration must be done thoroughly as it could
also be due to loss of balance in the differential, torque converter clutch, etc.
4. Check kick-down operation.
<0026004b00480046004e000300590048004b004c0046004f004800030056005300480048004700560003005a004b0048005100030057004b004800030015005100470003005700520003001400560057000f00030016005500470003005700520003001500
510047000f000300170057004b000300570052000300160055[d, 5th to 4th, and 6th to 5th
kick-downs take place while driving with the shift lever in the D position. Confirm that each
speed is within the applicable vehicle speed range indicated in the automatic shift schedule
(see SERVICE DATA
).
5. Check for abnormal shock and slip at kic
k-down.

a. Perform this drive pattern as one method to simulate the detection conditions of the ECT
malfunctions. (The DTCs may not be detected due the actual driving conditions. And some codes
may not be detected through this drive pattern.)
HINT:
Preparation for driving
Warm up the engine sufficiently. (Engine coolant temperature is 60 °C (140 °F) or higher)
Drive the vehicle when the atmospheric temperature is -10 °C (14 °F) or higher. (Malfunction is not
detected when the atmospheric temperature is -10 °C (14 °F) or less)
Notice in driving
Drive the vehicle through all gears.
Stop --> 1st --> 2nd --> 3rd --> 4th --> 5th --> 6th --> 6th (lock-up ON).
Perform engine brake test in the S position.
While driving in the 6(S) position and 6th gear lock-up, shift into the "-" position and down-shift
<0049005500520050000300190057004b000300570052000300180057004b000f000300180057004b000300570052000300170057004b000f000300170057004b0003005700520003001600550047000f000300160055004700030057005200030015005100
47000f00030015005100470003005700520003001400560057[.
<0026004b00480046004e00030057004b0044005700030057004b0048000300480051004a004c005100480003004500550044004e00480003005300480055004900520055005000560003005300550052005300480055004f005c0003005a004b0048005100
48005900480055000300470052005a005100100056004b004c[ft takes place.
Repeat the above driving pattern three times or more.