LEXUS LS430 2003 Factory Repair Manual

Condition (A)
TYPICAL ENABLING CONDITIONS TABLE - A
Condition (B)
TYPICAL ENABLING CONDITIONS TABLE - B
Condition (C)
TYPICAL ENABLING CONDITIONS TABLE - C
Condition (D)
TYPICAL ENABLING CONDITIONS TABLE - D
TYPICAL MALFUNCTION THRESHOLDS
Both of the following conditions are met: Condition (A), and Condition (B), (C) or (D)
Malfunction (A)
TYPICAL MALFUNCTION THRESHOLDS TABLE - MALFUNCTION A
Malfunction (B)
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 at 2,000 rpm (Conditions vary with
engine speed)
ECM selected gear4th
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)
Current ECM selected gear5th
Last ECM selected gear4th
Vehicle speed (During transition from 4th to 5th
gear)Less than 100 km/h (62.2 mph)
ECM selected gear5th
Engine speed-Turbine speed (NE-NT) (After
transition to 5th gear)Less than 150 rpm
Vehicle speed (After transition to 5th gear)Less than 100 km/h (62.2 mph)
Turbine speed/Output speed (NT/NO)3.08 or more and 7.50 or less (This means actual
gear is 1st)

TYPICAL MALFUNCTION THRESHOLDS TABLE - MALFUNCTION B
Malfunction (C)
TYPICAL MALFUNCTION THRESHOLDS TABLE - MALFUNCTION C
Malfunction (D)
TYPICAL MALFUNCTION THRESHOLDS TABLE - MALFUNCTION D
INSPECTION PROCEDURE
1.CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P0781)
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 "P0781" 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.PERFORM ACTIVE TEST BY HAND-HELD TESTER
HINT:
Performing the ACTIVE TEST using the hand-held tester allows the relay, VSV, actuator and so on to
operate without parts removal. Performin
g the ACTIVE TEST as the first step of troubleshooting is one
Turbine speed/Output speed (NT/NO)1.23 or more and 1.48 or less (This means actual
gear is 3rd)
Turbine speed - Output speed x 4th gear ratio (NT -
NO x 4th gear ratio)1,000 rpm or more
Turbine speed - Output speed x 5th gear ratio (NT -
NO x 5th gear ratio)1,000 rpm or more
Display (DTC output)Proceed to
Only "P0781" is outputA
"P0781" and other DTCsB

method to shorten labor time.
It is possible to display the DATA LIST during the ACTIVE TEST.
a. Warm up the engine.
b. Turn the ignition switch off.
c. Connect the hand-held tester together with the CAN VIM (controller area network vehicle interface
module) to the DLC3.
d. Turn the ignition switch to the ON position.
e. Push the "ON" button of the hand-held tester.
f. Clear the DTC.
g. Select the item "DIAGNOSIS/ENHANCED OBD II/ACTIVE TEST/SHIFT".
h. According to the display on tester, perform the "ACTIVE TEST".
HINT:
While driving, the shift position can be forcibly changed with the hand-held tester.
Comparing the shift position commanded by the ACTIVE TEST with the actual shift position enables
you to confirm the problem (see FAIL
-SAFE CHART ).
Fig. 130: Test Item Reference Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
HINT:
This test can be conducted when the vehicle speed is 50 km/h (31 mph) or less.
The 4th to 5th and 5th to 6th up-shiftings must be performed with the accelerator pedal released.
The 6th to 5th and 5th to 4th down-shiftings must be performed with the accelerator pedal released.
Do not operate the accelerator pedal for at least 2 seconds after shifting and do not shift
successively.
The shift position commanded by the ECM is shown in the DATA LIST/SHIFT display on the
hand-held tester.
Gear positions in the event of a solenoid valve mechanical problem:

Fig. 131: Gear Position Specification
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK:
Gear position changes in accordance with the tester command.
NG: REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSY (See step 6 on
REPLACEMENT
)
OK: Go to next step
3.PERFORM ACTIVE TEST BY HAND - HELD TESTER
SST 09992-00095 (09992-00231, 09992-00271)
HINT:
Performing the intelligent tester's ACTIVE TEST allows relay, VSV, actuator and other items to be
operated without removing any parts. Performing the ACTIVE TEST early in troubleshooting is one way
to save time. The DATA LIST can be displayed during the ACTIVE TEST.
a. Remove the test plug on the transmission case center right side and connect SST.
b. Connect the hand - held tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
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.

Fig. 132: Measuring Line Pressure With SST
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
ITEM DIAGNOSTIC NOTE CHART

NG: REPLACE SHIFT SOLENOID VALVE SLT
OK: GO TO NEXT STEP
4.CLEAR THE DTC AND RUNNING TEST
a. Clear the DTC, and check DTC again after conducting the "MONITOR DRIVE PATTERN FOR
ECT TEST" (see MONITOR DRIVE PATTERN
).
OK:
No DTC code
NG: REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSY (See step 6 on
REPLACEMENT
)
OK: END
DTC P0973, P0974: SHIFT SOLENOID "A" CONTROL CIRCUIT LOW/HIGH (SHIFT SOLENOID
VALVE S1)
CIRCUIT DESCRIPTION
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 )

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. (In case of an open or short circuit, the ECM stops sending current to the
circuit.) Fail safe function (see FAIL
-SAFE CHART ).
Fig. 133: DTC Reference Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
MONITOR DESCRIPTION
These DTCs indicate an open or short in the shift solenoid valve S1 circuit. When there is an open or short
circuit in any shift solenoid valve circuit, the ECM detects the problem and illuminates the MIL and stores the
DTC. When the shift solenoid valve S1 is on, if resistance is 8 ohms or less, the ECM determines there is a
short in the shift solenoid valve S1 circuit.
When the shift solenoid valve S1 is off, if resistance is 100 kohms or more, the ECM determines there is an
open in the shift solenoid valve S1 circuit (see FAIL
-SAFE CHART ).
MONITOR STRATEGY
MONITOR STRATEGY TABLE
TYPICAL ENABLING CONDITIONS
P0973: Range check (Low resistance)
TYPICAL ENABLING CONDITIONS TABLE - P0973
Related DTCsP0973: Shift solenoid valve S1 /Range check (Low
resistance) P0974: Shift solenoid valve S1 /Range
check (High resistance)
Required sensors/ComponentsShift solenoid valve S1
Frequency of operationContinuous
Duration0.064 sec. or more
MIL operationImmediate
Sequence of operationNone
The monitor will run whenever this DTC is not
present.See LIST OF DISABLE A MONITOR

P0974: Range check (High resistance)
TYPICAL ENABLING CONDITIONS TABLE - P0974
TYPICAL MALFUNCTION THRESHOLDS
P0973: Range check (Low resistance)
TYPICAL MALFUNCTION THRESHOLDS - P0973
P0974: Range check (High resistance)
TYPICAL MALFUNCTION THRESHOLDS TABLE - P0974
COMPONENT OPERATING RANGE
COMPONENT OPERATING RANGE TABLE
WIRING DIAGRAM
Fig. 134: DTC P0973, P0974 - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
Shift solenoid valve S1ON
The monitor will run whenever this DTC is not
present.See LIST OF DISABLE A MONITOR
Shift solenoid valve S1OFF
Shift solenoid valve S1 resistance8 ohms or less
Shift solenoid valve S1 resistance100 kohms or more
Shift solenoid valve S1Resistance: 11 to 15 ohms at 20°C (68°F)

1.INSPECT TRANSMISSION WIRE (S1)
a. Disconnect the transmission wire connector from the transmission.
b. Measure the resistance according to the value(s) in the table below.
Fig. 135: Identifying Transmission Wire Terminals

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Standard:
TRANSMISSION WIRE (S1) - RESISTANCE TABLE
NG: Go to step 3
OK: Go to next step
2.CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)
a. Connect the transmission connector to the transmission.
b. Disconnect the connector from the ECM.
Tester ConnectionSpecified Condition 20°C (68°F)
8 - Body ground11 to 15ohms

c. Measure the resistance according to the value(s) in the table below.
Fig. 136: Disconnecting Connector From ECM

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Standard:
TRANSMISSION WIRE - ECM - RESISTANCE TABLE
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (See ELECTRONIC CIRCUIT
INSPECTION PROCEDURE )
OK: REPLACE ECM (See REPLACEMENT
)
3.INSPECT SHIFT SOLENOID VALVE (S1)
a. Remove the shift solenoid valve S1.
b. Measure the resistance according to the value(s) in the table below.
Standard:
Tester ConnectionSpecified Condition 20°C (68°F)
E6 - 19 (S1) - Body ground11 to 15ohms