2003 LEXUS LS430 Ecm

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
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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

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. 181: Identifying Duty Ratio Pattern
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Fig. 182: DTC Reference Chart

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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

Fig. 185: Tester Condition Reference Chart
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NG: Go to step 3
OK: Go to next step
2.CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)
a. Connect the transmission wire connector to the transmission.
b. Disconnect the ECM connector.
c. Measure the resistance according to the value(s) in the table below.
Fig. 186: Disconnecting ECM Connector

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Standard:
TRANSMISSION WIRE - ECM - RESISTANCE TABLE
d. Measure the resistance according to the value(s) in the table below.
Standard (Check for short):
Fig. 187: Tester Connection Reference Chart

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NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (See ELECTRONIC CIRCUIT
INSPECTION PROCEDURE )
OK: REPLACE ECM (See REPLACEMENT
)
3.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.
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.
Tester ConnectionSpecified Condition 20°C (68°F)
E6 - 13 (SLU+) - E6 - 12 (SLU-)5.0 to 5.6 ohms
Tester ConnectionSpecified Condition 20°C (68°F)
1 - 25.0 to 5.6 ohms

Fig. 194: Transmission Control Switch Reference Chart
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NG: REPLACE TRANSMISSION CONTROL SWITCH (See COMPONENTS
)
OK: Go to next step
4.CHECK HARNESS AND CONNECTOR (TRANSMISSION CONTROL SWITCH - ECM)
a. Connect the transmission control switch connector of shift lock control unit assy.
b. Turn the ignition switch to the ON position, and measure the voltage according to the value(s) in
the table below when the shift lever is moved to each position.

Fig. 195: Identifying ECM Connector Terminals
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Standard:
Fig. 196: Transmission Control Switch Reference Chart

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c. Turn the ignition switch to the LOCK position.
d. Disconnect the ECM connector.