Lexus ES300 (2002 year). Manual - part 331

D02290

Line Pressure 
Control Pressure

Current Flow to Solenoid

BE4056

ON

OFF

1 cycle

D01875

GND

5 V/
Division

1 msec./Division

-

DIAGNOSTICS

ELECTRONIC CONTROLLED AUTOMATIC
TRANSAXLE [ECT]

05-443

596

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

DTC

P1760

LINEAR SOLENOID FOF LINE PRESSURE
CONTROL CIRCUIT MALFUNCTION

CIRCUIT DESCRIPTION

The throttle pressure that is applied to the primary regulator
valve (which modulates the line pressure) causes the solenoid
valve SLT, under electronic control, to precisely and minutely
modulate and generate the line pressure according the extent
of the accelerator pedal depressed or the output of engine pow-
er.
This reduces the function of the line pressure and provides
smooth shifting.
Upon receiving a signal of the throttle valve opening angle, the
ECM controls the line pressure by sending a predetermined (*)
duty ratio to the solenoid valve, modulating the line pressure
and generating throttle pressure.
(*): 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 cycle, and B
is the period of non-continuity, then
Duty Ratio=A/(A+B) x 100 (%)

DTC No.

DTC Detection Condition

Trouble Area

P1760

Condition (a) or (b) below is detected 1 sec. or more:

(a) SLT-

 

terminal: 0V

(b) SLT-

 

terminal: 12V

Open or short in line pressure control solenoid (SLT) circuit

Line pressure control solenoid (SLT)

ECM

Reference:
Check the waveform between terminals SLT+

 

and SLT-  during

the engine idling.

05280-04

C93636

ECM

SLT+

SLT-

E10

17

16

Y-R

Y-B

E1 Electronically Controlled 
Transmission Solenoid

E10

G

GR

SLT+

SLT-

1

E2

5

E2

05-444

-

DIAGNOSTICS

ELECTRONIC CONTROLLED AUTOMATIC
TRANSAXLE [ECT]

597

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

WIRING DIAGRAM

INSPECTION PROCEDURE

1

PERFORM ACTIVE TEST BY OBD II SCAN TOOL OR HAND-HELD TESTER

(a)

Warm up the engine.

(b)

Turn the ignition switch OFF.

(c)

Connect the OBD II scan tool or Hand-held tester to the DLC3.

(d)

Turn the ignition switch ON and push the OBD II scan tool or Hand-held tester main SW ON.

(e)

Select the item ”LINE PRESS UP” in the ACTIVE TEST and operate the shift solenoid SLT on the OBD
II scan tool or Hand-held tester.

NOTICE:
The values given below for ”Normal Condition” are representative values, so a vehicle may still be
normal even if its value differs from those listed here. Do not depend solely on the ”Normal Condi-
tion” here when deciding whether or not the part is faulty.

Item

Test Details

Diagnostic Note

LINE PRESS UP

[Test Details]
Operate the shift solenoid SLT and raise the line pressure.
[Vehicle Condition]

Vehicle Stopped.

IDL: ON

[Others]
ON: Line pressure up.
OFF: No action (normal operation)

-

OK

CHECK AND REPLACE ECM(See page 

01-31

)

NG

C93266

E1

E2

SLT-

SLT+

C82157

C91564

SLT+

SLT-

-

DIAGNOSTICS

ELECTRONIC CONTROLLED AUTOMATIC
TRANSAXLE [ECT]

05-445

598

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

2

INSPECT TRANSMISSION WIRE(SLT)

(a)

Disconnect the transmission wire connector (E2) from the
transaxle.

(c)

Measure the resistance between the terminals SLT+ and
SLT-.
OK:
Resistance: 5.0 - 5.6 

Ω 

at 20 

°

C (68

°

F)

NG

Go to step 4

OK

3

CHECK HARNESS AND CONNECTOR(TRANSMISSION WIRE - ECM)

(a)

Connect the transmission wire connector to the transaxle.

(b)

Disconnect the ECM connector.

(c)

Measure the resistance between terminals SLT+ and
SLT-  of ECM connector.
OK:
Resistance: 5.0 - 5.6 

Ω

 at 20 

°

C (68 

°

F)

NG

REPAIR OR REPLACE HARNESS OR
CONNECTOR(See page 

01-31

)

OK

CHECK AND REPLACE ECM(See page 

01-31

)

D25466

1

2

1

2

(+)

(-)

05-446

-

DIAGNOSTICS

ELECTRONIC CONTROLLED AUTOMATIC
TRANSAXLE [ECT]

599

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

4

INSPECT LINE PRESSURE CONTROL SOLENOID ASSY(SLT)

(a)

Remove the line pressure control solenoid (SLT).

(b)

Measure the resistance between terminals.
OK:
Resistance: 5.0 - 5.6 

Ω

 at 20

°

C (68

°

F)

(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 LINE PRESSURE CONTROL
SOLENOID ASSY(SLT)

OK

REPAIR OR REPLACE TRANSMISSION WIRE(See page 

01-31

)