1991 LEXUS SC400 sensor

29
Position of Parts in Instrument Panel
H 7 Hazard SW S 10 Shift Lock ECUS 11 Step Light
I 14 Ignition Key Cylinder Light S 12 Stop Light SW
I 15 Ignition SW, Unlock Warning SW and Key Inter Lock Solenoid S 22 Short Connector
I 16 Integration Relay S 23 Short Connector S 24 Seat Heater SW (for M/T)
K 3 Kick Down SW T 6 TDCL (Total Diagnostic Communication Link)
L 1 Luggage Compartment Door Open SW T 7 Telescopic Position Sensor T 8 Theft Deterrent and Door Lock Control ECU
N 4 Noise Filter (for A/C System) T 9 Theft Deterrent and Door Lock Control ECU T 10 Tilt and Power Telescopic ECU
O 5 O/D Main SW T 11 Tilt and Power Telescopic ECU T 12 Traction Cut SW and Seat Heater SW (for A/T)
P 2 PPS ECU T 13 Traction ECU (for A/T)
P 3 Parking Brake SW T 14 Traction ECU (for A/T) T 15 Trip SW and Theft Deterrent Indicator Light
R 2 Radio and Player
R 3 Radio and Player W 6 Water Temp. Sensor (for A/C System)
R 4 Radio and Player (w/ CD Player) W 7 Wireless Door Lock Main SW
R 5 Radio and Player (w/o CD Player)
R 6 Radio and Player (w/o CD Player)
R 7 Remote Control Mirror ECU
R 8 Remote Control Mirror ECU
R 9 Rheostat
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30
ELECTRICAL WIRING ROUTING
Position of Parts in Body
A 30 ABS Speed Sensor Rear LH D 10 Door Lock Motor, Door Unlock Detection SW and
A 31 ABS Speed Sensor Rear RH Door Open Detection SW LH
A 32 Auto Antenna Motor and Relay D 11 Door Lock Motor, Door Unlock Detection SW andDoor Open Detection SW RH
C 20 CD Automatic Changer D 12 Driving Position Memory and Return SW
C 21 CD Automatic Changer
C 22 Choke Coil F 11 Front Door Speaker LH F 12 Front Door Speaker RH
D 4 DAY/NIGHT Shift SW F 14 Fuel Lid Opener Solenoid
D 5 Door Courtesy Light LH F 15 Fuel Pump
D 6 Door Courtesy Light RH F 16 Fuel Pump ECU
D 7 Door Key Lock and Unlock SW LH F 17 Fuel Sender
D 8 Door Key Lock and Unlock SW RH F 18 Fuel Sender
D 9 Door Lock Control SW RH H 8 High Mount Stop Light (w/o Rear Spoiler)
H 9 High Mount Stop Light (w/ Rear Spoiler)
L 2 Licence Plate Light
L 3 Light Failure Sensor
L 4 Luggage Compartment Door Opener Motor
L 5 Luggage Compartment Key Unlock SW
L 6 Luggage Compartment Light SW
L 7 Luggage Compartment Light
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31
Position of Parts in Body
M 1 Mobilephone R 16 Remote Control Mirror LH
M 2 Moon Roof Control Relay R 17 Remote Control Mirror RH
M 3 Moon Roof Control SW R 18 Remote Control Mirror SW
M 4 Moon Roof Motor and Limit SWS 13 Stereo Power Amplifier
O 8 Oxygen Sensor Sub (for California) S 14 Stereo Power Amplifier
P 4 Power Window Control SW RH T 16 Telephone Transceiver and Speaker Relay
P 5 Power Window Master SW and Door Lock Control SW LH T 17 Telephone Transceiver and Speaker Relay
P 6 Power Window Motor LH T 18 Tension Reducer Solenoid LH
P 7 Power Window Motor RH T 19 Tension Reducer Solenoid RH
P 20 Personal Light V 5 Vanity Light LH
R 10 Rear Combination Light LH V 6 Vanity Light RH
R 11 Rear Combination Light RH
R 12 Rear Speaker LH W 8 Wireless Door Lock ECU
R 13 Rear Speaker RH W 9 Woofer Speaker
R 14 Rear Window Defogger (+) W 10 Woofer Speaker Amplifier
R 15 Rear Window Defogger (±)
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32
ELECTRICAL WIRING ROUTING
Position of Parts in Seat
B 4 Buckle SW LH P 15 Power Seat Motor (for Driver's Seat Rear Vertical Control)
B 5 Buckle SW RH P 16 Power Seat Motor (for Driver's Seat Reclining Motor Control)P 17 Power Seat Motor (for Driver's Seat Slide Control)
F 19 Front Vertical Position Sensor P 18 Power Seat Motor (for Passenger's Seat Reclining Control) P 19 Power Seat Motor (for Passenger's Seat Slide Control)
P 8 Power Seat Control SW (for Driver's Seat)
P 9 Power Seat Control SW (for Passenger's Seat) R 19 Rear Vertical Position Sensor
P 10 Power Seat ECU (for Driver's Seat) R 20 Reclining Limit SW
P 11 Power Seat ECU (for Driver's Seat)
P 12 Power Seat ECU (for Passenger's Seat) S 15 Seat Heater (for Driver's Seat Back)
P 13 Power Seat Motor (for Driver's Seat Front Vertical Control) S 16 Seat Heater (for Driver's Seat Cushion)
P 14 Power Seat Motor (for Driver's Seat Lumbar S 17 Seat Heater (for Passenger's Seat Back) Support Control) S 18 Seat Heater (for Passenger's Seat Cushion) S 19 Slide Limit SW
S 20 Slide Position Sensor (for Driver's Seat)
S 21 Slide Position Sensor (for Passenger's Seat)
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150
CRUISE CONTROL
CURRENT IS APPLIED AT ALL TIMES THROUGH STOP FUSE TO TERMINAL 1 OF THE CONTROL ECU TERMINAL 2 OF STOP LIGHT
SWITCH, AND ALSO THROUGH THE DOME FUSE TO TERMINAL 15 OF CRUISE CONTROL ECU.
WITH THE IGNITION SWITCH TURNED TO ON, THE CURRENT FLOWS THROUGH GAUGE FUSE TO TERMINAL (A)1 OF COMBINATION
METER AND THE CURRENT THROUGH ECU±IG FUSE FLOWS TO TERMINAL 14 OF CRUISE CONTROL ECU.
WHEN THE IGNITION SWITCH IS ON AND THE CRUISE CONTROL MAIN SWITCH IS TUR\
NED ON, A SIGNAL IS INPUT FROM TERMINAL
15 OF CRUISE CONTROL MAIN SWITCH TO TERMINAL 4 OF CRUISE CONTROL ECU. AS A RESULT, THE CRUISE CONTROL ECU
FUNCTIONS AND THE CURRENT TO TERMINAL 14 OF CRUISE CONTROL ECU TO TERMINAL 13 OF CRUISE CONTROL ECU "
GROUND, AND THE CRUISE CONTROL SYSTEM IS IN A CONDITION READY FOR OPERATION.
AT THE SAME TIME, THE CURRENT THROUGH THE GAUGE FUSE FLOWS FROM TERMINAL (A)1 OF CRUISE CONTROL INDICATOR
LIGHT " TERMINAL (B)20 "TERMINAL 5 OF CRUISE CONTROL ECU "TERMINAL 13 " TO GROUND, CAUSING THE CRUISE
CONTROL INDICATOR LIGHT TO LIGHT UP, INDICATING THAT THE CRUISE CONTROL IS READY FOR OPERATION.
1. SET OPERATION
WHEN THE CRUISE CONTROL MAIN SWITCH IS TURNED ON AND THE SET SWITCH IS PUSHE\
D WITH THE VEHICLE SPEED WITHIN
THE SET LIMIT (APPROX. 40 KM/H, 2.5 MPH TO 200 KM/H, 124 MPH), A SIGNAL IS INPUT TO TERMINAL 18 OF THE CRUISE CONTROL
ECU AND THE VEHICLE SPEED AT THE TIME THE SET SWITCH IS RELEASED IS MEMORIZED IN THE ECU AS THE SET\
SPEED.
2. SET SPEED CONTROL
DURING CRUISE CONTROL DRIVING, THE ECU COMPARES THE SET SPEED MEMORIZED IN THE ECU WITH THE ACTUAL VEHICLE
SPEED INPUT INTO TERMINAL 20 OF THE CRUISE CONTROL ECU FROM THE SPEED SENSOR, AND CONTROLS THE CRUIS\
E
CONTROL ACTUATOR TO MAINTAIN THE SET SPEED.
WHEN THE ACTUAL SPEED IS LOWER THAN THE SET SPEED, THE ECU CAUSES THE CURREN\
T TO THE CRUISE CONTROL
ACTUATOR TO FLOW FROM TERMINAL 12 " TERMINAL 6 OF CRUISE CONTROL ACTUATOR "TERMINAL 7 " TERMINAL 11 OF
CRUISE CONTROL ECU. AS A RESULT, THE MOTOR IN THE CRUISE CONTROL ACTUATOR IS ROTATED TO OPEN THE THROTTLE
VALVE AND THE THROTTLE CABLE IS PULLED TO INCREASE THE VEHICLE SPEED. WHEN THE ACTUAL DRIVING SPEED IS HIGHER
THAN THE SET SPEED, THE CURRENT TO CRUISE CONTROL ACTUATOR FLOWS FROM TERMINAL 11 OF ECU "TERMINAL 7 OF
CRUISE CONTROL ACTUATOR "TERMINAL 6 "TERMINAL 12 OF CRUISE CONTROL ECU.
THIS CAUSES THE MOTOR IN THE CRUISE CONTROL ACTUATOR TO ROTATE TO CLOSE THE THROTTLE VALVE AND RETURN THE
THROTTLE CABLE TO DECREASE THE VEHICLE SPEED.
3. COAST CONTROL
DURING THE CRUISE CONTROL DRIVING, WHILE THE COAST SWITCH IS ON, THE CRUISE CONTROL ACTUATOR RETURNS THE
THROTTLE CABLE TO CLOSE THE THROTTLE VALVE AND DECREASE THE DRIVING SPEED. THE VEHICLE SPEED WHEN THE COAST
SWITCH IS TURNED OFF IS MEMORIZED AND THE VEHICLE CONTINUES AT THE NEW SET SPEED.
4. ACCEL CONTROL
DURING CRUISE CONTROL DRIVING, WHILE THE ACCEL SWITCH IS TURNED ON, THE CRUISE\
CONTROL ACTUATOR PULLS THE
THROTTLE CABLE TO OPEN THE THROTTLE VALVE AND INCREASE THE DRIVING SPEED.
THE VEHICLE SPEED WHEN THE ACCEL SWITCH IS TURNED OFF IS MEMORIZED AND THE \
VEHICLE CONTINUES AT THE NEW SET
SPEED.
5. RESUME CONTROL
UNLESS THE VEHICLE SPEED FALLS BELOW THE MINIMUM SPEED LIMIT (APPROX. 40 KM/H, 25 MPH) AFTER CANCELING THE SET
SPEED BY THE CANCEL SWITCH, PUSHING THE RESUME SWITCH WILL CAUSE THE VEHICLE \
TO RESUME THE SPEED SET BEFORE
CANCELLATION.
6. MANUAL CANCEL MECHANISM
IF ANY OF THE FOLLOWING OPERATIONS OCCURS DURING CRUISE CONTROL OPERATION, THE SAFETY MAGNETIC CLUTCH OF
THE ACTUATOR TURNS OFF AND THE MOTOR ROTATES TO CLOSE THE THROTTLE VALVE AND THE CRUISE CONTROL IS
RELEASED.
* PLACING THE SHIFT LEVER IN ªNº RANGE (NEUTRAL START SWITCH ON)). ªSIGNAL INPUT TO TERMINAL 2 OF ECUº
* DEPRESSING THE BRAKE LEVER (STOP LIGHT SWITCH ON). ªSIGNAL INPUT TO TERMINAL 16 OF ECUº
* PULLING THE PARKING BRAKE PEDAL (PARKING BRAKE SWITCH ON). ªSIGNAL INPUT TO TERMINAL 3 OF ECUº
* PUSHING THE CANCEL SWITCH (CANCEL SWITCH ON). ªSIGNAL INPUT TO TERMINAL 18ª
SYSTEM OUTLINE
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127
2 1
2
1
E18 E20
E20 I32
I32
B
27 B
4B 28 A20 B 29
B
42 B 63 B 41 B43 B64 B65 B 44 B 23 B3
ED
E18
L±R
Y±L
R±B
BR
L±R Y
R BR
BR
Y±L
R±B
L±R Y
R
BR
G
P
V
GR±Y LG
B±Y BR
LG
BR
W±B
BR L
LG
GR±Y
BR
L±R
GR±Y
14 8 13
3
NE
E11 VF2 TE1 VF1
VTA2 IDL2 VC VTA1 IDL1 E2 THW SP2 SP2±
G1 TVF1
E1
SUBTHROTTLEPOSITION
SENSOR
(
W/ TRACTION CONTROL ) THROTTLE POSITION SENSOR
EFI WATER
TEMP. SENSOR
SPEED SENSOR
NO. 2(
FOR ECT )
ENGINE AND ECT ECU
CHE CK CONNE CTOR
VC VTA IDL2 E2 VC VTA IDL E2
4321 4321
C3
S4
E2
T2
S9
B
E9
,E10
A
P
(
W/ TRACTION CONTROL )
( W/ TRACTION CONTROL )
( W/ TRACTION CONTROL )
( W/ TRACTION
CONTROL )
BR
B
26
R
G1
B
25
Y
G2
B
7
B
G±
VF2
NE
G±
G2 B
79
W±B
EO2
B
80
W±B
EO1
I33 I33 B
69
BR
E1
W±B W±B
2341
D13
DISTRIBUTOR
BR
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128
ECT AND A/T INDICATOR
POWER NORMAL
3 4
71529 1 2 IJ 2
3
IK1
5IK1 2IK1 22
IJ 1
6
IK1
21
IG2
7
1E
12
1K
4
3D
3
3D
63B 43B
53D
3A
4
3D13 1H
12
B
76
NSW A
18
P A
9
2 A
10
L A
2
SP1
B
17 TT
A
19 TE2
A
28 OD2
IK 1 4
IK 1 3 I19
A
14
IJ1
10
GR±Y LG G±O G±O Y
Y
G
W
G±O
GR±R W±B
Y
Y
Y
ENG TE1 TT TE2 ECT
Y
Y B±W
B±W
G±O
G
W
P
P
P
P G±R
G±Y
GR±R
GR±R
GR±Y
LG
G±R G±Y
GR±R
W±B GR±R GR±R G±O
FROM POWER SOURCE SYSTEM
(
SEE PAGE 56 )
5
7. 5A
ST
10A
GAUGE
ECT PATTERN
SELECT SW
ENGINE AND ECT ECU
O/D MAIN
SW
TDCL E8
E9 , E1 0
T6
O5
A A
10IH
BR
A
E20
IK1
6
IK1
7
2
2 A
13
A
15
SHORT
CONNE CTOR
L±R L±R
R
32
OU T GND
L±R
R
1
VCC SPEED SENSOR
NO. 1 S3
Y
A
B
B
S22 A
,S23
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130
ECT AND A/T INDICATOR
THIS SYSTEM, ELECTRICALLY CONTROLS THE LINE PRESSURE, THROTTLE PRESSURE, LOCK±UP PRESSURE AND\
ACCUMULATOR
PRESSURE ETC. THROUGH THE SOLENOID VALVE. THE ECT IS A SYSTEM WHICH PRECISELY CONTROLS GEAR SHIFT TIMING AND
LOCK±UP TIMING IN RESPONSE TO THE VEHICLE'S DRIVING CONDITIONS AND THE ENGINE OPERATING CONDITIONS DETECTED
BY VARIOUS SENSORS, MAKING SMOOTH DRIVING POSSIBLE BY SHIFT SELECTION FOR EA\
CH GEAR WHICH IS THE MOST
APPROPRIATE TO THE DRIVING CONDITIONS AT THAT TIME, AND CONTROLS THE ENGINE TORQUE DURING SHIFTING TO ACHIEVE
OPTIMUM SHIFT FEELING.
1. GEAR SHIFT OPERATION
WHEN DRIVING, THE ENGINE WARM UP CONDITION IS INPUT AS A SIGNAL TO TERMINAL (B)44 OF THE ECU FROM THE EFI WATER
TEMP. SENSOR AND THE VEHICLE SPEED SIGNAL FROM SPEED SENSOR NO.2 IS INPUT TO TERMINAL (B)23 OF THE ECU. AT THE
SAME TIME, THE THROTTLE VALVE OPENING SIGNAL FROM THE THROTTLE POSITION SENSOR (MAIN) IS INPUT TO TERMINAL
(B)43 OF THE ECU AS ENGINE RPM CONDITION (IDLING, HIGH LOAD AND ACCELERATION CONDITIONS) SIGNAL.
BASED ON THESE SIGNALS, THE ECU SELECTS THE BEST SHIFT POSITION FOR DRIVING C\
ONDITIONS AND SENDS CURRENT TO
THE ECT SOLENOIDS.
WHEN SHIFTING TO 1ST SPEED, THE CURRENT FLOWS FROM TERMINAL (B)10 OF THE ECU " TERMINAL 1 OF ECT SOLENOIDS "
GROUND AND CONTINUITY TO NO.1 SOLENOID CAUSES THE SHIFT (NO.2 SOLENOID DOES NOT HAVE CONTINUITY AT THIS TIME).
FOR 2ND SPEED, THE CURRENT FLOWS SIMULTANEOUSLY FROM TERMINAL (B)9 OF THE ECU " TERMINAL 2 OF ECT SOLENOIDS
" GROUND, AND FROM TERMINAL (B)10 OF THE ECU " TERMINAL 1 OF ECT SOLENOIDS " GROUND, AND CONTINUITY TO NO.1
AND NO.2 SOLENOIDS CAUSES THE SHIFT.
FOR 3RD SPEED, THERE IS NO CONTINUITY TO NO.1 SOLENOID, ONLY TO NO.2 SOLENOID, CAUSING THE SHIFT.
SHIFTING INTO THE 4TH SPEED (OVERDRIVE) OCCURS WHEN NO CURRENT FLOWS TO NO.1 AND NO.2 SOLENOIDS. THE NO.4
SOLENOID (FOR ACCUMULATOR BACK PRESSURE MODULATION) IS INSTALLED TO ADJUST THE BACK PRESSURE ON THE
ACCUMULATOR AND CONTROL THE HYDRAULIC PRESSURE DURING SHIFTING AND LOCK±UP IN \
ORDER TO PROVIDE SMOOTH
SHIFTING WITH LITTLE SHIFT SHOCK.
2. LOCK±UP OPERATION
WHEN THE ECT ECU DECIDES, BASED ON EACH SIGNAL, THAT THE LOCK±UP CONDITION HAS BEEN MET, THE CURRENT FLOWS
FROM " TERMINAL (B)8 OF THE ECU " TERMINAL 3 OF THE ECT SOLENOID " GROUND, CAUSING CONTINUITY TO THE LOCK±UP
SOLENOID AND CAUSING LOCK±UP OPERATION.
3. STOP LIGHT SW CIRCUIT
IF THE BRAKE PEDAL IS DEPRESSED (STOP LIGHT SW ON) WHEN DRIVING IN LOCK±UP CONDITION, A SIGNAL IS INPUT\
TO
TERMINAL (A)4 OF THE ECU. THE ECU OPERATES AND CUTS THE CURRENT TO THE SOLENOID TO RELEASE LOCK±UP.
4. OVERDRIVE CIRCUIT
*O/D MAIN SW ON
WHEN THE O/D MAIN SW IS TURNED ON (SW POINT IS OPEN), A SIGNAL IS INPU\
T TO TERMINAL (A)28 OF THE ECU AND THE ECT
CAUSES SHIFT TO OVERDRIVE WHEN THE CONDITIONS FOR OVERDRIVE ARE MET.
* O/D MAIN SW OFF
WHEN THE O/D MAIN SW IS TURNED OFF (SW POINT IS CLOSED), THE CURRENT FLOWI\
NG THROUGH THE O/D OFF INDICATOR
LIGHT FLOWS TO GROUND BY WAY OF THE O/D MAIN SW AND CAUSES THE O/D OFF INDICATOR LIGHT TO LIGHT UP. AT THE
SAME TIME, A SIGNAL IS INPUT TO TERMINAL (A)28 OF THE ECU AND THE ECT PREVENTS SHIFT INTO OVERDRIVE.
5. ECT PATTERN SELECT SW CIRCUIT
WHEN THE ECT PATTERN SELECT SW IS CHANGED FROM ªNORMALº TO ªPOWERº, THE CURRENT THROUGH THE GAUGE FUSE
FLOWS TO TERMINAL 4 OF ECT PATTERN SELECT SW " TERMINAL 3 " TERMINAL (B)4 OF A/T INDICATOR " TERMINAL (C)23 "
GROUND AND CAUSES THE INDICATOR LIGHT TO LIGHT UP. AT THE SAME TIME, THE CURRENT FLOWS TO TERMINAL (A)18 OF
THE ECU AND THE ECU PERFORMS SHIFT UP AND SHIFT DOWN AT A HIGHER VEHICLE SPEED RANGE COMPARED WITH
ªNORMALº POSITION.
6. KICK DOWN OPERATION
WHEN THE ACCELERATOR IS DEPRESSED FURTHER THAN THE FULL THROTTLE POSITION WHILE DRIVING, THE KICK DOWN SW
TURNS ON AND ITS SIGNAL IS INPUT TO TERMINAL (A)3 OF THE ECU. THEN, THE ECU CONTROLS THE CURRENT WHICH FLOWS
FROM TERMINALS (B)10 AND (B)9 OF THE ECU TO THE NO. 1 AND NO. 2 SOLENOIDS AND SHIFTS DOWN BY TURNING THE
SOLENOIDS ON AND OFF.
7. CRUISE CONTROL
WHEN CRUISE CONTROL OPERATION IS SELECTED A SIGNAL IS INPUT TO TERMINAL (A)12 OF THE ECU FROM CRUISE CONTROL
ECU. AS A RESULT, THE ECU OPERATES AND CONTROLS OVERDRIVE, LOCK±UP AND SO ON FOR SMOOTH DRIVING.
SYSTEM OUTLINE
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