Lexus SC300 / Lexus SC400. Manual - part 331

4. 

REMOVE OIL COOLER
Remove the three bolts and oil cooler.

INSPECTION OF OIL COOLER

INSPECT OIL COOLER
Check the oil cooler for damage or clogging.
If necessary, replace the oil cooler.

INSTALLATION OF OIL COOLER

(See Components on page 

CO–58

)

1. 

INSTALL OIL COOLER
Install the oil cooler with the three bolts.

Torque: 18 N

⋅

m (180 kgf

⋅

cm, 13 ft

⋅

lbf)

2. 

CONNECT HOSES FROM OIL COOLER
Connect the following hoses:

(1)  Inlet hose (from reservoir tank)
(2)  Outlet hose (from hydraulic motor)

3. 

INSTALL PS OIL COOLER
Install the oil cooler with the two bolts.

4. 

REMOVE FENDER LINER

5. 

FILL COOLING FAN RESERVOIR TANK WITH FLUID
(See pages 

CO–23

 and 24)

6. 

START ENGINE AND CHECK FOR LEAKS

–

COOLIING SYSTEM

Electronically Controlled Hydraulic 
Cooling Fan (Oil Cooler)

CO–59

Electronic Control Parts

(System Circuit)

(Cooling Fan ECU)
COMPONENTS FOR REMOVAL AND
INSTALLATION

CO–60

–

COOLIING SYSTEM

Electronically Controlled Hydraulic Cooling Fan
(Electronic Control Parts)

INSPECTION OF COOLING FAN ECU

1. 

DISCONNECT CABLE FROM NEGATIVE TERMINAL OF
BATTERY
CAUTION: Work must be started after 20 seconds or longer
from the time the ignition switch is turned to the ”LOCK” posi-
tion and the negative (–) terminal cable is disconnected from
the battery.

2. 

DISCONNECT COOLING FAN ECU CONNECTOR
(See Components on page 

CO–60

)

(a)  Remove the instrument panel under cover.
(b)  Remove the lower instrument panel finish panel and

glove compartment door assembly.

(c)  Disconnect the cooling fan ECU connector.

3. 

INSPECT COOLING FAN ECU
(a)  Connect the cable to the negative (–) terminal of the

battery.

(b)  Check the connector on the wiring harness side as

shown in the chart.

Check for

Tester connection

Condition

Specified value

Voltage

1–Ground

Ignition switch ON

Battery voltage

Resistance

2–3

Solenoid valve at cold (20

°

C (68

°

F))

7.5–8.5 

Continuity

4–Ground

–

Continuity

Continuity

5–Ground

Throttle valve open

No continuity

Continuity

5–Ground

Throttle valve closed

Continuity

Resistance

9–10

Coolant temp. at 80

°

C (176

°

F)

1.48–1.58 k

(c)  Disconnect the cable from the negative (–) terminal of

the battery.

4. 

RECONNECT COOLING FAN ECU CONNECTOR

5.  RECONNECT CABLE TO NEGATIVE TERMINAL OF

BATTERY

–

COOLIING SYSTEM

Electronically Controlled Hydraulic
Cooling Fan (Electronic Control Parts)

CO–61

 (Water Temperature Sensor)

COMPONENTS FOR REMOVAL AND
INSTALLATION

INSPECTION OF WATER TEMPERATURE
SENSOR

1. 

DISCONNECT CABLE FROM NEGATIVE TERMINAL OF
BATTERY
CAUTION: Work must be started after 20 seconds or
longer from the time the ignition switch is turned to the
”LOCK” position and the negative (–) terminal cable is
disconnected from the battery.

2. 

REMOVE ENGINE UNDER COVER

3. 

DRAIN ENGINE COOLANT (See page 

CO–6

)

4. REMOVE 

WATER 

TEMPERATURE 

SENSOR

(a)  Disconnect the water temperature sensor connector.
(b)  Remove the water temperature sensor from left side of

the radiator lower tank.

(c)  Remove the O–ring from the water temperature sensor.

CO–62

–

COOLIING SYSTEM

Electronically Controlled Hydraulic
Cooling Fan (Electronic Control Parts)