LEXUS LS430 2003 Factory Repair Manual

relay valve and locks the torque converter clutch.
If the ECM detects no lock-up after lock-up has been requested or if it detects lock-up when it is not requested,
the ECM interprets this as a fault in the shift solenoid valve SLU or lock-up system performance.
The ECM will turn on the MIL and store the DTC.
Example:
When any of the following is met, the system judges it as a malfunction.
a. There is a difference in rotation between before and after torque converters even when the ECM
commands lock-up.
(Engine speed is at least 75 rpm greater than input turbine speed.)
b. There is no difference in rotation between before and after torque converters even when the ECM
commands lock-up off.
(The difference between engine speed and input turbine speed is less than 35 rpm.)
MONITOR STRATEGY
Fig. 176: Monitor Strategy Specification Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
TYPICAL ENABLING CONDITIONS
The following items are common to all conditions below.
TYPICAL ENABLING CONDITIONS TABLE
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

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

TYPICAL MALFUNCTION THRESHOLDS
Both of the following conditions are met: OFF malfunction (A) and (B)
OFF malfunction (A)
TYPICAL MALFUNCTION THRESHOLDS TABLE - OFF MALFUNCTION A
OFF malfunction (B)
TYPICAL MALFUNCTION THRESHOLDS TABLE - OFF MALFUNCTION B
ON malfunction
2 detections are necessary per driving cycle:
1st detection; temporary flag ON
2md detection; pending fault code ON
Vehicle speed must be under 10 km/h (6.2 mph) once before 2nd detection.
TYPICAL MALFUNCTION THRESHOLDS TABLE - ON MALFUNCTION
COMPONENT OPERATING RANGE
COMPONENT OPERATING RANGE TABLE
INSPECTION PROCEDURE
HINT:
Performing the ACTIVE TEST using the hand-held tester allows the relay, VSV, actuator and so on to operate
without parts removal. Performing the ACTIVE TEST as the first step of troubleshooting is one method to
shorten labor time.
It is possible to display the DATA LIST during the ACTIVE TEST.
Throttle valve opening angle9% or more
Vehicle speedLess than 60 km/h (37.3 mph)
Engine speed - Turbine speed (NE - NT)70 rpm or more
Engine speed - Turbine speed (NE - NT)Not 3.08 to 7.50
Engine speed - Turbine speed| (|NE - NT|)Less than 35 rpm
Speed sensor (NT)Input speed is equal to engine speed when lock-up
ON.

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/LOCK UP".
h. According to the display on tester, perform the "ACTIVE TEST".
Fig. 177: Test Item Reference Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
HINT:
This test can be conducted when the vehicle speed is 58 km/h (36 mph) or more.
This test can be conducted with the 5th or 6th gear.
i. Lightly depress the accelerator pedal and check that the engine speed does not change abruptly.
HINT:
When changing the accelerator pedal opening angle while driving, if the engine speed does not change,
lock-up is on.
Slowly release, but not fully, the accelerator pedal in order to decelerate. (Fully releasing the pedal will
close the throttle valve and loc
k-up may be turned off automatically.)

Fig. 178: Identifying Accelerator Pedal Opening Angle Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
1.CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P2757)
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 "P2757" 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.INSPECT SHIFT SOLENOID VALVE (SLU)
a. Remove the shift solenoid valve SLU.
b. Measure the resistance according to the value(s) in the table below.
Display (DTC output)Proceed to
Only "P2757" is outputA
"P2757" and other DTCsB

Fig. 179: Inspecting Shift Solenoid Valve (SLU)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Standard:

SHIFT SOLENOID VALVE (SLU) - RESISTANCE TABLE
c. Connect the positive (+) lead with a 21 W bulb to terminal 2 and the negative (-) lead to terminal 1
of the solenoid valve connector, then check the movement of the valve.
OK:
The solenoid makes an operating noise.
NG: REPLACE SHIFT SOLENOID VALVE (SLU)
OK: Go to next step
3.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
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 P2759: TORQUE CONVERTER CLUTCH PRESSURE CONTROL SOLENOID CONTROL
CIRCUIT ELECTRICAL (SHIFT SOLENOID VALVE SLU)
CIRCUIT DESCRIPTION
The amount of current flow to the solenoid is controlled by the (*) duty ratio of the ECM output signal. The
hi
gher the duty ratio becomes, the higher the lock-up hydraulic pressure becomes during the lock-up operation.
Tester ConnectionSpecified Condition 20°C (68°F)
1 - 25.0 to 5.6 ohms

Fig. 180: Identifying Lock-Up Operation Pressure Graph
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
(*) Duty Ratio
The duty ratio is the ratio of the period of continuity in one cycle. For example, if A is the period of continuity
in one c
ycle, and B is the period of non-continuity, then Duty Ratio = A/(A+B) x 100(%).

Fig. 181: Identifying Duty Ratio Pattern
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Fig. 182: DTC Reference Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
MONITOR DESCRIPTION
When an open or short in a shift solenoid valve (SLU) circuit is detected, the ECM determines there is a
malfunction. The ECM will turn on the MIL and store this DTC.
MONITOR STRATEGY
MONITOR STRATEGY TABLE
Related DTCsP2759: Shift solenoid valve SLU/Range check
Required sensors/ComponentsShift solenoid valve SLU
Frequency of operationContinuous

TYPICAL ENABLING CONDITIONS
TYPICAL ENABLING CONDITIONS TABLE
TYPICAL MALFUNCTION THRESHOLDS
TYPICAL MALFUNCTION THRESHOLDS TABLE
COMPONENT OPERATING RANGE
COMPONENT OPERATING RANGE TABLE
WIRING DIAGRAM
Fig. 183: DTC P2759 - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
Duration1 sec.
MIL operationImmediate
Sequence of operationNone
The monitor will run whenever this DTC is not
present.SEE LIST OF DISABLE A MONITOR
Solenoid current cut statusNot cut
CPU commanded duty ratio to SLU19% or more
Battery voltage11 V or more
Ignition switchON
StarterOFF
Solenoid status (SLU) from ICFail (Open or short)
Output signal dutyLess than 100%