2003 LEXUS LS430 coolant temperature

OFF malfunction (A)
TYPICAL ENABLING CONDITIONS TABLE - OFF MALFUNCTION A
OFF malfunction (B)
TYPICAL ENABLING CONDITIONS TABLE - OFF MALFUNCTION B
TYPICAL MALFUNCTION THRESHOLDS
Both of the following conditions are met: OFF malfunctions (A) and (B)
OFF malfunction (A)
TYPICAL MALFUNCTION THRESHOLDS TABLE - OFF MALFUNCTION A
The monitor will run whenever this DTC is not
present.See LIST OF DISABLE A MONITOR
Turbine speed sensor circuitNot circuit malfunction
Output speed sensor circuitNot circuit malfunction
Shift solenoid valve S1 circuitNot circuit malfunction
Shift solenoid valve S2 circuitNot circuit malfunction
Shift solenoid valve S3 circuitNot circuit malfunction
Shift solenoid valve S4 circuitNot circuit malfunction
Shift solenoid valve SR circuitNot circuit malfunction
Shift solenoid valve SL1 circuitNot circuit malfunction
Shift solenoid valve SL2 circuitNot circuit malfunction
ECT (Engine coolant temperature) sensor circuitNot circuit malfunction
KCS sensor circuitNot circuit malfunction
ETCS (Electric throttle control system)Not system down
Transmission range"D"
ECT40°C (104°F) or more
Spark advance from Max. retard timing by KCS
control0° CA or more
EngineStarting
ECM selected gear5th
Vehicle speed2 km/h (1.2 mph) or more
Throttle valve opening angle6.5% or more at 2,000 rpm (Conditions vary with
engine speed)
ECM selected gear6th
Vehicle speed2 km/h (1.2 mph) or more
Throttle valve opening angle6.5% or more at 2,000 rpm (Conditions vary with
engine speed)

The ECM commands gear shifts by turning the shift solenoid valves "ON/OFF" and switching oil pressure to
the valves in the valve body.
The ECM calculates the "actual" transmission gear by comparing the signals from the input speed sensor (NT)
and the output speed sensor (SP2). The ECM can detect many mechanical problems in the shift solenoids, valve
body, and the transmission clutches, brakes, and gears. If the ECM detects that the actual gear position and the
commanded gear position are different, it will illuminate the MIL and store the DTC.
MONITOR STRATEGY
MONITOR STRATEGY TABLE
TYPICAL ENABLING CONDITIONS
The following items are common to all conditions below.
TYPICAL ENABLING CONDITIONS TABLE
Related DTCsP0781: Valve body/Rationality check
Required sensors/ComponentsValve body, Automatic transmission assembly
Frequency of operationContinuous
Duration<0026005200510047004c0057004c005200510003000b0024000c00030044005100470003000b0025000c00030013001100170003005600480046001100030026005200510047004c0057004c005200510003000b0026000c00030016000300560048004600
110003[
Condition (C) 1 sec.
MIL operation2 driving cycles
Sequence of operationNone
The monitor will run whenever this DTC is not
present.See LIST OF DISABLE A MONITOR
Turbine speed sensor circuitNot circuit malfunction
Output speed sensor circuitNot circuit malfunction
Shift solenoid valve S1 circuitNot circuit malfunction
Shift solenoid valve S2 circuitNot circuit malfunction
Shift solenoid valve S3 circuitNot circuit malfunction
Shift solenoid valve S4 circuitNot circuit malfunction
Shift solenoid valve SR circuitNot circuit malfunction
Shift solenoid valve SL1 circuitNot circuit malfunction
Shift solenoid valve SL2 circuitNot circuit malfunction
ECT (Engine coolant temperature) sensor circuitNot circuit malfunction
KCS sensor circuitNot circuit malfunction
ETCS (Electric throttle control system)Not system down
Transmission range"D"
ECT40°C (104°F) or more
Spark advance from Max. retard timing by KCS
control0° CA or more
EngineStarting

OFF malfunction (A)
TYPICAL ENABLING CONDITIONS TABLE - OFF MALFUNCTION A
OFF malfunction (B)
TYPICAL ENABLING CONDITIONS TABLE - OFF MALFUNCTION B
ON malfunction
TYPICAL ENABLING CONDITIONS TABLE - ON MALFUNCTION
Shift solenoid valve S1 circuitNot circuit malfunction
Shift solenoid valve S2 circuitNot circuit malfunction
Shift solenoid valve S3 circuitNot circuit malfunction
Shift solenoid valve S4 circuitNot circuit malfunction
Shift solenoid valve SR circuitNot circuit malfunction
Torque converter clutch pressure control solenoid
circuitNot circuit malfunction
KCS sensor circuitNot circuit malfunction
ETCS (Electric throttle control system)Not system down
Transmission shift position"D"
ECT (Engine coolant temperature)40°C (104°F) or more
Spark advance from Max. retard timing by KCS
control0° CA or more
EngineStarting
ECM selected gear4th, 5th or 6th
Vehicle speed25 km/h (15.5 mph) or more
Shift solenoid valve S1 circuitNot circuit malfunction
Shift solenoid valve S3 circuitNot circuit malfunction
Shift solenoid valve S4 circuitNot circuit malfunction
Shift solenoid valve SL2 circuitNot circuit malfunction
1 - 2 shift valveNot circuit malfunction
ECM lock - up commandON (SLU pressure: 513 kPa or more)
Duration time from lock-up on command3 sec. or more
Vehicle speedLess than 100 km/h (62.2 mph)
ECM selected gear2nd
Vehicle speed2 km/h (1.2 mph) or more
Output speed2nd --> 1st down shift point or more
Throttle valve opening angle6.5% or more (Varies with engine speed)
ECM lock - up commandOFF (SLU pressure: less than 4 kPa)
Duration time from lock-up on command3 sec. or more

Fig. 10: Inspecting Throttle Body Assy
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
a. Measure the resistance between the terminals.
STANDARD:
If the result is not as specified, replace the throttle body assy.
5.INSPECT ENGINE COOLANT TEMPERATURE SENSOR
Tester ConnectionConditionSpecified Condition
2 (M+) - 1 (M-)20°C (68°F)0.3 to 100 ohms
5 (VC) - 3 (E2)20°C (68°F)1.2 to 3.2 kohms

Fig. 11: Inspecting Engine Coolant Temperature Sensor
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
a. Measure the resistance between the terminals.

INSPECTION
1.CHECK EVAPORATOR AND HEATER RADIATOR FINS FOR FOREIGN MATTER
If foreign matter is attached to the fin, blow it off with compressed air.
2.CHECK FITTINGS FOR CRACKS OR SCRATCHES
a. Repair as necessary.
3.INSPECT EVAPORATOR TEMPERATURE SENSOR CIRCUIT (See DTC B1413:
EVAPORATOR TEMPERATURE SENSOR CIRCUIT )
4.INSPECT COOL AIR BYPASS DAMPER POSITION SENSOR CIRCUIT (DRIVER SIDE) (See
DTC B1434: MAX COOL DAMPER POSITION SENSOR CIRCUIT (DRIVER SIDE)
)
5.INSPECT COOL AIR BYPASS DAMPER CONTROL SERVOMOTOR CIRCUIT (DRIVER
SIDE) (See COOL AIR BYPASS DAMPER CONTROL SERVOMOTOR CIRCUIT (DRIVER
SIDE) )
6.INSPECT COOL AIR BYPASS DAMPER POSITION SENSOR CIRCUIT (PASSENGER SIDE)
(See COOL AIR BYPASS DAMPER CONTROL SERVOMOTOR CIRCUIT (PASSENGER
SIDE) )
7.INSPECT COOL AIR BYPASS DAMPER CONTROL SERVOMOTOR CIRCUIT (PASSENGER
SIDE) (SEE COOL AIR BYPASS DAMPER CONTROL SERVOMOTOR CIRCUIT
(PASSENGER SIDE) )
8.INSPECT WATER VALVE CONTROL SERVOMOTOR CIRCUIT (See WATER VALVE
CONTROL SERVOMOTOR CIRCUIT )
9.INSPECT AIR VENT MODE DAMPER CONTROL SERVOMOTOR CIRCUIT (See AIR VENT
MODE DAMPER CONTROL SERVOMOTOR CIRCUIT )
10.INSPECT AIR MIX DAMPER CONTROL SERVOMOTOR CIRCUIT (See AIR MIX DAMPER
CONTROL SERVOMOTOR CIRCUIT )
OVERHAUL
HINT:
Installation is in the reverse order of removal.
See COMPONENTS .
1.DISCONNECT NEGATIVE TERMINAL CABLE FROM BATTERY
2.EVACUATE REFRIGERANT HFC-134A (R134A) (See REPLACEMENT
)
3.DRAIN ENGINE COOLANT FROM RADIATOR
HINT:
It is not necessar
y to drain out all coolant.