ignition LEXUS SC400 1991 Service Owners 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

6. TILT UP REMINDER SYSTEMIf the ignition switch is turned from ON to OFF or ACC and the sliding roof rem\
ains tilted up, after 60 seconds
have elapsed or either the driver or passenger door is opened, a buzzer will\
sound for approx. 8 seconds
as a reminder that the sliding roof is tilted up.
Parts Location
±
BODY ELECTRICAL SYSTEM Sliding Roof SystemBE±177
WhereEverybodyKnowsYourName

(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
WhereEverybodyKnowsYourName

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
WhereEverybodyKnowsYourName

INSPECTION OF MIRROR ECU
1. INSPECT MIRROR ECU CIRCUITDisconnect the connectors from the ECU and inspect the
connector on the wire harness side as shown in the chart be-
low.
Check forTester connectionConditionSpecified value
ContinuityA1±A2ConstantContinuity
A1±A3ConstantContinuity
A8±A10ConstantContinuity
A9±A10ConstantContinuity
A11±GroundConstantContinuity
A12±A13ConstantContinuity
A16±*ConstantContinuity
B1±B2Right mirror switch on DOWNContinuity
B1±B4Right mirror switch to RIGHTContinuity
B1±B5Left mirror switch to RIGHTContinuity
B1±B6Left mirror switch to DOWNContinuity
B2±B3Right mirror switch to UPContinuity
B3±B4Right mirror switch to LEFTContinuity
B3±B5Left mirror switch to LEFTContinuity
B3±B6Left mirror switch to UPContinuity
VoltageA4±GroundConstantBattery positive voltage
A7±GroundIgnition switch to ACCBattery positive voltageA7±GroundIgnition switch to OFFNo voltage
*: Terminal 1/18 of the Tilt and Telescopic ECU
If circuit is not as specified, inspect the wire harness and mir-
ror switch or motor assembly.
BE±188
±
BODY ELECTRICAL SYSTEM Power Mirror Control System
WhereEverybodyKnowsYourName

(Circuit)
Disconnect the control panel connector and inspect the con-
nector on wire harness side as shown.
Check forTester connectionConditionSpecified value
Voltage2±GroundLight control switch positionTAIL or HEADBattery voltage
OFFNo voltage
If circuit is not as specified, refer to BE±199, 201, 203 wiring
diagrams and inspect the circuits connected to other parts.
(Radio Receiver Assembly)
REMOVAL AND INSTALLATION OF
RADIO RECEIVER ASSEMBLY
(See page BE±112)
INSPECTION OF RADIO RECEIVER
ASSEMBLY
INSPECT RADIO RECEIVER ASSEMBLY
(Circuit)
Disconnect the connectors from the radio receiver assembly.
And inspect the connector on the wire harness side as
shown.
(without CD player)
Check forTester connectionConditionSpecified value
ContinuityA7±GroundConstantContinuity
VoltageA4±GroundConstantBattery voltage
VoltageA3±GroundIgnition switch positionACC or ONBattery voltageg
LOCKNo voltage
A10±GroundLight control switch positionTAIL or HEADBattery voltageg
OFFNo voltage
If circuit is not as specified, refer to BE±199 wiring diagrams
and inspect the circuits connected to other parts.
±
BODY ELECTRICAL SYSTEM Audio SystemBE±207
WhereEverybodyKnowsYourName

(With CD player)
Check forTester connectionConditionSpecified value
VoltageA4±GroundConstantBattery voltage
A3±GroundIgnition switch positionACC or ONBattery voltageg
LOCKNo voltage
A2±GroundLight control switchTAIL or HEADBattery voltageg
positionOFFNo voltage
If circuit is not as specified, refer to BE±201, 203 wiring dia-
grams and inspect the circuits connected to other parts.
HINT: Check the wire harness between radio receiver assem-
bly and the CD auto changer, between radio receiver assem-
bly and power amplifier, in accordance with the wiring dia-
grams in BE±201, 203.
(Front Door Speaker)
REMOVAL AND INSTALLATION OF
FRONT DOOR SPEAKER
(See page BO±35)
(Tweeter)
REMOVAL AND INSTALLATION OF
TWEETER
(See page BO±34)
(Rear Speaker)
REMOVAL AND INSTALLATION OF
REAR SPEAKER
1. REMOVE REAR SPEAKER
(a) Remove the package tray trim.
HINT: (See page BO±124)
(b) Remove eight bolts.
(c) Disconnect connectors and remove the rear speaker.
2. INSTALL REAR SPEAKER For installation, follow the removal procedure in reverse.
BE±208
±
BODY ELECTRICAL SYSTEM Audio System
WhereEverybodyKnowsYourName

(c) Disconnect the connector and remove the wooferamplifier.
2. INSTALL WOOFER AMPLIFIER For installation, follow the removal procedure in reverse.
INSPECTION OF WOOFER AMPLIFIER
INSPECT WOOFER AMPLIFIER
(Circuit)
Disconnect the connector from woofer amplifier and inspect
the connector on the wire harness side as shown.
Check forTester connectionConditionSpecified value
Continuity7±GroundConstantContinuity
Voltage3±GroundConstantBattery voltage
4±GroundIgnition switch positionACC or ONBattery voltage
6±Ground
g
LOCKNo voltage
If circuit is not as specified, refer to BE±201 wiring diagrams
and inspect the circuits connected to other parts.
(Power Amplifier)
REMOVAL AND INSTALLATION OF
POWER AMPLIFIER
(Pioneer)
1. REMOVE POWER AMPLIFIER (a) Remove the RH side cover.
(b) Remove the CD auto changer (See page BE±212).
(c) Disconnect two connectors and remove three nuts and the power amplifier with the bracket.
(d) Remove four bolts and the power amplifier.
2. INSTALL POWER AMPLIFIER For installation, follow the removal procedure in reverse.
BE±210
±
BODY ELECTRICAL SYSTEM Audio System
WhereEverybodyKnowsYourName

(Nakamichi)
1. REMOVE POWER AMPLIFIER
(a) Remove the RH side cover.
(b) Remove the CD auto changer (See page BE±212).
(c) Disconnect three connectors and remove three nuts and the power amplifier with the bracket.
(d) Remove four bolts and the power amplifier.
2. INSTALL WOOFER AMPLIFIER For installation follow the removal procedure in reverse.
POWER AMPLIFIER INSPECTION
INSPECT POWER AMPLIFIER
(Circuit)
Disconnect the connector from power amplifier and inspect
the connector on the wire harness side as shown.
(Produced by PIONEER)
 Check for Tester connection Condition Specified value
 Continuity B7±Ground Constant Continuity
 Voltage B10±Ground Constant Battery positive voltage
  A14±Ground
A6 G d
 Ignition switch position ACC or ON Battery positive voltage  A6±Ground  LOCK No voltage
If circuit is not as specified, refer to BE±201 wiring diagrams
and inspect the circuits connected to other parts.
±
BODY ELECTRICAL SYSTEM AUDIO SYSTEMBE±211
WhereEverybodyKnowsYourName

(Produced by NAKAMICHI)
 Check for Tester connection Condition Specified value 

Continuity 

B7±Ground
C7±Ground 


Constant


Continuity
 

Voltage 

B10±Ground
C3±Ground 


Constant


Battery positive voltage
 


 

A6±Ground
A14±Ground 


Ignition switchposition
 


ACC or ON

Battery positive voltage
 


 


C4±Ground
C6±Ground 


Ignition switch position 


LOCK

No voltage
If circuit is not as specified, refer to
BE±203 wiring diagrams
and inspect the circuits connected to other parts.
CD AUTO CHANGER
CD AUTO CHANGER REMOVAL AND
INSTALLATION
1. REMOVE CD AUTO CHANGER (a) Remove RH side cover.
(b) Disconnect two connectors.
(c) Remove three bolts, one nut and the CD auto changer.
CD AUTO CHANGER INSPECTION
INSPECT CD AUTO CHANGER(Circuit)
Disconnect connectors from CD auto changer and inspect
the connector on the wire harness side as shown.
BE±212
±
BODY ELECTRICAL SYSTEM AUDIO SYSTEM
WhereEverybodyKnowsYourName