automatic transmission LEXUS LS430 2003 Factory Service Manual
[x] Cancel search | Manufacturer: LEXUS, Model Year: 2003, Model line: LS430, Model: LEXUS LS430 2003Pages: 4500, PDF Size: 87.45 MB
Page 2742 of 4500

Fig. 59: DTC Reference Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
MONITOR DESCRIPTION
These DTCs indicate an open or short in the automatic transmission fluid (ATF) temperature sensor circuit. The
automatic transmission fluid (ATF) temperature sensor converts ATF temperature to an electrical resistance
value. Based on the resistance, the ECM determines the ATF temperature, and the ECM detects an opens or
shorts in the ATF temperature circuit. If the resistance value of the ATF temperature is less than 79ohms*1 or
more than 156kohms*2, the ECM interprets this as a fault in the ATF sensor or wiring. The ECM will turn on
the MIL and store the DTC.
*1: 150°C (302°F) or more is indicated regardless of the actual ATF temperature.
*2: -40°C (-40°F) is indicated regardless of the actual ATF temperature.
HINT:
The ATF temperature can be checked on the OBD II scan tool or hand-held tester display.
MONITOR STRATEGY
MONITOR STRATEGY TABLE
Related DTCsP0710: ATF temperature sensor/Range check
(Chattering) P0712: ATF temperature
sensor/Range check (Low resistance) P0713: ATF
temperature sensor/Range check (High resistance)
Required sensors/ComponentsATF temperature sensor (TFT sensor)
Frequency of operationContinuous
Duration0.5 sec.
MIL operationImmediate
Sequence of operationNone
Page 2748 of 4500

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Standard (Check for short):
Fig. 65: Tester Connection Reference Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (See ELECTRONIC CIRCUIT
INSPECTION PROCEDURE )
OK: REPLACE ECM (See REPLACEMENT
)
DTC P0711: TRANSMISSION FLUID TEMPERATURE SENSOR "A" PERFORMANCE
CIRCUIT DESCRIPTION
See CIRCUIT DESCRIPTION .
Fig. 66: DTC Reference Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
MONITOR DESCRIPTION
This DTC indicates that there is a problem with output from the automatic transmission fluid (ATF) temperature
sensor and that the sensor itself is defective. The ATF temperature sensor converts the ATF temperature to an
electrical resistance value. Based on the resistance, the ECM determines the ATF temperature and detects an
opens or shorts in the ATF temperature circuit or a fault of the ATF temperature sensor. After running the
vehicle for a certain period, the ATF temperature should increase. If the ATF temperature is below 10°C (50°F)
after running the vehicle for a certain period, the ECM interprets this as a fault, and turns on the MIL.
MONITOR STRATEGY
Page 2751 of 4500

It is not necessary to inspect the circuit when P0711 is set.
1.CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P0711)
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 "DIAGNOSIS/ENHANCED OBD II/DTC INFO/CURRENT CODES".
d. Read the DTCs using the hand-held tester.
Result:
DTC OUTPUT RESULT TABLE
HINT:
If any other codes besides "P0711" are output, perform troubleshooting for those DTCs first.
B: GO TO RELEVANT DTC CHART (See DIAGNOSTIC TROUBLE CODE CHART
)
A: Go to next step
2.CHECK TRANSMISSION FLUID LEVEL (See ADJUSTMENT
- AUTOMATIC
TRANSMISSION FLUID )
OK:
Automatic transmission fluid level is correct.
NG: ADD FLUID
OK: REPLACE TRANSMISSION WIRE (See step 5 on REPLACEMENT
)
DTC P0717: TURBINE SPEED SENSOR CIRCUIT NO SIGNAL
CIRCUIT DESCRIPTION
This sensor detects the rotation speed of the turbine which shows the input revolution of transmission. By
comparing the input turbine speed signal (NT) with the counter gear speed sensor signal (SP2), the ECM detects
the shift timing of the gears and appropriately controls the engine torque and hydraulic pressure according to
various conditions. Thus, providin
g smooth gear shift.
Display (DTC output)Proceed to
Only "P0711" is outputA
"P0711" and other DTCsB
Page 2764 of 4500

OK: REPLACE ECM (See REPLACEMENT)
DTC P0729: GEAR 6 INCORRECT RATIO
SYSTEM DESCRIPTION
The ECM uses signals from the output speed sensor SP2 and input speed sensor NT to detect the actual gear
position (1st, 2nd, 3rd, 4th, 5th or 6th gear). Then the ECM compares the actual gear with the shift schedule in
the ECM memory to detect mechanical problems of the shift solenoid valves, valve body or automatic
transmission (clutch, brake or gear, etc.).
Fig. 83: Identifying Valve Body
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Page 2784 of 4500

OK:
The torque converter clutch operates normally.
NG: REPLACE TORQUE CONVERTER CLUTCH ASSY
OK: REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSY (See COMPONENTS
)
DTC P0756: SHIFT SOLENOID "B" PERFORMANCE (SHIFT SOLENOID VALVE S2)
SYSTEM DESCRIPTION
The ECM uses signals from the output shaft speed sensor and input speed sensor to detect the actual gear
position (1st, 2nd, 3rd, 4th, 5th or 6th gear).
Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical
problems of the shift solenoid valves and valve body.
Fig. 101: DTC Reference Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
HINT:
Gear positions in the event of a solenoid valve mechanical problem:
Page 2791 of 4500

TABLE )
OK:
There are no foreign objects on each valve and they operate smoothly.
NG: REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSY (See step 6 on
REPLACEMENT
)
OK: Go to next step
4.INSPECT TORQUE CONVERTER CLUTCH ASSY (See INSPECTION
)
OK:
The torque converter clutch operates normally.
NG: REPLACE TORQUE CONVERTER CLUTCH ASSY
OK: REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSY (See COMPONENTS
)
DTC P0761: SHIFT SOLENOID "C" PERFORMANCE (SHIFT SOLENOID VALVE S3)
SYSTEM DESCRIPTION
The ECM uses signals from the output shaft speed sensor and input speed sensor to detect the actual gear
position (1st, 2nd, 3rd, 4th, 5th or 6th gear).
Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical
problems of the shift solenoid valves and valve body.
Page 2799 of 4500

c. Start the engine and warm it up.
d. Measure the line pressure with SST.
e. Turn the hand - held tester ON.
f. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST.
g. Follow the instructions on the tester and perform the ACTIVE TEST.
h. Measure the line pressure with SST.
ITEM DIAGNOSTIC NOTE CHART
NG: REPLACE SHIFT SOLENOID VALVE SLT
OK: GO TO NEXT STEP
3.INSPECT SHIFT SOLENOID VALVE (S3)
a. Remove the shift solenoid valve S3.
b. Measure the resistance according to the value(s) in the table below.
Standard:
SHIFT SOLENOID VALVE (S3) - RESISTANCE TABLE
ItemTest DetailsDiagnostic Note
LINE PRESS UP(1)
[Test Details]
Operate shift solenoid SLT and
raise line pressure
[Vehicle Condition]
Vehicle stopped
IDL: ON
HINT:
OFF: Line pressure up (when
Active Test "LINE PRESS UP" is
performed, ECM commands SLT
solenoid to turn OFF)
ON: No action (normal operation)
-
HINT:
The pressure values in ACTIVE TEST and HYDRAULIC TEST are different from each other.
Normally, the line pressure detected in the ACTIVE TEST is approximately half of the value
detected in the HYDRAULIC TEST's stall test.
(1)"LINE PRESS UP" in the ACTIVE TEST is performed to check the line pressure change by
connecting SST to the automatic transmission, which is used in the HYDRAULIC TEST
(see )
Page 2801 of 4500

There are no foreign objects on each valve and they operate smoothly.
NG: REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSY (See step 6 on
REPLACEMENT
)
OK: Go to next step
5.INSPECT TORQUE CONVERTER CLUTCH ASSY (See INSPECTION
)
OK:
The torque converter clutch operates normally.
NG: REPLACE TORQUE CONVERTER CLUTCH ASSY
OK: REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSY (See COMPONENTS
)
DTC P0766: SHIFT SOLENOID "D" PERFORMANCE (SHIFT SOLENOID VALVE S4)
SYSTEM DESCRIPTION
The ECM uses signals from the output shaft speed sensor and input speed sensor to detect the actual gear
position (1st, 2nd, 3rd, 4th, 5th or 6th gear).
Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical
problems of the shift solenoid valves and valve body.
Fig. 112: DTC Reference Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
HINT:
Gear positions in the event of a solenoid valve mechanical problem:
Page 2808 of 4500

NG: REPLACE SHIFT SOLENOID VALVE SLT
OK: GO TO NEXT STEP
3.INSPECT SHIFT SOLENOID VALVE (S4)
a. Remove the shift solenoid valve S4.
b. Measure the resistance according to the value(s) in the table below.
Standard:
SHIFT SOLENOID VALVE (S4) - RESISTANCE TABLE
c. Connect positive (+) lead to the terminal of solenoid connector, negative (-) lead to the solenoid
body.
OK:
The solenoid makes an operating noise.
ItemTest DetailsDiagnostic Note
LINE PRESS UP(1)
[Test Details]
Operate shift solenoid SLT and
raise line pressure
[Vehicle Condition]
Vehicle stopped
IDL: ON
HINT:
OFF: Line pressure up (when
Active Test "LINE PRESS UP" is
performed, ECM commands SLT
solenoid to turn OFF)
ON: No action (normal operation)
-
HINT:
The pressure values in ACTIVE TEST and HYDRAULIC TEST are different from each other.
Normally, the line pressure detected in the ACTIVE TEST is approximately half of the value
detected in the HYDRAULIC TEST's stall test.
(1)"LINE PRESS UP" in the ACTIVE TEST is performed to check the line pressure change by
connecting SST to the automatic transmission, which is used in the HYDRAULIC TEST
(see )
Tester ConnectionSpecified Condition 20°C (68°F)
Solenoid Connector (S4) - Solenoid Body (S4)11 to 15ohms
Page 2811 of 4500

NG: REPLACE SHIFT SOLENOID VALVE (SL2)
OK: Go to next step
5.INSPECT TRANSMISSION VALVE BODY ASSY (See chapter 2 in PROBLEM SYMPTOMS
TABLE )
OK:
There are no foreign objects on each valve and they operate smoothly.
NG: REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSY (See step 6 on
REPLACEMENT
)
OK: Go to next step
6.INSPECT TORQUE CONVERTER CLUTCH ASSY (See INSPECTION
)
OK:
The torque converter clutch operates normally.
NG: REPLACE TORQUE CONVERTER CLUTCH ASSY
OK: REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSY (See COMPONENTS
)
DTC P0778: PRESSURE CONTROL SOLENOID "B" ELECTRICAL (SHIFT SOLENOID VALVE
SL2)
CIRCUIT DESCRIPTION
Shifting from 1st to 6th is performed in combination with "ON" and "OFF" operation of the shift solenoid
valves SL1, SL2, S1, S2, S3, S4 and SR which is controlled by the ECM. If an open or short circuit occurs in
either of the shift solenoid valves, the ECM controls the remaining normal shift solenoid valve to allow the
vehicle to be operated smoothly (see FAIL
-SAFE CHART ).
Fig. 119: DTC Reference Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
MONITOR DESCRIPTION