Lexus ES300 (1997 year). Manual — part 324

S06906

Vehicle Speed

70

∼

90 km/h

(43

∼

56 mph)

Idling

IG SW OFF

(1)

(2)

(3)

(4)

(5)

(6)

Warmed up

3

∼

5 min.

3 min.

3

∼

5 min.

2 min.

Time

S06906

–

DIAGNOSTICS

ENGINE

DI–73

225

1997 LEXUS ES300 (RM511U)

SYSTEM CHECK DRIVING PATTERN

(1) Connect the OBD II scan tool or LEXUS hand–held tester to the DLC3.
(2) Start and warm up the engine with all accessories switched OFF.
(3) Run the vehicle at 70

∼

90 km/h (43

∼

56 mph) for 3 min. or more.

(4) Idle the engine for about 2 min.
(5) Start the engine and do steps (3) and (4) again.
(6) Check the READINESS TESTS mode on the OBD II scan tool or LEXUS hand–held tester.
If COMPL is displayed and the MIL does not light up, the system is normal.
If INCMPL is displayed and the MIL does not light up, run the vehicle step (5) for some times and check
it.
HINT:INCMPL is displayed when either condition (a) or (b) exists.
(a)

The system check is incomplete.

(b)

There is a malfunction in the system.
If there is a malfunction in the system, the MIL light up after steps (2) to (5) above are done again.

A00305

ON

ON

EGR Gas Temp.
Sensor

EGR Gas Temp.
Sensor

ECM

ECM

5V

5V

E2

E2

14

22

14

22

1

2

1

2

THG

THG

E8

E9

E8

E9

BE6653
FI7055
BE6653
FI7054

DI–74

–

DIAGNOSTICS

ENGINE

226

1997 LEXUS ES300 (RM511U)

INSPECTION PROCEDURE

LEXUS hand–held tester

1

Connect LEXUS hand–held tester and read value of EGR gas temperature.

PREPARATION:
(a)

Connect the LEXUS hand–held tester to the DLC3.

(b)

Warm up the engine.

CHECK:
Read EGR gas temperature on LEXUS hand–held tester during idling.
OK:
EGR gas temp. : 10

°

C (50

°

F)

∼

150

°

C (302

°

F) (Not immediately after driving)

HINT:If there is an open circuit, LEXUS hand–held tester indicates 3.1

°

C (37.6

°

F).

If there is an short circuit, LEXUS hand–held tester indicates 159.3

°

C (318.7

°

F).

OK

Go to step 4.

NG

2

Check for open or short in harness or ECM.

For open circuit
PREPARATION:
(a)

Disconnect the EGR gas temp. sensor connector.

(b)

Connect sensor wire harness terminals together.

(c)

Turn ignition switch ON.

CHECK:
Read EGR gas temperature on the LEXUS hand–held tester.
OK:
EGR gas temp. : 159.3

°

C (318.7

°

F)

For short circuit
PREPARATION:
Disconnect the EGR gas temp. sensor connector.
CHECK:
Read EGR gas temperature on the LEXUS hand–held tester.
OK:
EGR gas temp. : 3.1

°

C (37.6

°

F)

OK

Confirm good connection at sensor.
If OK, check and replace EGR gas temp. sensor.

NG

A00224

ON

ECM

EGR Gas Temp. Sensor

1

2

5V

THG

E2

14

22

E8

E9

E2

THG

BE6653
FI7057
P23869

A00225

ON

EGR Gas temp. Sensor

ECM

E8

BE6653
FI7099
FI7105

–

DIAGNOSTICS

ENGINE

DI–75

227

1997 LEXUS ES300 (RM511U)

3

Check for open or short in harness or ECM.

For open circuit
PREPARATION:
(a)

Remove the glove compartment (See page

SF–64

).

(b)

Connect between terminals THG and E2 of ECM connec-
tors.

HINT:EGR gas temp. sensor connector is disconnected. Before
checking, do a visual check and contact pressure check for the
ECM connector (See page

IN–27

).

CHECK:
Read EGR gas temperature on the LEXUS hand–held tester.
OK:
EGR gas temp. : 159.3

°

C (318.7

°

F)

For short circuit
PREPARATION:
(a)

Remove the glove compartment (See page

SF–64

).

(b)

Disconnect the E8 connector of ECM.

CHECK:
Read EGR gas temperature on the LEXUS hand–held tester.
OK:
EGR gas temp. : 3.1

°

C (37.6

°

F)

OK

Repair or replace harness.

NG

Confirm connection at ECM.
If OK, check and replace ECM.

4

Check connection and blockage of vacuum hose (See page

EC–7

).

NG

Repair or replace vacuum hose.

OK

A00473

A00473

ON

Air

E

G

Air

E

G

F

F

E

VSV is ON

VSV is OFF

DI–76

–

DIAGNOSTICS

ENGINE

228

1997 LEXUS ES300 (RM511U)

5

Check VSV for EGR.

PREPARATION:
Select the ACTIVE TEST mode on the LEXUS hand–held
tester.
CHECK:
Check operation VSV when it is operated by the LEXUS
hand–held tester.
OK:

VSV is ON:
Air from pipe E is flowing out through pipe F.
VSV is OFF:
Air from pipe E is flowing out through pipe G.

OK

Go to step 7.

NG

6

Check operation of VSV for EGR (See page

SF–50

).

NG

Replace VSV for EGR.

OK

Check for open in harness and connector
between engine room J/B and ECM.