Lexus SC300 / Lexus SC400. Service manual - part 227

6. REMOVE 

CLOCK

Remove the two screws and the clock.

7. 

REMOVE FUEL AND TEMPERATURE GAUGE
Release the four lugs, and separate the two gauges from the
meter lens.

ASSEMBLY OF COMBINATION METER
ASSEMBLY

For installation, follow the removal procedure in reverse.

INSPECTION OF COMBINATION METER
ASSEMBLY

1. 

INSPECT COMBINATION METER WIRING CIRCUIT
Disconnect connector A, connector B and connector C from
the combination meter and inspect the connectors on the
wire harness side as follows.

BE–106

–

BODY ELECTRICAL SYSTEM

Combination Meter

Connection

Check for

Tester connection

Condition

Specified value

A19 A15

Trip switch A/B

Push

Continuity

Trip switch

Continuity

A19–A15

Trip switch A/B

Free

No continuity

Trip switch

Continuity

A20 A15

Trip switch RESET

Push

Continuity

A20–A15

Trip switch RESET

Free

No continuity

DOME
Fuse

Voltage

A11–Ground

Constant

Battery positive voltage

Speed
S

Voltage

A13 A15

Ignition
switch

*

3

 Revolve propeller shaft

0V 

 11V

Sensor

Voltage

A13–A15

switch 
ON

*

3

 Stop propeller shaft

0V or 11V

C1–Ground

P

Battery positive voltage

C2–Ground

Ignition

R

Battery positive voltage

Neutral  start

it h

Voltage

C3–Ground

Ignition
switch 
ON and

N

Battery positive voltage

switch

Voltage

C4–Ground

ON and
shift lever

D

Battery positive voltage

C5–Ground

shift lever
position

2

Battery positive voltage

C16–Ground

osition

L

Battery positive voltage

O/D OFF

Continuity

C18 Ground

O/D OFF switch

ON

Continuity

Switch

Continuity

C18–Ground

O/D OFF switch

OFF

No continuity

Alternator

Continuity

C15–Ground

Engine stop

Continuity

”L” terminal

Voltage

C14–Ground

Engine running

Battery positive voltage

Fuel

Continuity

A7 Ground

Fuel remainder

Full

No continuity

Sender

Continuity

A7–Ground

Fuel remainder

Empty

Continuity

Gauge

Full, Approx. 79.3 mm
(3.12 in.)

Approx. 6 

Resistance

A8–C8

Float 
position

1/2, Approx. 193.1 mm
(76.0 in.)

Approx. 32.5 

Empty, Approx. 308.1 mm
(12.13 in.)

Approx. 97 

*Window
washer level

Continuity

B9–Ground

ON (float down)

Continuity

washer level
warning
switch

Continuity

B9 Ground

(Canada)

OFF (float up)

No continuity

Brake fluid

Brake fluid level

ON (float down)

Continuity

Level warning

Brake fluid level
warning SW

OFF (float up)

No continuity

SW and
Parking brake
SW

Continuity

C13–Ground

Parking brake

ON (Depress the Ped-
al))

Continuity

SW

Parking brake
SW

OFF (Release the Ped-
al)

No continuity

Low oil
Pressure

Continuity

C19 Ground

Engine condition

Running

No continuity

Pressure
Warning SW

Continuity

C19–Ground

Engine condition

Stop

Continuity

Door courtesy

Continuity

C12 Ground

Driver’s and

Open (ON)

Continuity

y

Switch

Continuity

C12–Ground

Driver s and
passenger’s door

Closed (OFF)

No continuity

IGN fuse

Voltage

C14 Ground

Ignition switch

ON

Battery positive voltage

Voltage

C14–Ground

Ignition switch

LOCK or ACC

No voltage

CIG fuse

Voltage

A6 Ground

Ignition switch

ACC or ON

Battery positive voltage

Voltage

A6–Ground

Ignition switch

LOCK or START

No voltage

BE–107

–

BODY ELECTRICAL SYSTEM

Combination Meter

Connection

Check for

Tester connection

Condition

Specified value

Turn signal

Hazard warning switch ON

Battery positive

Turn signal
SW and

B 16 Ground

Hazard warning switch ON

Battery  ositive
voltage 

↔

 0V

Hazard

B–16–Ground

IG SW ON and turn signal SW ”Left”

Battery positive

Warning
S i h

Voltage

IG SW ON and turn signal SW ”Left”

Battery  ositive
voltage 

↔

 0V

Switch

Voltage

Hazard warning switch ON

Battery positive

B 17 Ground

Hazard warning switch ON

Battery  ositive
voltage 

↔

 0V

B–17–Ground

IG SW ON and turn signal SW ”Right”

Battery positive

IG SW ON and turn signal SW ”Right”

Battery  ositive
voltage 

↔

 0V

Headlight

Li ht

t l SW

Dimmer SW ”HI” or

Battery positive

Headlight

Voltage

B7–Ground

Light control SW
”HEAD”

Dimmer SW  HI  or
”Flash”

Battery  ositive
voltage

Voltage

B7–Ground

”HEAD”

Dimmer SW ”LO”

No voltage

Continuity

B6–Ground

Light control SW
”HEAD”

Dimmer SW ”HI” or
”Flash”

Continuity

Continuity

B6 Ground

”HEAD”

Dimmer SW ”LO”

No continuity

Igniter

Voltage

A9–Ground

Engine Running

Voltage
fluctuates

ECT pattern

Voltage

B4 Ground

IG SW ON and ECT pattern

PWR

Battery positive voltage

ECT  attern
Select switch

Voltage

B4–Ground

IG SW ON and ECT  attern
select SW position

NORM No voltage

Engine oil

Oil temperature below approx. 55

°

C (131

°

F)

Continuity

g

Level warn-
ing Switch

Continuity

B8–Ground

Oil temperature
above approx. 55

°

C

ON (float up)

Continuity

g

Continuity

B8 Ground

above a

rox. 55 C

(131

°

F) and SW

position

OFF (float off)

No continuity

GAUGE fuse

Voltage

A1 Ground

Ignition switch

ON

Battery positive voltage

Voltage

A1–Ground

Ignition switch
position

LOCK, ACC, START

No voltage

Neutral Start

Voltage

A12–Ground

Ignition switch
position

START (”P” or ”N”
range)

Battery positive voltage

switch

Voltage

A12 Ground

position

LOCK, ACC, ON

No voltage

ECU–B

Voltage

C11 Ground

Ignition switch

ON

Battery positive voltage

Fuse

Voltage

C11–Ground

Ignition switch
position

LOCK, ACC, START

No voltage

Rheostat
Li ht

t l

ON (Rheostat knob
t

d

iti

B tt

lt

Light control
Volume

Light control SW

turned any position
except fully clock-

Battery voltage or
5V or more

Volume

Voltage

A2–Ground

g

HEAD or TAIL and
rheostat volume

except fully clock-
wise)

5V or more

Voltage

A2 Ground

rheostat volume
knob position

OFF (Rheostat knob)
turned fully clock

No voltage

knob  osition

turned fully clock-
wise)

No voltage

Ground

A8–Ground

Constant

Continuity

Continuity

A10–Ground

Constant

Continuity

Continuity

A22–Ground

Constant

Continuity

A23–Ground

Constant

Continuity

*1

 Jack up the vehicle.

*2

 Shift lever position is ”P” range.

If circuit is not as specified, refer to 

BE–100

 wiring diagrams

and inspect the circuits connected to other parts.

BE–108

–

BODY ELECTRICAL SYSTEM

Combination Meter

(Odometer and Twin Trip Switch)

REMOVAL AND INSTALLATION OF
ODOMETER AND TWIN TRIP SWITCH

(See page 

BE–103

)

INSPECTION OF ODOMETER AND TWIN
TRIP SWITCH

INSPECT ODOMETER AND TWIN TRIP SWITCH

(Continuity)
Inspect continuity between terminals.

If continuity is not as specified, replace the odometer and twin
trip switch.

(Speedometer)

INSPECTION OF SPEEDOMETER

INSPECT SPEEDOMETER (ON–VEHICLE)

Using a speedometer tester, inspect the speedometer for al-
lowable indication error and check the operation of the odom-
eter.
HINT: Tire wear and tire over or under inflation will increase
the indication error.
If error is excessive, replace the speedometer.

–

BODY ELECTRICAL SYSTEM

Combination Meter

BE–109