ECU LEXUS SC400 1991 Service Manual PDF

POWER WINDOW CONTROL
SYSTEM
Description
The Power Window System raises and lowers the window glass in each door usi\
ng electrical power. The compo-
nent parts of this system and their functions are described in the following\
table.
Parts NameFunction
Theft Deterrent and
Door Lock
Control ECUCurrent is sent to the power window main relay only when the ignition sw\
itch
is on or within a specified period after the ignition switch is turned o\
ff.
Power Window
Main RelayCurrent from the theft deterrent and door lock control ECU to the power
window main relay switches large current from the master switch ON and O\
FF.
Master SwitchThis switch turns current to each power window motor ON and OFF and
switches it. It also includes a circuit for ºOne Touch Power Windowº use of
the driver's window and a built±in window lock switch which controls the
operation of all power window switches.
Power Window
SwitchThis switch is installed on each door except on the driver's door. It is supplied
with current from the master siwtch and turns the current to the motor O\
N and
OFF and switches the current. This switch will not operate when the wind\
ow
lock switch inside the master switch is in the LOCK position.
Power Window
MotorThis motor moves the window regulator directly when current is supplied \
to it
from the master switch or power window switch. The motor has a built±\
in
circuit breaker.
Parts Location
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BODY ELECTRICAL SYSTEM Power Window Control SystemBE±147
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(Circuit)
(a) Disconnect the connector from the motor.
(b) Connect the connector to the master switch and powerwindow switch.
(c) Inspect the c onnector on the wire harness side as
shown.
Check forTester connectionConditionSpecified value
Voltage1±GroundIgnition switch ON andDOWNBattery positive voltagegIgnition switch ON and
master switch positionUP or OFFNo voltage
*Ignition switch ON andDOWNBatterypositive voltage* Ignition switch ON and
power window switch
DOWNBattery ositive voltage
power window switch
iti
UP or OFFNo voltagepositionUP or OFFNo voltage
2±GroundIgnition switch ON andUPBattery positive voltageIgnition switch ON and
master switch positionDOWN or OFFNo voltage
*Ignition switch ON andUPBatterypositive voltage* Ignition switch ON and
power window switch
UPBattery ositive voltage
power window switch
iti
DOWN or OFFNo voltagepositionDOWN or OFFNo voltage
*: Set the window lock switch to the unlock position.
If the circuit is not as specified, refer to BE±148 wiring dia-
gram and inspect the circuits connected to other parts.
(Theft Deterrent and Door Lock Control
ECU)
REMOVAL AND INSTALLATION OF
THEFT DETERRENT AND DOOR LOCK
CONTROL ECU
1. REMOVE THEFT DETERRENT AND DOOR LOCK CONTROL ECU
(a) Remove following parts.(See page BO±112 and 113)
w Instrument No. 1 Under Cover.
w Instrument No. 1 lower finish panel.
(b) Disconnect the connector and remove the ECU
2. INSTALL THEFT DETERRENT AND DOOR LOCK CONTROL ECU
For installation, follow the removal procedure in reverse.
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INSPECTION OF THEFT DETERRENT
AND DOOR LOCK CONTROL ECU
INSPECT THEFT DETERRENT AND DOOR LOCK CONTROL
ECU(Circuit)
(a) Inspect ECU Power Source Circuit.(See page BE±376)
(b) Inspect Actuator Power Source Circuit.
(See page BE±378)
(c) Inspect Ignition Switch Circuit. (See page BE±25)
(d) Inspect Door Open Detection Switch Circuit.
(See page BE±392)
If circuit is as specified, inspect ECU operation.
(Operation)
(a) With the connectors connected, shut all doors.
(b) Check that there is 10 V ~ 14 V between terminal B8 and
ground when the ignition switch is turned on.
(c) After turning the ignition switch off, check within 60 seconds that there is battery voltage between terminal
B8 and ground.
(d) Turn the ignition switch on then off, and check that there
is 10 V ~ 14 V between terminal B8 and ground when the
ignition is switched off.
(e) Open the front door within 60 seconds of turning the
ignition off and check that there is no voltage between
terminal B8 and ground.
(f) Close all the doors and turn the ignition switch on.
(g) When a front door is opened, check that there is battery voltage between terminal B8 and ground.
(h) Check that there is no voltage between terminal B8 and ground when the ignition switch is turned to off.
If operation is not as specified, replace the ECU.
BE±156
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BODY ELECTRICAL SYSTEM Power Window Control System
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Troubleshooting
You will find the cause of trouble more easily by properly using the table \
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 the part.
See page
BE±4 ,21BE±4,21BE±4,20BE±4,20BE±156BE±152BE±149BE±151BE±152BE±26BE±392BE±4,20 ±±
Part
name
Trouble
AM1 FuseDOME FuseDOOR FusePOWER FuseTheft Deterrent and Door Lock Control ECUPower Window Main RelayPower Window Master SwitchPower Window SwitchPower Window MotorIgnition SwitchDoor Open Detection SwitchECU±IG FuseWire Harness
*1 Power window does not operate.1234
*2 Power window does not operate.35467218
ªOne Touch Power Window Systemº does
not operate.1
Only one window glass does not move.1234
ªWindow Lock Systemº does not operate1
ªWindow Lock Illuminationº does not light
up.1
Key±off power window does not operate124536
*1: Dook Lock does not operate.
*2: Dook Lock is normal.
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BODY ELECTRICAL SYSTEM Power Window Control SystemBE±157
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(Sliding Roof Limit Switch)
REMOVAL AND INSTALLATION OF LIMIT
SWITCH
(See Sliding Roof on page BO±85)
INSPECTION OF LIMIT SWITCH
1. INSPECT LIMIT SWITCH CIRCUIT
Terminal
Switch position
OFF (SW pin released)
OFF (SW pin released) ON (SW pin pushed in)
ON (SW pin pushed in)
No. 1 limit
switch
No. 2 limit
switch
If continuity is not as specified, replace the switch.
2. INSPECT MOTOR WIRE CIRCUIT (a) Check that there is continuity between terminals A1 andB3.
(b) Check that there is continuity between terminals A2 and B4.
(c) Check that there is continuity between terminals A3 and B1.
If continuity is not as specified, replace the switch.
(Theft Deterrent and Door Lock Control
ECU)
(See page BE±155)
(Door Courtesy Switch)
(See page BE±79)
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BODY ELECTRICAL SYSTEM Sliding Roof SystemBE±181
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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
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POWER MIRROR CONTROL
SYSTEM
Description
The Power Miror Control System carries out mirror left/right and up/down ad\
justments electrically when the Mir-
ror Switch is operated. In addition, operation of the Driving Position M\
emory and Return Switches makes it pos-
sible to store the adjusted position in memory and reproduce each adjustment \
when desired. The component
parts of this system and their functions are described in the following table\
.
Parts NameFunction
Outside Rear View
Mirror ECUThe Outside Rear View Mirror ECU is supplied with power from the DOME and RADIO
NO.2 fuses and is connected to the Tilt and Telescopic ECU, Mirror Switch, each
mirror motor and ground.
Rear View Adjustment
SwitchOperation of this switch sends left/right, up/down signals to Outside Re\
ar View Mirror
ECU.
Driving Position Memory
and Return SwitchesMemory and return signals are sent to the ECU via the Tilt and Telescopic ECU.
Mirror MotorThese motors operate on current from the Outside Rear View Mirror ECU, moving
the various parts of the mirror directly.
These sensors send signals about the motor positions to the ECU for stor\
ing in memory
and during return operation.
Left/Right Select SwitchThis switch is used to select operation of the Rear View Adjustment Switch for the
leftor right hand side mirror.
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BODY ELECTRICAL SYSTEM Power Mirror Control SystemBE±183
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2. INSPECT MIRROR POSITION SENSORSHINT: Strip off the vinyl tape of the connector and remove ter-
minals 1, 2, 3, 5 and 9 from the connector housing.
(a) Connect a series of three 1.5 volt dry cell batteries.
(b) Connect the positive (+) lead from the dry cell batteriesto terminal 5 and the negative (±) lead to terminal 9.
(c) Connect the positive (+) lead from the voltmeter to
terminal 6 and the negative (±) lead to terminal 9.
(d) Apply battery voltage to terminals 2 and 3, check that the voltage gradually changes according to the table
below while the mirror moves between the uppermost
position and lowermost position.
Mirror
positionLowermostUppermost
Voltage2.8 ± 5.0Changes
gradually0 ± 0.9
If voltage value is not as specified, replace the motor assem-
bly.
(e) Disconnect the four leads of the battery and voltmeter.
(f) Connect the positive (+) lead from the voltmeter to terminal 4 and the negative (±) lead to terminal 9.
(g) Apply battery voltage to terminals 1 and 2n inspect that the voltage gradually changes according to the table
below while the mirror moves between the leftmost
position and rightmost position.
Mirror
PositionLeftmostRightmost
Voltage
Left
Mirror2.8 ± 5.0Changes
gradually0 ± 0.9
VoltageRight
Mirror0 ± 0.9Changes
gradually2.8 ± 5.0
If voltage value is not as specified, replace the motor assem-
bly.
(Mirror ECU)
REMOVAL AND INSTALLATION OF
MIRROR ECU
REMOVAL AND INSTALL MIRROR ECU (a) Remove the No. 1 under cover .(See page BO±112)
(b) Re mo ve th e two scre ws an d disc onnect the two
connectors and then pull out the ECU.
(c) For installation, follow the removal procedure in reverse.
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BODY ELECTRICAL SYSTEM Power Mirror Control SystemBE±187
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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
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2. INSPECT MIRROR ECU OPERATIONConnect the connectors and using a voltmeter with high im-
pedance (10 k
/V minimum), measure the voltage at each
terminal and body ground.
Check forTester connectionConditionSpecified value
VoltageA1±GroundRight mirror switch to LEFTBattery positive voltage
A2±GroundRight mirror switch to UPBattery positive voltage
A3±GroundRight mirror switch to RIGHT or DOWNBattery positive voltage
*A5±GroundRight mirror to leftmost position0±0.9 V*A5±GroundRight mirror to rightmost position2.8±5.0 V
*A6±GroundRight mirror to lowermost position2.8±5.0 V*A6±GroundRight mirror to uppermost position0±0.9 V
A8±GroundLeft mirror switch to RIGHTBattery positive voltage
A9±GroundLeft mirror switch to UPBattery positive voltage
A10±GroundLeft mirror switch to LEFT or DOWNBattery positive voltage
A13±GroundRight or left mirror switch to any position except
OFFApprox. 5 V
*A14±GroundLeft mirror to leftmost position2.8±5.0 V*A14±GroundLeft mirror to rightmost position0±0.9 V
*A15±GroundLeft mirror to lowermost position2.8±5.0 V*A15±GroundLeft mirror to uppermost position0±0.9 V
B2±GroundConstantApprox. 5 V
B4±GroundConstantApprox. 5 V
B5±GroundConstantApprox. 5 V
B6±GroundConstantApprox. 5 V
*: Confirm that the voltage changes gradually while the mirror moves
If operation is not as specified, inspect the wire harness and
mirror switch or motor assembly. Then if these are correct, re-
place the ECU.
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BODY ELECTRICAL SYSTEM Power Mirror Control SystemBE±189
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