relay LEXUS SC300 1991 Service Owner's Manual

SLIDING ROOF SYSTEM
Description
Standby Operation

Current flows from the DOME fuse to terminal A1 of the sliding roof control rel\
ay (hereafter called
relay).

When the ignition switch is ON, the current flows from the power window relay to terminal A3 of the
relay.
Operation
Roof Position
Function Fully
Open Fully
Closed
Momentary
Stop
Limit
Switch
No. 1
Limit
Switch
No. 2
Sliding
Roof
Control
Switch Down
Up
Sliding Period Idling Period
CLOSE DOWN OPEN
UP ON
ON OFF
OFF
Tilting
Period
2. OPEN operation
When the switch on the ºOPENº side of the control switch is pushed, co\
ntinuity is produced between termi-
nal A8 of the relay and body ground. Then the relay operates, the curren\
t flows through terminal A3 of the
relay
terminal B3
terminal 1 of the sliding roof motor
terminal 3
terminal B1 of the relay
terminal
A5
the body ground, and the motor starts to run in order to open the slidi\
ng roof.
3. CLOSE operation
When the switch on the ºCLOSEº side of the control switch is pushed, c\
ontinuity is produced between termi-
nal A7 of the relay and body ground. Then the relay operates, the current f\
lows through terminal A3 of the
relay
terminal B1
terminal 3 of the sliding roof motor
terminal 1
terminal B3 of the relay
terminal
A5
the body ground, and the motor starts to run in order to close the slid\
ing roof.
Momentary Stop
When the sliding roof reaches about 200 mm (7.87 in.) short of the fully closed position, the limit \
switch
is turned from ON to OFF, so there is not continuity between terminal B1 of the relay and body g\
round No.
1. As a result, the sliding roof stops at that position.
4. TILT UP operation
When the switch on the ºUPº side of the control switch is pushed, cont\
inuity is produced between terminal
A6 of the relay and body ground. Then the relay operates, the current flow\
s through terminal A3 of the relay

terminal B1
terminal 3 of the sliding roof motor
terminal 1
terminal B3 of the relay
terminal
A5
the body ground, and the motor starts to run in order to tilt up the sl\
iding roof.
5. TILT DOWN operation When the switch on the ºDOWNº side of the control switch is pushed, co\
ntinuity is produced between termi-
nal A2 of the relay and body ground. Then the relay operates, the current f\
lows through terminal A3 of the
relay
terminal B3
terminal 1 of the sliding roof motor
terminal 3
terminal B1 of the relay
terminal
A5
the body ground, and the motor starts to run in order to tilt down the \
sliding roof.
BE±176
±
BODY ELECTRICAL SYSTEM Sliding Roof System
WhereEverybodyKnowsYourName

Parts Inspection
(Power Window Main Relay)
INSPECTION OF POWER WINDOW MAIN
RELAY
(See Power Window Main Relay on page BE±152)
(Sliding Roof Switch)
REMOVAL AND INSTALLATION OF
SLIDING ROOF SWITCH
(See Sliding Roof on page BO±85)
INSPECTION OF SLIDING ROOF SWITCH
INSPECT SWITCH CONTINUITY
Terminal
Switch position
SLIDE
TILT OFF
OPEN
CLOSE
OFFUP
DOWN
If continuity is not as specified, replace the switch.
(Sliding Roof Motor)
REMOVAL AND INSTALLATION OF
MOTOR
(See Sliding Roof on page
BO±85)
INSPECTION OF MOTOR
INSPECT MOTOR OPERATION
(a) Disconnect the connector which has 3 terminals andinspect on the clamped connector side.
(b) Connect the positive (+) lead from the battery to terminal
1 and negative (±) lead to terminal 3 and check that the
motor turns clockwise.
(c) Connect the positive (+) lead from the battery to terminal
3 and negative (±) lead to terminal 1 and check that the
motor turns counterclockwise.
If operation is not as specified, replace the motor.
(d) Connect the connector.
±
BODY ELECTRICAL SYSTEM Sliding Roof SysytemBE±179
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(Sliding Roof Control Relay)
REMOVAL AND INSTALLATION OF
SLIDING ROOF CONTROL RELAY
(See Sliding Roof on page BO±85)
INSPECTION OF SLIDING ROOF
CONTROL RELAY
INSPECT CONTROL RELAY CIRCUIT
Disconnect the connector from the relay and inspect the con-
nector on the wire harness side as shown in the chart.
Check forTest connectionConditionSpecified value
ContinuityA2 ± GroundSliding roof control OFF or UPNo continuityyg
switch position (TILT)DOWNContinuity
A6 ± GroundSliding roof control OFF or DOWNNo continuityg
switch position (TILT)UPContinuity
A7 ± GroundSliding roof control OFF or OPENNo continuityg
switch position (SLIDE)CLOSEContinuity
A8 ± GroundSliding roof control OFF or CLOSENo continuityg
switch position (SLIDE)OPENContinuity
B1 ± GroundConstantNo continuity
B1 ± B3ConstantContinuity
B2 ± GroundNo. 1 limit switch
p
osition
OFF (Sliding roof tilt up or
approx. 200 mm (7.87 in.)
opened)No continuity
positionON (Except for conditions
mentioned above)Continuity
B3 ± GroundConstantNo continuity
B4 ± GroundConstantContinuity
B5 ± GroundConstantContinuity
B6 ± GroundNo. 2 limit switch OFF (Sliding roof closed)No continuity
positionON (Sliding roof opened)Continuity
VoltageA1 ± GroundConstantBattery voltageg
A3 ± GroundIgnition switch positionLOCK or ACC ( * )No voltageg
ONBattery voltage
(*) Except within 60 seconds after turning the ignition key to the OFF\
position and both the driver's door and
the passenger's door are closed. If circuit is as specified, replace the relay.
BE±180
±
BODY ELECTRICAL SYSTEM Sliding Roof System
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Troubleshooting
You will find the cause of trouble more easily by properly using the tabl\
e shown below. In this table, the numbers
indicate the order of priority of the causes of trouble. Check each part in the \
order shown. If necessary, replace
the part.
See page
BE±4,21BE±4,21BE±4,20BE±4,20BE±156BE±152BE±180BE±179BE±179 ±±BE±181BE±26BE±79BE±4,20 ±±
Part
name
Trouble
AM1 FuseDOME FuseDOOR FusePOWER FuseTheft Deterrent and Door Lock Control ECUPower Window Main RelaySliding Roof Control RelaySliding Roof SwitchSliding Roof MotorSliding Rood Motor (Stones to foreign material
trapped in motor assembly)Limit SwitchIgnition SwitchDoor Courtesy SwitchECU±IG FuseWire Harness
*1 Sliding roof system does not operate.1234
*2 Sliding roof system does not operate.35467892110
Sliding roof system operates abnormally.1324
Sliding roof system stops operation half way.1342
Buzzer does not sound.123
Buzzer sounds abnormally.1
ªKey±off Sliding Roofº operation does not
operate.124536
*1: Door Lock does not operate
*2: Door Lock is normal
BE±182
±
BODY ELECTRICAL SYSTEM Sliding Roof System
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2. INSPECT ANTENNA MOTOR
(a) Install antenna nut.
(b) Disconnect connector from the motor antenna control relay.
(c) Connect the positive (+) lead from the battery to terminal 2and the negative (±) lead to terminal 5 on the wire harness
side connector.
(d) Check that the motor turns (moves upward).
NOTICE: These tests must be performed quickly (within 4±8
seconds) to prevent the coil from burning out.
(e) Then, reverse the polarity, check that the motor turns the opposite way (moves downward).
NOTICE: These tests must be performed quickly (within 4±8
seconds) to prevent the coil from burning out.
HINT: When the motor is normal, lower the antenna to the
lower most position.
If operation is not as specified, replace the antenna motor as-
sembly.
GLASS PRINTED ANTENNA
GLASS PRINTED ANTENNA
INSPECTION
1. INSPECT GLASS PRINTED ANTENNA(Use same procedure as for ºINSPECT DEFOGGER
WIRESº on page BE±173.)
2. REPAIR GLASS PRINTED ANTENNA (Use same procedure as for ºREPAIR DEFOGGER WIRESº
on page BE±174.)
BE±216
±
BODY ELECTRICAL SYSTEM AUDIO SYSTEM
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32AntennaANTENNA±RELATED
Does antenna extend when radio switched ON?Wire harness faulty.
Is there battery voltage between the following
terminals with connector disconnected?


Motor antenna control relay 6 ± ground

Motor antenna control relay 14 ± ground

Motor antenna control relay 3 ± ground
Wire harness faulty.Replace fuses.
Radio receiver assembly faulty.
Check if ECU±IG, RADIO No. 1 and RADIO No.
2 fuse are OK.
ªAMº button turned ON.
Is there battery voltage between the following
terminals with connector connected?

Radio receiver assembly A9 (*A1) ± ground

Radio receiver assembly A8 ± ground

Radio receiver assembly D4 ± ground

Radio receiver assembly D10 ± ground Radio receiver side
faulty.
Motor antenna faulty.
Temporarily install another motor antenna is
radio operating normally?
Glass printed antenna faulty.
Check if glass printed antenna is OK.
Is there continuity between the following terminals
with connector disconnected?

Motor antenna control relay 4 ± ground
Continued on next page.
BE±260±
BODY ELECTRICAL SYSTEM AUDIO SYSTEM
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Wire harness faulty.
Is there continuity between the following terminals
with connector disconnected?

Radio receiver assembly A9 (*A1) ± Motor anten-
na control relay 4

Radio receiver assembly A8 ± Motor antenna
control relay 5

Radio receiver assembly D4 ± Motor antenna
control relay 2

Radio receiver assembly D10 ± Motor antenna
control relay 12
Temporarily install another motor antenna con-
trol relay. Functions OK? Motor antenna control relay faulty.
Motor antenna control relay faulty.
±
BODY ELECTRICAL SYSTEM AUDIO SYSTEMBE±261
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HORN RELAY
HORN RELAY INSPECTION
INSPECT RELAY CONTINUITY AND OPERATION
If operation is not as specified, replace the relay.
Troubleshooting
You will find the cause of trouble more easily by properly using the tabl\
e shown below. In this table, the
numbers indicate the order of priority of the causes of trouble. Check each part in \
the order shown. If neces-
sary, replace these part.
See page
BE±4 , 21BE±264BE±263BE±263
±
Trouble
Parts
name
HAZ±HORN FuseHorn SwitchHorn SwitchHornWire Harness
\
\
Horn system does not operate 1 2 3 4 5\


\
Horns blow all the time
 


 

1
 

2
 


 

3
\


\
One horn operates but other horn does not
Operate 


 


 


 


1 


2
\
\
Horns operate abnormally  1  2 3
BE±264±
BODY ELECTRICAL SYSTEM HORN SYSTEM
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DESCRIPTION
The Power Seat Control System carries out seat slide, front vertical, rear \
vertical, reclining and lumbar support
position adjustments electrically. Power seat switch and lumbar support switch.
In addition, operation of the memory switch makes it possible to store the positions of the slide, front vertical,
rear vertical and reclining adjustments in memory and return to the posi\
tion.
The component parts of this system and their function are described in t\
he following table.
 Parts Name\
 \
Function
 








Driver's Seat ECU
\
 
\


\


\


\

\

The seat ECU controls power operation, memory operation, and position re\
turn
operation of the power seat. When input is received from the power seat \
switch,
the relay inside the ECU is controlled and the power seat operates. The \
seat
memory and position return are controlled by mutual communication betwee\
n the
electrically operated Tilt and Telescopic ECU and the seat ECU.
 

Power Seat Switch\
 
\

\

Operation of this switch sends slide, front vertical, rear vertical, rec\
lining signals
to ECU.
 




Driving Position
Memory and Return
Switch\
 
\


\

\

Memory and Return Signals are sent to the seat ECU via the Tilt and Telescopic
ECU.
 






Lumbar Support
Switch
\
 
\


\


\

\

This switch is supplied with power from the DOOR fuse. When the switch i\
s
operated, power is supplied to the lumbar support motor controlling the \
direction
in which the motor turns and turning the current ON and OFF. This switch is not
connected to the ECU and the adjustment position cannot be stored in mem\
ory
for return operation.
 

Position Sensor
\
 
\

\
This sensor sends signals on the position of each motor (slide, front v\
ertical, rear
vertical and reclining) to the ECU for use in memory and return.
 

*Motor
\
 
\

\

These motors operate on current from the driver's seat ECU moving the various
parts of the seat directly. Each motor has a built±in circuit breaker.
*: Slide, Front Vertical, Rear Vertical, Lumbar Support and Reclining.
Motors contained in each seat are described in the following table.
 Motor Slide Front
Vertical
 Rear
Vertical
 Reclining Lumbar
Support 

Seat 

Motor 


Vertical
Motor
 


Vertical
Motor
 


g
Motor 


Support
Motor
 Driver's Seat O* O* O* O* O
*: Operated by the memory and return functions. BE±266
±
BODY ELECTRICAL SYSTEM Power Seat Control System (Driver's Seat)
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Replacement of Fuse
HINT: If replacing the fuse, be sure to replace it with a fuse
with an equal amperage rating.
NOTICE:
1. Turn off all electrical components and the ignition switchbefore replacing a fuse. Do not exceed the fuse amperage
rating.
2. Always use a fuse puller for removing and inserting a fuse. Remove and insert straight in and out without
twisting. Twisting could force open the terminals too
much, resulting in a bad connection.
If a fuse continues to blow, a short circuit is indicated. The
system must be checked by a qualified technician.
HINT: The puller is located at Relay Block No. 2.
How to Inspect for System Inspection
This inspection precedure is a simple troubleshooting which
should be carried out on the vehicle during system operation
and is based on the assumption of system component
trouble (except for the wires and connectors, etc.).
Always inspect the trouble taking the following items into con-
sideration.
wGround point fault
w Open or short circuit of the wire harness
w Connector or terminal connection fault
w Fuse or fusible link fault
NOTICE:
1. This is an on±vehicle inspection during system
operation. Therefore, inspect the trouble with due regard
for safety.
2. If connecting the battery directly, be careful not to short circuit, and select the applicable voltage.
BE±4±
BODY ELECTRICAL SYSTEM General Information
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