Lexus SC300 / Lexus SC400. Manual - part 620

INSPECTION OF WATER TEMPERATURE
SENSOR

1. 

REMOVE LOWER HIGH–TENSION CORD COVER
(See steps 1, 2 and 5 to 12 on pages 

FI–27

 to 29)

2. 

REMOVE RH IGNITION COIL
(a)  Disconnect the ignition coil connector.
(b)  Remove the two bolts, and disconnect the ignition coil.

(c)  Disconnect the cam position sensor connector from the

ignition coil bracket, and remove the ignition coil.

3. DISCONNECT 

HOSES

Disconnect the following hoses:

(1)  Upper radiator hose from front water by–pass joint
(2)  Lower radiator hose from water inlet
(3)  Radiator reservoir hose from front water inlet hous-

ing

4. 

REMOVE WATER INLET AND INLET HOUSING
(a)  Disconnect the water by–pass hose from the water inlet

housing.

(b)  Remove the two bolts holding the water inlet housing to

the water pump.

(c)  Pull out the water inlet and inlet housing assembly.
(d)  Remove the O–ring from the water inlet housing.

5. REMOVE 

WATER 

TEMPERATURE 

SENSOR

(a)  Disconnect the water temperature sensor connector.
(b)  Remove the water temperature sensor and gasket.

FI–99

EFI SYSTEM   –   Electronic Control System (Water Temperature Sensor)

6. INSPECT 

WATER 

TEMPERATURE 

SENSOR

Using an ohmmeter, measure the resistance between the ter-
minals.

Resistance: Refer to the chart graph

If the resistance is not as specified, replace the sensor.

7. REINSTALL 

WATER 

TEMPERATURE 

SENSOR

(a)  Install a new gasket to the water temperature sensor.
(b)  Install the water temperature sensor.

Torque: 20 N

⋅

m (200 kgf

⋅

cm, 14 ft

⋅

lbf)

(c)  Connect the water temperature sensor connector.

8. 

REINSTALL WATER INLET AND INLET HOUSING
(a)  Remove any old packing (FIPG) material and be careful

not to drop any oil on the contact surfaces of the water
inlet housing and water pump.

•

Using a razor blade and gasket scraper, remove all
the old packing (FIPG) material from the gasket
surfaces and sealing groove.

•

Thoroughly clean all components to remove all the
loose material.

•

Using a non–residue solvent, clean both sealing
surfaces.

(b)  Apply seal packing to the sealing groove of the water

inlet housing as shown in the illustration.

Seal packing: Part No. 08826–00100 or equivalent

•

Install a nozzle that has been cut to a 2–3 mm
(0.08–0.12 in.) opening.

HINT: Avoid applying an excessive amount to the surface.

•

Parts must be assembled within 5 minutes of
application. Otherwise the material must be
removed and reapplied.

•

Immediately remove nozzle from the tube and
reinstall cap.

(c)  Install a new O–ring to the water inlet housing.
(d)  Apply soapy water to the O–ring.

FI–100

EFI SYSTEM   –   Electronic Control System (Water Temperature Sensor)

(e)  Push in the water inlet housing end into the water pump

hole.

(f)  Install the water inlet and inlet housing assembly with

the two bolts. Alternately tighten the bolts.

Torque: 18 N

⋅

m (185 kgf

⋅

cm, 13 ft

⋅

lbf)

(g)  Connect the water by–pass hose to the water inlet

housing.

9. RECONNECT 

HOSES

Connect the following hoses:

(1)  Upper radiator hose to front water by–pass joint
(2)  Lower radiator hose to water inlet
(3)  Radiator reservoir hose to front water inlet housing

10. REINSTALL 

RH 

IGNITION 

COIL

(a)  Install the ignition coil with the two bolts.

(b)  Install the cam position sensor connector to the ignition

coil bracket.

(c)  Connect the ignition coil connector.

11.  REINSTALL LOWER HIGH–TENSION CORD COVER

(See steps 1 to 13 and 16 to 18 on pages 

FI–39

 to 41)

FI–101

EFI SYSTEM   –   Electronic Control System (Water Temperature Sensor)

EGR Gas Temperature Sensor (USA Spec. only)

COMPONENTS FOR REMOVAL AND INSTALLATION

FI–102

                             –   Electronic Control System (EGR Gas Temperature Sensor (USA Spec. only))

EFI SYSTEM