Lexus SC300 / Lexus SC400. Manual - part 621

INSPECTION OF EGR GAS
TEMPERATURE SENSOR

1. 

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

2. 

DRAIN ENGINE COOLANT

3. 

REMOVE EGR VALVE
(a)  Disconnect the EGR gas temperature sensor.
(b)  Disconnect the following hoses from the EGR valve:

(1)  Water by–pass hose (from ISC valve)
(2)  Water by–pass hose (from rear water by–pass

joint)

(c)  Remove the two nuts, EGR valve and gasket.

4. 

REMOVE EGR VALVE ADAPTOR
(a)  Disconnect the EGR gas temperature sensor.
(b)  Disconnect the PCV hose from the EGR valve adaptor.

(c)  Remove the two bolts, two nuts, EGR valve adaptor and

gasket.

FI–103

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

5.  REMOVE EGR GAS TEMPERATURE SENSOR FROM

EGR VALVE ADAPTOR
(a)  Mount the EGR valve adaptor in a vise.
(b)  Remove the EGR valve adaptor.
(c) Remove 

the 

connector bracket from the sensor

connector.

6. 

INSPECT EGR GAS TEMPERATURE SENSOR
Using an ohmmeter, measure the resistance between the ter-
minals.

Resistance:

69–89 k

 at 50

°

C (112

°

F)

12–15 k

 at 100

°

C (212

°

F)

2–4 k

 at 150

°

C (302

°

F)

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

7. 

REINSTALL EGR GAS TEMPERATURE SENSOR TO EGR
VALVE ADAPTOR
(a)  Mount the EGR valve adaptor in a vise.
(b)  Install the EGR gas temperature to the adaptor.

Torque: 20 N

⋅

m (200 kgf

⋅

cm, 14 ft

⋅

lbf)

(c)  Install the connector bracket to the sensor connector.

8. 

REINSTALL EGR VALVE ADAPTOR
(a)  Install a new gasket, the adaptor and connector bracket

with the two bolts, two nuts, EGR valve adaptor and
gasket.

Torque: 18 N

⋅

m (185 kgf

⋅

cm, 13 ft

⋅

lbf)

NOTICE: Do not touch the air intake chamber and adap-
tor surfaces of the gasket with your hand.

(b)  Connect the PCV hose to the EGR valve adaptor.
(c)  Connect the EGR gas temperature sensor.

FI–104

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

9. REINSTALL 

EGR 

VALVE

(a)  Place a new gasket on the EGR valve adaptor.
NOTICE:

•

Do not touch the adaptor and EGR valve surfaces of the

gasket with your hand.

•

Align the port holes of the gasket and adaptor. Be careful

of the installation direction.

(b)  Install the EGR valve with the two nuts.

Torque: 18 N

⋅

m (185 kgf

⋅

cm, 13 ft

⋅

lbf)

(c)  Connect the following hoses to the EGR valve:

(1)  Water by–pass hose (from ISC valve)
(2)  Water by–pass hose (from rear water by–pass

joint)

(d)  Connect the EGR gas temperature sensor.

10.  RECONNECT CABLE FROM NEGATIVE TERMINAL OF

BATTERY

11.  REFILL WITH ENGINE COOLANT

FI–105

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

Knock Sensors

FI–106

                               –   Electronic Control System (Knock Sensors)

EFI SYSTEM