1991 LEXUS SC400 light

30NoiseNOISE PRODUCED BY VIBRATION OR SHOCK
WHILE DRIVING
Is radio properly installed?
Is radio receiver assembly properly installed?
*1 Is radio power amplifier properly installed?
*2 Is woofer amplifier properly installed?*1 Is CD auto changer properly installed?
With vehicle stopped, lightly tap each part.
Is noise produced? Speaker installation faulty.
Radio receiver assembly installation faulty.
Power amplifier installation faulty.
Woofer amplifier installation faulty.
CD auto changer installation faulty. Each part faulty.
Noise produced by static electricity is accululating in the vehicle body\
.
BE±258±
BODY ELECTRICAL SYSTEM AUDIO SYSTEM
WhereEverybodyKnowsYourName

WIRING DIAGRAM
No.SymbolTerminal NameNo.SymbolTerminal NameNo.SymbolTerminal Name
P11
±1SLDFSlide Switch (Forward)P11±13CHKCheckP10±7IGIgnition Switch
2RCLFReclining Switch (Forward)14SSRRReclining Sensor8GND2Ground 2
3FUPFront Vertical Switch (UP)15SSRVRear Vertical Sensor9SLD±Slide Motor (Back)
4RUPRear Vertical Switch (UP)16SSRSSlide Sensor10RCL±Reclining Motor (Down)
5SSFVFront Vertical Switch17SOSerial Communications11FRV±Front Vertical Motor (Down)
6PVCCPosition Sensor Power
Source18SGNDSensor Ground12RRV±Rear Vertical Motor (Down)
7SYSBPower SourceP10±1GNDGround13RRV+Rear Vertical Motor (For-
ward)
8SISerial Communications2SLD+Slide Motor (Forward)14+B2Power Source
9SLDRSlide Switch (Back)3RCL+Reclining Motor (Up)15PNeutral Start Switch
10RCLRReclining Switch (Back)4FRV+Front Vertical Motor (Up)16±±±±
11FDWNFront Vertical Switch (Down)5+BPower Source
12RDWNRear Vertical Switch (Down)6STOPStop Light
BE±272±
BODY ELECTRICAL SYSTEM Power Seat Control System (Driver's Seat)
WhereEverybodyKnowsYourName

Check stop light operation.NG
OK OK
NG Check stop light circuit
(See page
BE±64).
Proceed to next circuit inspection
shown on matrix chart
(See page
BE±276).
Check voltage between terminals STOP
of ECU connector and body ground.
Check and repair harness and connec-
tor between ECU and stop light switch.
WIRING DIAGRAM
Stop Light Circuit
CIRCUIT DESCRIPTION
The stop light switch sends a brake ON of Off signal to the ECU. When the ECU receives a brake ON signal
it prohibits return of the seat.
DIAGNOSTIC CHARTDIAGNOSTIC CHART
BE±298±
BODY ELECTRICAL SYSTEM Power Seat Control System (Driver's Seat)
WhereEverybodyKnowsYourName

OKNG
NGOK
INSPECTION PROCEDURE
1Check stop light operation.
Check that the stop light comes on when the brake pedal is depressed, and turn\
s off when the pedal
is released.C
Check stop light circuit. (See page BE±64).
2Check voltage between terminal STOP of ECU connector and body ground.
C
OK
Hint
PRemove ECU with connectors still connected.
Measure voltage between terminal STOP of ECU and
body gr ound when the brake pedal is depressed and re-
leased.
Brake pedal Voltage
Depressed 10 ± 14 V Released Below 1 V
Proceed to next circuit inspection shown on matrix chart
(See page BE±276).
Check and repair harness and connector between
ECU and stop light switch.
±
BODY ELECTRICAL SYSTEM Power Seat Control System (Driver's Seat)BE±299
WhereEverybodyKnowsYourName

OKNG
NGOK
INSPECTION PROCEDURE
1Check the shift position indicator.
Check that P lights up on the shift indicator when P range is shifted in\
to, and that P is OFF when
shiftin
g into another range.
C
Check shift position indicator circuit (See page BE±141).
2Check voltage between terminal P of ECU connector and body ground.
C
OK
PRemove ECU with connectors still connected.
(1) Turn ignition switch ON.
(2) Measure voltage between terminal P of ECU con-nector and body ground when the shift lever is posi-
tioned to the following ranges.
Shift range
P
1
0
Other than PVoltage
10 ± 14 V
Below 1 V
Proceed to next circuit inspection shown on matrix chart
(See page BE±276).
Check and repair harness and connector between
ECU and connector.
±
BODY ELECTRICAL SYSTEM Power Seat Control System (Driver's Seat)BE±301
WhereEverybodyKnowsYourName

WIRING DIAGRAM
Door Open Detection Switch Circuit
CIRCUIT DESCRIPTION
The door open detection switch comes ON when the door is opened and goes OFF when the door is closed.
Furthermore the door open detection switch circuit has terminal +B connected inside \
the theft deterrent and door
lock ECU, battery positive voltage is applied to terminal DSWD of the wirele\
ss door lock ECU when all doors
are closed, i.e., when the door open detection switch of all doors are O\
FF.
DIAGNOSTIC CHARTDIAGNOSTIC CHART
NG OK
Check open door warning light
circuit (See page
BE±118).
Check operation of open door warning
light
Check voltage between terminal DSWD
of ECU connector and body ground. Proceed to next circuit inspec-
tion show on matrix chart (See
page
BE±454 ).
Check and repair harness and connector
between ECU and door open detection
switch.;
1
2
BE±470±
BODY ELECTRICAL SYSTEM Wireless Door Lock Control System
WhereEverybodyKnowsYourName

OKNG
NGOK
INSPECTION PROCEDURE
1Check operation of open door warning light.
Check that open door warning light comes on when each door is opened, and goes\
off when all doors
are closed.C
Check open door warning light circuit (See page
BE±118 ).
2Check voltage between terminal DSWD of ECU connector and body ground.
C
OK
P1. Remove the rear seat and RH quarter trim panel.
2. Remove the ECU.
3. Wireless door lock main switch on.
Measure voltage between terminal DSWD of ECU con-
nector and body ground, when all doors are closed.
Voltage: 10 ± 14 V
Proceed to next circuit inspection shown on matrix chart
(See page BE±454).
Check and repair harness and connector between ECU and door open detecti\
on switch.
±
BODY ELECTRICAL SYSTEM Wireless Door Lock Control SystemBE±471
WhereEverybodyKnowsYourName

GENERAL INFORMATION
Wiring Color Code
Wire colors are indicated by an alphabetical code.
B = Black L = Blue R = Red
BR = Brown LG = Light Green V = Violet
G = Green O = Orange W = White
GR = Gray P = Pink Y = Yellow
The first letter indicates the basic wire color and the second
letter indicates the color of the stripe.
Connector
1. PIN NUMBERS OF FEMALE CONNECTORNumbered in order from upper left to lower right.
2. PIN NUMBERS OF MALE CONNECTOR
Numbered in order from upper right to lower left.
HINT: When connectors with different of the same number of
terminals are used with the same parts, each connector
name (letter of the alphabet) and pin number is specified.
3. DISTINCTION OF MALE AND FEMALE CONNECTORS Male and female connectors are distinguished by shape of
their internal pins.
(a) All connectors are shown from the open end, and thelock is on top.
(b) To pull apart the connectors, pull on the connector itself, not the wires.
HINT: Check to see what kind of connector you are discon-
necting before pulling apart.
BE±2
±
BODY ELECTRICAL SYSTEM General Information
WhereEverybodyKnowsYourName