Lexus GS300/400 (2000 year). Service manual - part 123

B02035

ECT Switch
Connector

ECT
Switch

O–Ring

CO0AJ–01

P05962

Ohmmeter

–

COOLING (2JZ–GE)

ENGINE COOLANT TEMPERATURE (ECT) SWITCH

CO–31

1569

ENGINE COOLANT
TEMPERATURE (ECT) SWITCH

INSPECTION

1.

DRAIN ENGINE COOLANT

2.

REMOVE ECT SWITCH

(a)

Disconnect the connector.

(b)

Remove the ECT switch.

(c)

Remove the O–ring from the ECT switch.

3.

INSPECT ECT SWITCH

(a)

Using an ohmmeter, check that there is no continuity be-
tween the terminals when the coolant temperature is
above 93

°

C (199

°

F).

If there is continuity, replace the switch.
(b)

Using an ohmmeter, check that there is continuity be-
tween the terminals when the coolant temperature is be-
low 83

°

C (181

°

F).

If there is no continuity, replace the switch.
4.

REINSTALL ECT SWITCH

(a)

Install a new O–ring to the ECT switch.

(b)

Install the ECT switch.

(c)

Connect the connector.

5.

REFILL WITH ENGINE COOLANT

6.

START ENGINE AND CHECK FOR COOLANT LEAKS

B01376

Radiator
Fan Main
Relay

CO0AK–01

B00019

Ohmmeter

Continuity

Ohmmeter

Ohmmeter

No Continuity

Continuity

2

1

5

4

3

B00020

Ohmmeter

Ohmmeter

No Continuity

Continuity

2

1

5

4

3

Battery

CO–32

–

COOLING (2JZ–GE)

RADIATOR FAN MAIN RELAY

1570

RADIATOR FAN MAIN RELAY

INSPECTION

1.

REMOVE RELAY BOX COVER

2.

REMOVE RADIATOR FAN MAIN RELAY (Marking:
RAD FAN MAIN)

3.

INSPECT RADIATOR FAN MAIN RELAY

(a)

Inspect the relay continuity.
(1)

Using an ohmmeter, check that there is continuity
between terminals 3 and 5.

If there is no continuity, replace the relay.

(2)

Check that there is continuity between terminals 2
and 4.

If there is no continuity, replace the relay.

(3)

Check that there is no continuity between terminals
1 and 2.

If there is continuity, replace the relay.

(b)

Inspect the relay operation.
(1)

Apply battery positive voltage across terminals 3
and 5.

(2)

Using an ohmmeter, check that there is no continu-
ity between terminals 2 and 4.

If there is continuity, replace the relay.

(3)

Check that there is continuity between terminals 1
and 2.

If there is no continuity, replace the relay.
4.

REINSTALL RADIATOR FAN MAIN RELAY

5.

REINSTALL RELAY BOX COVER

B00924

No.1 Cooling
Fan Relay

CO0AL–01

B00021

Ohmmeter

Continuity

Ohmmeter

Continuity

4

1

3

2

B00022

No Continuity

Ohmmeter

4

1

3

2

Battery

B01373

No.2 Cooling
Fan Relay

A00970

Continuity

Ohmmeter

No Continuity

Continuity

4

1

3

2

Ohmmeter

5

Ohmmeter

–

COOLING (2JZ–GE)

COOLING FAN RELAY

CO–33

1571

COOLING FAN RELAY

INSPECTION

1.

INSPECT NO.1 COOLING FAN RELAY

(a)

Remove the relay box cover.

(b)

Remove the No.1 cooling fan relay. (Marking: FAN NO.1)

(c)

Inspect the No.1 cooling fan relay continuity.
(1)

Using an ohmmeter, check that there is continuity
between terminals 1 and 2.

If there is no continuity, replace the relay.

(2)

Check that there is continuity between terminals 3
and 4.

If there is no continuity, replace the relay.

(d)

Inspect the No.1 cooling fan relay operation.
(1)

Apply battery positive voltage across terminals 1
and 2.

(2)

Using an ohmmeter, check that there is no continu-
ity between terminals 3 and 4.

If there is continuity, replace the relay.
(e)

Reinstall the No.1 cooling fan relay.

(f)

Reinstall the relay box cover.

2.

INSPECT NO.2 COOLING FAN RELAY

(a)

Remove the relay box cover.

(b)

Remove the No.2 cooling fan relay. (Marking: FAN NO.2)

(c)

Inspect the No.2 cooling fan relay continuity.
(1)

Using an ohmmeter, check that there is continuity
between terminals 1 and 2.

If there is no continuity, replace the relay.

(2)

Check that there is continuity between terminals 3
and 4.

If there is no continuity, replace the relay.

(3)

Check that there is no continuity between terminals
3 and 5.

If there is continuity, replace the relay.

A00971

Ohmmeter

No Continuity

Ohmmeter

Continuity

4

1

3

2

5

Battery

B01375

No.3 Cooling
Fan Relay

A00968

No Continuity

Continuity

1

2

Ohmmeter

5

Ohmmeter

3

A00969

Ohmmeter

Continuity

1

3

2

5

Battery

CO–34

–

COOLING (2JZ–GE)

COOLING FAN RELAY

1572

(d)

Inspect the No.2 cooling fan relay operation.
(1)

Apply battery positive voltage across terminals 1
and 2.

(2)

Using an ohmmeter, check that there is no continu-
ity between terminals 3 and 4.

If there is continuity, replace the relay.

(3)

Using an ohmmeter, check that there is continuity
between terminals 3 and 5.

If there is no continuity, replace the relay.
(e)

Reinstall the No.2 cooling fan relay.

(f)

Reinstall the relay box cover.

3.

INSPECT NO.3 COOLING FAN RELAY

(a)

Remove the relay box cover.

(b)

Remove the No.3 cooling fan relay. (Marking: FAN NO.3)

(c)

Inspect the No.3 cooling fan relay continuity.
(1)

Using an ohmmeter, check that there is continuity
between terminals 1 and 2.

If there is no continuity, replace the relay.

(2)

Check that there is no continuity between terminals
3 and 5.

If there is  continuity, replace the relay.

(d)

Inspect the No.3 cooling fan relay operation.
(1)

Apply battery positive voltage across terminals 1
and 2.

(2)

Using an ohmmeter, check that there is  continuity
between terminals 3 and 5.

If there is no continuity, replace the relay.
(e)

Reinstall the No.3 cooling fan relay.

(f)

Reinstall the relay box cover.