Lexus SC300 / Lexus SC400. Manual - part 476

EFI Main Relay

INSPECTION OF EFI MAIN RELAY

1. REMOVE 

EFI MAIN RELAY FROM RELAY BOX IN ENGINE

COMPARTMENT

2. 

INSPECT EFI MAIN RELAY

A. Inspect relay continuity

(a)  Using an ohmmeter, check that there is continuity

between terminals 1 and 3.

(b)  Check that there is no continuity between terminals 2

and 4.

If continuity is not as specified, replace the relay.

B. Inspect relay operation

(a)  Apply battery voltage across terminals 1 and 3.
(b)  Using an ohmmeter, check that there is continuity

between terminals 2 and 4.

If operation is not as specified, replace the relay.

3. 

REINSTALL EFI MAIN RELAY

FI–64

–

EFI SYSTEM

Electronic Control System (EFI main RelaY)

VSV for EVAP

INSPECTION OF VSV FOR EVAP

(See Emission Control System on page 

EC–8

)

VSV for EGR

INSPECTION OF VSV FOR EGR

(See Emission Control Systems on page 

EC–13

)

VSV for ACIS

INSPECTION OF VSV FOR ACIS

(See page 

FI–60

)

–

EFI SYSTEM

Electronic Control System (VSV for EVAP)
(VSV for EGR) (VSV for ACIS)

FI–65

Throttle Body

FI–66

                                    –   Air Induction System (Throttle Body)

EFI SYSTEM

ON–VEHICLE INSPECTION

1. 

INSPECT THROTTLE BODY
(a)  Remove the throttle body cover.

•

Remove the mounting cap nut.

•

Loosen the two bolts, and remove the throttle body
cover.

(b)  Check that the throttle linkage moves smoothly.

(c)  Check the vacuum at each port.

•

Start the engine.

•

Check the vacuum with your finger.

Port name

At idling

At 3,000 rpm

P

No vacuum

Vacuum

*E

No vacuum

Vacuum

*R

No vacuum

Vacuum

* Exc. USA Spec.
(d)  Reinstall the throttle body cover.

3. 

INSPECT AND ADJUST DASH POT (DP)

A.  Warm up engine

Allow the engine to warm up to normal operating tempera-
ture.

B.  Check idle speed

Idle speed: 700 

±

 50 rpm

C.  Remove cap, filter and separator from DP

FI–67

EFI SYSTEM   –   Air Induction System (Throttle Body)