Lexus ES300 (1997 year). Manual — part 351

Q07936

NC2

–

NC2

+

Q08218

Magnet

–

DIAGNOSTICS

AUTOMATIC TRANSAXLE

DI–181

333

1997 LEXUS ES300 (RM511U)

INSPECTION PROCEDURE

1

Check resistance between terminals NC2

+

and NC2

–

of ECM.

PREPARATION:
Disconnect the connector from ECM.
CHECK:
Check resistance between terminals NC2

+

and NC2

–

of ECM.

OK:

Resistance: 560

∼

680

Ω

OK

Check and replace the ECM.

NG

2

Check No.2 vehicle speed sensor.

PREPARATION:
Remove the Direct clutch speed sensor from transaxle.
CHECK:
(a)

Measure resistance between terminals 1 and 2 of speed
sensor.

(b)

Check voltage between terminals 1 and 2 of the speed
sensor when a magnet is put close to the front end of the
speed sensor then taken away quickly.

OK:

(a) Resistance: 560

∼

680

Ω

(b) Voltage is generated intermittently.

HINT:The voltage generated is extremely low.

NG

Replace the Direct clutch speed sensor.

OK

Check and repair the harness and connector
between ECM and Direct clutch speed sen-
sor (See page

IN–27

).

AT5608

0

1

Electric Current (A)

High

Accumulator Control Pressure

D00060

(*) 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

D00062

1 msec./div.

5 V/div.

GND

Reference

Waveform between terminals SLN

+

and SLN

–

when engine is idling.

Waveform between terminals SLN

+

and SLN

–

when during shift change.

1 msec./div.

5 V/div.

GND

DI–182

–

DIAGNOSTICS

AUTOMATIC TRANSAXLE

334

1997 LEXUS ES300 (RM511U)

DTC

P1765

Linear Solenoid for Accumulator Pressure Control
Circuit Malfunction (Shift Solenoid Valve SLN)

CIRCUIT DESCRIPTION

The shift solenoid valve SLN controls the hydraulic pressure
acting on the accumulator control valve when gears are shifted
and performs smooth gear shifting.
The ECM determines optimum operating pressure according to
the signals from the throttle position sensor, vehicle speed sen-
sor and direct clutch speed sensor and controls the volume of
current flow to the solenoid valve.
The amount of current to the solenoid is controlled by the (*)
duty ratio of ECM output signals, causing a momentary change
to the hydraulic pressure acting on the clutches during gear
shifting.
When the duty ratio is high, the hydraulic pressure acting on the
clutches is low.

DTC No.

DTC Detecting Condition

Trouble Area

P1765

After the engine is warmed up, the current flow to the shift

solenoid valve SLN for 1 sec or more under condition (a) or

(b):

(a) Engine speed: 500 rpm or more

(b) Park/neutral position switch: ON (P or N position)

Open or short in shift solenoid valve SLN circuit

Shift solenoid valve SLN

ECM

DI0CY–01

D00037

Shift Solenoid
valve SLN

1

4

B–Y

W–L

3

2 SLN

–

SLN

+

ECM

E3

E3

E10

E9

D00050

2

1

2

1

–

DIAGNOSTICS

AUTOMATIC TRANSAXLE

DI–183

335

1997 LEXUS ES300 (RM511U)

WIRING DIAGRAM

INSPECTION PROCEDURE

1

Check shift solenoid valve SLN.

PREPARATION:
Disconnect the shift solenoid valve SLN connector.
CHECK:
(a)

Measure resistance between terminals 1 and 2 of sole-
noid connector.

(b)

Connect positive

lead with an 8

∼

10 W bulb to terminal

1 of solenoid connector and negative

lead to terminal

2, then check the movement of the valve.

OK:

(a) Resistance: 5.1

∼

5.5

Ω

(b)

When battery positive voltage is applied.

Valve move in direction in illustration.

(on the left)

When battery positive voltage is cut off.

Valve move in direction in illustration.

(on the right)

D00051

(+)

(–)

1 2

DI–184

–

DIAGNOSTICS

AUTOMATIC TRANSAXLE

336

1997 LEXUS ES300 (RM511U)

<Reference>
PREPARATION:
Connect positive

lead of the variable power supply to termi-

nal 1 of solenoid connector and negative

lead to terminal 2.

CHECK:
(a)

Check the movement of the valve when the voltage is
gradually increased.
(A current greater than 1A should not be supplied.)

(b)

Check the movement of the valve when the voltage is cut
off.

OK:

(a) As the voltage is increased, the valve should move
slowly in the

direction.

(b) The valve should return in the

direction.

NG

Replace the shift solenoid valve SLN.

OK

2

Check harness and connector between battery and shift solenoid valve SLN,
shift solenoid valve SLN and ECM (See page

IN–27

).

NG

Repair or replace the harness or connector.

OK

Check and replace the ECM.