fuse box LEXUS SC400 1991 Service Repair Manual

ECU DATA MONITOR USING LEXUS HAND±HELD TESTER
1. Hook up the LEXUS hand±held tester to the DLC2.
2. Monitor the ECU data by following the prompts on the testerscreen.
HINT: LEXUS hand±held tester has a ªSnapshotº function
which records the monitored data.
Please refer to the LEXUS hand±held tester operator's
manual for further details.
DIAGNOSTIC TROUBLE CODE CLEARANCE
1. Using SST, connect terminals Tc and E1 of DLC2 or DLC1. SST 09843±18020
2. IG switch ON.
3. Clear the diagnostic trouble codes stored in ECU by depressing the brake pedal 8 or more times within 3 seconds.
4. Check that the warning light shows the normal code.
5. Remove the SST from the terminals of DLC2 or DLC1.
6. Connect the Short Pin to DLC1.
HINT: Cancellation can also be done by removing the DOME
fuse, but in this case, other memory systems will also be can-
celled out.
ECU TERMINAL VALUES MEASUREMENT USING LEXUS BREAK±OUT±BOX AND LEXUS HANDHELD TESTER
1. Hook up the LEXUS hand±held tester and LEXUS
break±out±box to the vehicle.
2. Read the ECU input/output values by following the prompts on the scan tool screen.
HINT: LEXUS hand±held tester has a ªSnapshotº function.
This records the measured values and is effective in the diag-
nosis of intermittent problems.
Please refer to the LEXUS hand±held tester/LEXUS break±
out±box operator's manual for further details.
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±77
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90
ILLUMINATION
1B
2
1K
5 3G
83A 12
3A
2
3A
93G 13A10
1I
3
1K
11
1J
1 3A
1
OFF
TAIL
HEAD 2 1 1 2
1G1
5
IF 1E
18 RL RV RE TC
RL RE
826 RV
7 314
4
3
4
6
G±O
G±O
G±O
G±O
L±B
Y±V
BR L G±O
W±B
W±G
W±B
L
W±B
WW±L
G±L
LG ±B G±W G±W W±L
LG±BG±W
W±B G±O
(US A )
( CANADA )
(USA )
TAILLIGHT
RELAY
INTE GRATION
RE LAY
BATTERY FUSE
BLOCK COMBINATION
SW
120A ALT 100A AM1
INTEGRATION
RE LAY
7. 5A
PANEL
GLOVE BOX
LIGHT SW GLOVE BOX LIGHT
RHEOSTATCOMBINATION METER
(
CANADA )
LIGHT
CONTROL SW
C15
F9
G2 G1I16I16
C12
R9
W
23 15 3C
1
A
17
B
3B 4B5B 2
A
,C14 B
G±O
(
USA )
( CANADA )
B
11
A
4
B
5
B
10
B3 12
(CANADA )
A
A
TC E I LL ± T
W±B
W±G
L
I18
L
L
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OVERALL ELECTRICAL WIRING DIAGRAM
1234
14 LEXUS SC300
1J
41J 7 1J
5
2
44
11
1B
4
441K
13 4 1A
52
22
3 1
4
2
3
2
4
1
5 22
13 IE1
2Bb1
10 IG2
16 IG1
3232
4
ACC
IG1
ST1
AM1 3
2
2 1
IF BL Bk EB
4Bb1
3H
14
1E
18 3A
1 11
3232 1B
1
1J
8
3A
5
1D
11H 4
1C
7 1E
2
3F
5
4IP2
10 Bc 2
20 IP1 4
1
2 2
IJ
BL
B
B
W± B
W
W± LB
WB
B
B
B±R
B
B
W± B
W± B
W± B
W±B
W± B
G
L
R± Y R± Y B
R± Y
W± B
W±B W±B W±B W±B
W± B L
G
GL
R±L
L±R B
L±R
L±R B
W± B
W± B W± B
W± B
W±B
W± B
L±R P±L
L±R B B
P±L
B± Y
B±Y
120A ALT 100A AM1F9
FUSE BOX4
3
I15
IGNITION SW
40A
IGSW 15A
ECU±I G
15A
SEAT±HTR
SEAT HEATAER SW
S18
SEAT HEATER RH
( f or Driver' s Seat Cushion )
S16
SEAT HEATER LH
( f or Pas senger ' s Seat Cus hion )SEAT HEATER
RELAY
W Y
W Y
W± B
To A/C Con tro l
Assembly< 22±7>
BATTERY
S1 7
SEAT HEAT ER RH
( for Driver' s
Se at Bac k )
S1 5
SEAT HEAT ER LH
( for Passenger' s
Se at Bac k )
DEFOGGER
RELAY
10A
HT R
50A
DEFOGGER 10A
MI R± HT R
4 3
LH
RH
MIRROR HEATER
[ REMOTE CONTROL MIRROR]
C22
CHOKE COI L
RE AR WI NDOW
DE FOGGE R
C11
CIGARETTE
LIGHTER
15A
CI G
N2
NOI SE
FILTER
( for Def ogger Syst em )
Power
Source Seat Heater
Rear Window Defogger and
Mirror HeaterCigarette
Lighter
6 54
Lef t kick panel Under t he center pillar
RHUnd er t he
center pillar
LHFr ont s ide of
left fender
Under the
center
pillar RHRight k ic k panel
2
1
1
1J 10
1D 8
3F 2Ba2
Ba1
14
5Ba2 Ba1
12 *
1
* 2
* 1
* 2
3 BY1 2 BU1
5B 7A
10 A 3 A3B 4B
1
B
8
A (
A/ T )
( M/ T )
(
A/T )
( M/T )
*2: (
w/ o Memory Power Seat )
*
1:
(
w/ Me mo r y P ower S ea t )
L
G
W±B (
* 3
)
8E 8E
5F
(
* 4
)
5F 4F 7E
( * 4)
4F
(
* 3)
7E (
* 3)
( * 4)
( * 3
)
( * 4
)
*
3: (
w/ Me mor y )
* 4: (
w/ o Memo r y )
9876 4321 5 54 21
3
E
R16, R17 F
R1 6, R17
MI RROR HE A TER
[ R EMOT E C ON RT OL MI RR OR ] MIRROR HEATER
[REMOTE CONRTOL
MIRROR]
123456
12 34
5 6 10 11 789B
(
A/T )
S24
A
(
M/T )
T12
S2 4 B , T1 2 A
SEAT HEATAER SW
1C
1D
R14 C , R15 D
(* 3) (
* 4 )
L
B
1
1
C
R14 D
R15
REAR WI NDOW DEFOGGER
R17
R1 6 E F
EF
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11015
14
13 12
12345 123
GRAY GRAY
C14 P 1 P 2 S 3
X
2 2
BA
S22 S23
187
THE PPS (HYDRAULIC REACTION TYPE) CONTROLS THE HYDRAULIC PRESSURE APPLIED\
TO THE HYDRAULIC REACTION
CHAMBER IN THE GEAR BOX CONTROL UNIT USING THE PPS ECU, TO CHANGE THE STEERING FORCE AND PROVIDE OPTIMUM
STEERING FEELING AT ANY VEHICLE SPEED AND UNDER ANY STEERING CONDITIONS.
(PPS OPERATION)
WHEN THE IGNITION SW IS TURNED ON THE STARTING CURRENT FLOWS FROM THE ECU±IG FUSE TO TERMINAL 4 OF THE PPS
ECU. THE SPEED SENSOR MONITORS THE VEHICLE SPEED AND TRANSMITS CONTROL SIGNALS TO TERMINAL 3 OF THE ECU.
WHEN THE VEHICLE SPEED IS LOW, THE PPS ECU SENDS A HIGHER±VOLTAGE FROM TERMINAL 1 OF THE ECU " TERMINAL 1 OF
THE SOLENOID VALVE " TERMINAL 2 " TERMINAL 5 OF THE ECU " TERMINAL 2 " GROUND, INCREASING THE SOLENOID VALVE
OPENING ANGLE TO PROVIDE COMFORTABLE STEERING OPERATION. WHEN THE VEHICLE SPEED IS HIGH, THE PPS ECU
DECREASES THE SOLENOID VALVE OPENING ANGLE BY REDUCING THE VOLTAGE TO THE VALVE TO PROVIDE RESPONSIVE
STEERING FEELING.
P 1 PPS SOLENOID
1±2 : APPROX. 7.7
(25 °C, 77°F)
P 2 PPS ECU
4±GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
2±GROUND : ALWAYS CONTINUITY
1±5 : APPROX. 0.8A WITH VEHICLE SPEED BELOW 20 KM/H ( 12 MPH)
APPROX. 0.45A WITH VEHICLE SPEED AT 80 KM/H ( 48 MPH)
APPROX. 0.2A WITH VEHICLE SPEED ABOVE 160 KM/H ( 96 MPH)
: PARTS LOCATION
CODESEE PAGECODESEE PAGECODESEE PAGE
C1428P 229S22B29
P 127S 327S23A29
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CODESEE PAGEJUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)
1E20INSTRUMENT PANEL WIRE
1H20COWL WIRE1I20COWL WIRE
3A22INSTRUMENT PANEL WIRE3D22INSTRUMENT PANEL WIRE
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CODESEE PAGEJOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)
IG236INSTRUMENT PANEL WIRE AND COWL WIRE (R/B NO. 5)
IJ136ENGINE WIRE AND COWL WIRE (RIGHT KICK PANEL)IJ236ENGINE WIRE AND COWL WIRE (RIGHT KICK PANEL)
IK136ENGINE WIRE AND INSTRUMENT PANEL WIRE (RIGHT KICK PANEL)
: GROUND POINTS
CODESEE PAGEGROUND POINTS LOCATION
IH36UNDER THE ASHTRAY LH
IJ36RIGHT KICK PANEL
SYSTEM OUTLINE
SERVICE HINTS
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