Lexus ES300 (1997 year). Manual - part 336

A00381

ON

E2(–)

VC(+)

S05696

BE6653

–

DIAGNOSTICS

ENGINE

DI–121

273

1997 LEXUS ES300   (RM511U)

4

Check voltage between terminals VC and E2 of ECM connector.

PREPARATION:
(a)

Remove the glove compartment (See page 

SF–65

).

(b)

Turn ignition switch ON.

CHECK:
Measure voltage between terminals VC and E2 of ECM con-
nector.
OK:
Voltage:  4.5 

∼

 5.5 V

NG

 Check and replace ECM (See page

IN–27

).

OK

Check for open and short in harness and
connector between ECM and EGR valve
position sensor (VC line).

DI–122

–

DIAGNOSTICS

ENGINE

274

1997 LEXUS ES300   (RM511U)

DTC

P1411

EGR Valve Position Sensor Circuit 
Range/Performance Problem

CIRCUIT DESCRIPTION

Refer to DTC P1410 (EGR Valve Position Sensor Circuit Malfunction) on page 

DI–118

.

DTC No.

DTC Detecting Condition

Trouble Area

P1411

Conditions (a) and (b) continue for 7 sec. or more:

(2 trip detection logic)

(a) Engine Coolant Temp. < 55

°

C (131

°

F)

(b) EGLS 

 1.65 V or EGLS < 0.35 V

EGR valve position sensor

INSPECTION PROCEDURE

1

Are there any other codes (besides DTC P1411) being output?

YES

 Go to relevant DTC chart.

NO

Replace EGR valve position sensor.

DI0A3–01

A00953

Fusible

Link

Block

FL
MAIN

Battery

Stop Light Switch

B–R

B–G

AL

T

1B

1C

F11

F6

STOP

4

7

G–W

W

2

1

1R

1R

1S

4

5

2

G–W

Light
Failure
Sensor

7

2

To Stop Light

G–W

G–W

J27 Junction
Connector

1

E7

24

ECM

STP

E1

Instrument Panel J/B

Instrument Panel J/B

1

–

DIAGNOSTICS

ENGINE

DI–123

275

1997 LEXUS ES300   (RM511U)

DTC

P1520

Stop Light Switch Signal Malfunction

CIRCUIT DESCRIPTION

This signal is used to detect when the brakes have been applied. The STP signal voltage is the same as
the voltage supplied to the stop lights.
The STP signal is used mainly to control the fuel cut–off engine speed (The fuel cut–off engine speed is re-
duced slightly when the vehicle is braking.).

DTC No.

DTC Detecting Condition

Trouble Area

P1520

The stop light switch does not turn off even once the vehicle is

driven

(2 trip detection logic)

Short in stop light switch signal circuit

Stop light switch

ECM

WIRING DIAGRAM

INSPECTION PROCEDURE

DI0A4–01

A00240

ON

ON

STP(+)

Brake Pedal
Depressed

Brake Pedal
Released

BE6653
Q06993
BE6653
S04161

DI–124

–

DIAGNOSTICS

ENGINE

276

1997 LEXUS ES300   (RM511U)

1

Check operation of stop light.

CHECK:
Check if the stop lights go on and off normally when the brake
pedal is operated and released.

NG

Check and repair stop light circuit.

OK

2

Check STP signal.

When using LEXUS hand–held tester:
PREPARATION:
(a)

Connect the LEXUS hand–held tester to the DLC3.

(b)

Turn ignition switch ON and LEXUS hand–held tester
main switch ON.

CHECK:
Read the STP signal on the LEXUS hand–held tester.
OK:

Brake pedal is depressed: STP......ON
Brake pedal is released:    STP......OFF

When not using LEXUS hand–held tester:
PREPARATION:
Turn ignition switch ON.
CHECK:
Check voltage between terminal STP of ECM and body ground.
OK:

Brake pedal

Voltage

Depressed

7.5 

∼

 14 V

Released

Below 1.5 V

OK

Check for intermittent problems
(See page 

DI–3

).

NG