LEXUS LS430 2003 Factory Repair Manual

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

This DTC indicates an open or short in the shift solenoid valve SL2 circuit. The ECM commands gear shifts by
turning the shift solenoid valves "ON/OFF". 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. And the ECM performs the
fail-safe function and turns the other shift solenoid valves in good condition "ON/OFF". (In case of an open or
short circuit, the ECM stops sending current to the circuit.)
While driving and shifting gears, if the ECM detects an open or short in the shift solenoid valve SL2 circuit, the
ECM determines there is a malfunction (see FAIL
-SAFE CHART ).
MONITOR STRATEGY
MONITOR STRATEGY TABLE
TYPICAL ENABLING CONDITIONS
TYPICAL ENABLING CONDITIONS TABLE
All of the following conditions are met: Condition (A) and (B)
Condition (A)
TYPICAL ENABLING CONDITIONS TABLE - A
Condition (B)
TYPICAL ENABLING CONDITIONS TABLE - B
TYPICAL MALFUNCTION THRESHOLDS
TYPICAL MALFUNCTION THRESHOLDS TABLE
Related DTCsP0778: Shift solenoid valve SL2/Range check
Required sensors/ComponentsShift solenoid valve SL2
Frequency of operationContinuous
Duration1 sec.
MIL operationImmediate
Sequence of operationNone
The monitor will run whenever this DTC is not
present.See LIST OF DISABLE A MONITOR
Battery voltage10 V or more and less than 12V
CPU commanded duty ratio to SL275% or more
Ignition SwitchON
StarterOFF
Battery voltage12 V or more
Ignition SwitchON
StarterOFF

COMPONENT OPERATING RANGE
COMPONENT OPERATING RANGE TABLE
WIRING DIAGRAM
Fig. 120: DTC P0778 - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
HINT:
The shift solenoid valve SL2 is turned on/off normally when the shift lever is in the D position:
GEARSHIFT SPECIFICATION TABLE
1.INSPECT TRANSMISSION WIRE (SL2)
a. Disconnect the transmission wire connector from the transmission.
b. Measure the resistance according to the value(s) in the table below.
Output signal duty100%
Output signal dutyLess than 100%
ECM
command
gearshift
1st2nd3rd4th5th6th
Shift solenoid
valve SL2ONONONONOFFOFF

Fig. 121: Identifying Transmission Wire Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Standard:
TRANSMISSION WIRE (SL2) - RESISTANCE TABLE
c. Measure the resistance according to the value(s) in the table below.
OK:
Standard (Check for short):
Tester ConnectionSpecified Condition 20°C (68°F)
10 (SL2+) - 2 (SL2-)5.0 to 5.6 ohms

Fig. 122: Tester Connection Reference Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
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.
c. Measure the resistance according to the value(s) in the table below.
Fig. 123: Disconnecting Connector From ECM

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Standard:
TRANSMISSION WIRE - ECM - RESISTANCE TABLE
d. Measure the resistance according to the value(s) in the table below.
Standard (Check for short):
Fig. 124: 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
)
3.INSPECT SHIFT SOLENOID VALVE (SL2)
a. Remove the shift solenoid valve SL2.
b. Measure the resistance according to the value(s) in the table below.
Standard:
SHIFT SOLENOID VALVE (SL2) - 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 - 11 (SL2+) - E6 - 10(SL2-)5.0 to 5.6 ohms
Tester ConnectionSpecified Condition 20°C (68°F)
1 - 25.0 to 5.6 ohms

Fig. 125: Inspecting Shift Solenoid Valve (SL2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE SHIFT SOLENOID VALVE (SL2)

OK: REPAIR OR REPLACE TRANSMISSION WIRE (See step 5 on REPLACEMENT)
DTC P0781: 1-2 SHIFT (1-2 SHIFT VALVE)
SYSTEM DESCRIPTION
The 1-2 shift valve performs shifting to 1st gear and other gears.
Fig. 126: Identifying Valve Body

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Fig. 127: DTC Reference Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
HINT:
Gear positions in the event of a solenoid valve mechanical problem:
Fig. 128: Gear Position Specification

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Gear position during fail-safe operation:
If any malfunction is detected, the ECM changes into the fail-safe mode to shift into the gear positions as shown
in the table below.
Fig. 129: Gear Position Specification

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
MONITOR DESCRIPTION
This DTC indicates that the 1-2 shift valve in the valve body is locked in the direction the spring compresses.

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