1991 LEXUS SC400 turn signal

OKNG
OKNG
OKNG
INSPECTION PROCEDURE
1Check operation of stop light.
Check if the stop lights go on and off normally when the brake pedal is operated and released.C
Check and repair stop light circuit (See BE section).
2Check stop light signal.
C
OK
1. Connect voltmeter to the terminals TT and E1 of the
DLC2.
2. Turn ignition switch ON (Do not start the engine).
3. Fully depress the accelerator pedal until the volt- meter indicates 8 V and hold it.
4. Depress and release the brake pedal and check the
voltage.
Proceed to next circuit inspection shown on matrix chart
(See page AT±66).
3Check harness and connector between ECM and stop light switch (See page\
IN±33).
Repair or replace harness or connector.
Check and replace ECM.
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A304E (1UZ±FE) AUTOMATIC TRANSMISSION TROUBLESHOOTINGAT±109
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OKNG
OKNG
OKNG
INSPECTION PROCEDURE
1Check voltage between terminal P of ECM connector and body ground.
C
OK
Hint
P1. Connect the check harness A to the ECM (See EGsection).
2. Turn ignition switch ON.
Measure voltage between terminal P of ECM connector
and body ground when the pattern select switch is set
to the PWR (POWER) position and NORM (NORMAL)
position.
The ECM uses the normal pattern signal if the power
signal is not input.
Proceed to next circuit inspection shown on matrix chart
(See page AT±66).
2Check pattern select switch.
C
OK
PDisconnect pattern select switch connector. (See BO
section).
Measure resistance between terminals 1 and 2 of pat-
tern select switch connector when the select switch is
set to PWR and NORM positions.
Replace pattern select switch.
3Check harness and connector between ECM and pattern select switch, patte\
rn select switch
and battery (See page IN±33).
Repair or replace harness or connector.
Check and replace ECM.
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A304E (1UZ±FE) AUTOMATIC TRANSMISSION TROUBLESHOOTINGAT±111
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2. HYDRAULIC CONTROL SYSTEMThe hydraulic control system is composed of the oil pump, the valve body, the solenoid valves, the accumu-
lators, the clutches and brakes, as well as the fluid passages which connect al\
l of these components.
Based on the hydraulic pressure created by the oil pump, the hydraulic control system governs the hydrau-
lic pressure acting on the torque converter clutch, clutches and brakes \
in accordance with the vehicle driv-
ing conditions.
There are 4 solenoid valves on the valve body.
The No.1 and No.2 solenoid valves are turned on and off by signals from the ECM to operate the shift
valves, and change the gear shift position.
The No.3 solenoid valve is operated by signals from the ECM to engage or di\
sengage the lock±up clutch
of the torque converter clutch.
The No.4 solenoid valve is operated by signals from the ECM to control the \
engagement speed and reduce
gear shift shock.
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A304E (1UZ±FE) AUTOMATIC TRANSMISSION OPERATIONAT±7
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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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31NoiseNOISE PRODUCED WHEN ENGINE STARTS
Whistling noise which becomes high±pitched when
accelerator strongly depressed, disappears shortly
after engine stops.Whining noise occurs when A/C is operating.
Scratching noise occurs during sudden accel-
eration, driving on rough roads or when ignition
switch is turned on.
Clicking sound heard when horn button is
pressed, then released. Whirring/grating sound
when pushed continuously.
Murmuring sound, stops when engine stops. Tick±tock noise, occurs in coordination with
blinking of flasher.
Noise occurs during window washer operation.Scratching noise occurs while engine is running,
continues a while even after engine stops.Scraping noise in time with wiper beat.
Other type of noise. Alternator noise.
A/C noise.
Fuel gauge noise.
Horn noise.
Ignition noise. Turn signal flasher noise.
Washer noise. Water temp. gauge noise.
Wiper noise.
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BODY ELECTRICAL SYSTEM AUDIO SYSTEMBE±259
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DESCRIPTION
The Power Seat Control System carries out seat slide, front vertical, rear \
vertical, reclining and lumbar support
position adjustments electrically. Power seat switch and lumbar support switch.
In addition, operation of the memory switch makes it possible to store the positions of the slide, front vertical,
rear vertical and reclining adjustments in memory and return to the posi\
tion.
The component parts of this system and their function are described in t\
he following table.
 Parts Name\
 \
Function
 








Driver's Seat ECU
\
 
\


\


\


\

\

The seat ECU controls power operation, memory operation, and position re\
turn
operation of the power seat. When input is received from the power seat \
switch,
the relay inside the ECU is controlled and the power seat operates. The \
seat
memory and position return are controlled by mutual communication betwee\
n the
electrically operated Tilt and Telescopic ECU and the seat ECU.
 

Power Seat Switch\
 
\

\

Operation of this switch sends slide, front vertical, rear vertical, rec\
lining signals
to ECU.
 




Driving Position
Memory and Return
Switch\
 
\


\

\

Memory and Return Signals are sent to the seat ECU via the Tilt and Telescopic
ECU.
 






Lumbar Support
Switch
\
 
\


\


\

\

This switch is supplied with power from the DOOR fuse. When the switch i\
s
operated, power is supplied to the lumbar support motor controlling the \
direction
in which the motor turns and turning the current ON and OFF. This switch is not
connected to the ECU and the adjustment position cannot be stored in mem\
ory
for return operation.
 

Position Sensor
\
 
\

\
This sensor sends signals on the position of each motor (slide, front v\
ertical, rear
vertical and reclining) to the ECU for use in memory and return.
 

*Motor
\
 
\

\

These motors operate on current from the driver's seat ECU moving the various
parts of the seat directly. Each motor has a built±in circuit breaker.
*: Slide, Front Vertical, Rear Vertical, Lumbar Support and Reclining.
Motors contained in each seat are described in the following table.
 Motor Slide Front
Vertical
 Rear
Vertical
 Reclining Lumbar
Support 

Seat 

Motor 


Vertical
Motor
 


Vertical
Motor
 


g
Motor 


Support
Motor
 Driver's Seat O* O* O* O* O
*: Operated by the memory and return functions. BE±266
±
BODY ELECTRICAL SYSTEM Power Seat Control System (Driver's Seat)
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HOW TO PROCEED WITH TROUBLESHOOTING
Perform troubleshooting in accordance with the procedure on the following page.\

CUSTOMER PROBLEM ANALYSIS
Using the customer problem analysis check sheet for reference, ask the c\
ustomer in as much detail as
possible about the problem.
\b PROBLEM SYMPTOM CONFIRMATION,  SYMPTOM SIMULATION.
Confirm the problem symptoms. If the problem does not reappear, be sure to simulate the problem using
the ºProblem Simulation Methodsº.
When checking the problem symptoms, pay attention to the following points to\
accurately define the symp-
toms and the extent of the problem:
For ºNot Functioningº problems:
(1) Is the problem only in one part (e.g. ºreclining onlyº), or ever\
ything?
(2) Is the problem only for manual operation, only for position return opera\
tion, or for both manual and position return operation?
(3) Is tilt, telescopic and outer mirror operation normal?
(4) Does the problem occur with the ignition key inserted, or not inserted?
 MATRIX CHART OF PROBLEM SYMPTOMS
Confirm the order of inspection on the matrix chart for the particular problem symptom involved. For ºNot
Functioningº problems, pay attention to the points in \b. to find out the specifics of the problem, then choose
the most appropriate problem symptom from among those listed on the matr\
ix chart, and proceed with trou-
bleshooting accordingly.
 CIRCUIT INSPECTION
Proceed with diagnosis of each circuit in accordance with the inspection\
order confirmed in .
Determine whether the cause of the problem is in the sensor, actuators, wire harness and connectors, or
the ECU.
 POSITION SENSOR CHECK
This function checks that the signal from each position sensor is correctly input into\
the ECU when the
manual switch is turned ON. The instructions for this diagnosis are included in\
the flow chart for the position
sensor circuit.
 REPAIR
After the cause of the problem is located, perform repairs by following the i\
nspection and replacement pro-
cedures is this manual.
 CONFIRMATION TEST
After completing repairs, confirm that the problem is eliminated and that tilt, telescopic and outer mirror
operation is normal.
BE±268
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BODY ELECTRICAL SYSTEM Power Seat Control System (Driver's Seat)
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STANDARD VALUE OF ECU TERMINAL
TerminalsSymbolsWiringColorConditionStandard Value
P11±1 eBody
GroundSLDF eBody
Ground
LSeat moved forward using slide SWBelow 1 VL
Others10±14 V
P11±2 eBody
GroundRCLF eBody
GroundY±RSeat moved forward using reclining SWBelow 1 V
Others10±14 V
P11±3 eBody
GroundFUP eBody
GroundL±YSeat raised using front vertical SWBelow 1 V
Others10±14 V
P11±4 eBody
GroundRUP eBody
GroundY±GSeat raised using rear vertical SWBelow 1 V
Others10±14 V
P11±5 eP11±18SSFV eSGNDLG±R eBR±BFront vertical operation0 V e8 V
P11±6 eP11±18PVCC eSGNDVe BR±BManual position return operation8 V
P11±7 eP10±1SYSB eGNDRe W±BAlways10±14 V
P11 8SIW
Signals between power seat ECU & tilt
telescopic ECU0 V e12 V
P11±8SIW
OthersResistance
(approx. 2.5 k
)
P11±9 eBody
GroundSLDR eBody
Ground
L±BSeat moved to rear using slide SWBelow 1 VL±B
Others10±14 V
P11±10 eBody
GroundRCLR eBody
Ground
Y±BSeat moved to rear using reclining SWBelow 1 VY±B
Others10±14 V
P11±11 eBody
GroundFDWN eBody
Ground
L±RSeat lowered using front vertical SWBelow 1 VL±R
Others10±14 V
P11±12 eBody
GroundRDWN eBody
Ground
Y±LSeat lowered using rear vertical SWBelow 1 VY±L
Others10±14 V
P11±13CHK
P11±14 eP11±18SSRR eSGNDV±W eBR±BReclining operation0 V e8 V
P11±15 eP11±18SSRV eSGNDY±G eBR±BRear vertical operation0 V e8 V
P11±16 eP11±18SSRS eSGNDLG eBR±BSlide operation0 V e8 V
±
BODY ELECTRICAL SYSTEM Power Seat Control System (Driver's Seat)BE±273
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