Lexus ES300 (2002 year). Manual - part 329

C82158

C91565

DSL

E1

C90646

(+)

(-)

-

DIAGNOSTICS

ELECTRONIC CONTROLLED AUTOMATIC
TRANSAXLE [ECT]

05-435

588

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

3

CHECK HARNESS AND CONNECTOR(TRANSMISSION WIRE - ECM)

(a)

Connect the transmission wire connector.

(b)

Disconnect the ECM connector.

(c)

Measure the resistance between terminals DSL and E1.
OK:
Resistance: 11 - 13

 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

)

4

INSPECT SHIFT SOLENOID VALVE DSL

(a)

Remove the shift solenoid valve DSL.

(b)

Measure the resistance between the terminal DSL of shift
solenoid valve and the solenoid body.
OK:
Resistance: 11 - 13 

Ω

 at 20 



C (68 



F)

(c)

Connect positive (+) lead to the terminal of solenoid con-
nector, negative (-) lead to the solenoid body.
OK:
The solenoid valve makes an operationing noise.

NG

REPLACE SHIFT SOLENOID VALVE DSL

OK

REPAIR OR REPLACE TRANSMISSION WIRE(See page 

01-31

)

05-436

-

DIAGNOSTICS

ELECTRONIC CONTROLLED AUTOMATIC
TRANSAXLE [ECT]

589

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

DTC

P1520

STOP LIGHT SWITCH MALFUNCTION

CIRCUIT DESCRIPTION

The purpose of this circuit is to prevent the engine from stalling while driving in lock-up condition, when
brakes are suddenly applied.
When the brake pedal is depressed, this switch sends a signals to the ECM. Then the ECM cancels the op-
eration of the lock-up clutch while braking is in progress.

DTC No.

DTC Detection Condition

Trouble Area

P1520

No stop light switch signal to ECM during driving
(2 trip detection logic)

Open or short in stop light switch circuit

Stop lamp switch assy

ECM

WIRING DIAGRAM

See page 

05-159

.

INSPECTION PROCEDURE

1

READ VALUE OF 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 ”STOP LIGHT SW” in the DATALIST and read its value displayed 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

Measurement Item/

Display (Range)

Normal Condition

Diagnostic Note

STOP LIGHT SW

Stop light SW Status/

ON or OFF

Brake Pedal is depressed: ON

Brake Pedal is released: OFF

←

OK

REPAIR OR REPLACE ECM(See page 

01-31

)

NG

2

INSPECT STOP LAMP SWITCH ASSY

(See page 

05-268

 or 

05-359

)

NG

REPLACE STOP LAMP SWITCH ASSY

OK

0527S-04

-

DIAGNOSTICS

ELECTRONIC CONTROLLED AUTOMATIC
TRANSAXLE [ECT]

05-437

590

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

3

CHECK HARNESS AND CONNECTOR(STOP LAMP SWITCH ASSY - ECM)

NG

REPAIR OR REPLACE HARNESS OR
CONNECTOR(See page 

01-31

)

OK

REPAIR OR REPLACE ECM(See page 

01-31

)

C93634

ECM

NT+

NT-

27

35

L

LG

2

1

E9

E9

T4 
Turbine Speed Sensor

05-438

-

DIAGNOSTICS

ELECTRONIC CONTROLLED AUTOMATIC
TRANSAXLE [ECT]

591

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

DTC

P1725

NT REVOLUTION SENSOR CIRCUIT
MALFUNCTION

CIRCUIT DESCRIPTION

This sensor detects the rotation speed of the input turbine. By comparing the input turbine speed signal (NT)
with the counter gear speed sensor signal (NC), the ECM detects the shift timing of the gears and appropri-
ately controls the engine torque and hydraulic pressure according to various conditions. Thus smooth gear
shifting is performed.

DTC No.

DTC Detection Condition

Trouble Area

P1725

ECM detects conditions (a), (b), (c) and (d) continuity for 5 sec.
or more: (1 trip detection logic)

(a) Vehicle speed: 50 km/h (20 mph) or more

(b) Solenoid valves and park/neutral position switch are normal

(c) NT < 300 rpm

Open or short in turbine speed sensor circuit

Speed sensor (NT)

ECM

WIRING DIAGRAM

0527T-04