1991 LEXUS SC300 code 32

OKNG
OKNG
OKNG
INSPECTION PROCEDURE
1Check operation of O/D Main Switch
C
OK
Hint
C
OK
1. Turn ignition switch ON.
2. Check ªO/D OFFº light when O/D main switch ispushed in to ON.
ªO/D OFFº light goes off.
3. Check ªO/D OFFº light when O/D main switch is pushed again, to OFF.
ªO/D OFFº light lights up.
If the ªO/D OFFº lights blinks when the O/D main switch
is pushed in to ON, a malfunction is occurring in the sys-
tem.
Check the diagnostic trouble code.
Go to step
.
2Check voltage between terminal OD2 of ECM connector and body ground.
C
OK
P1. Connect the check harness A to the ECM (See EG
section).
2. Turn ignition switch ON.
Check voltage between terminal OD2 of ECM and body
ground
Proceed to next circuit inspection shown on matrix chart
(See page AT±66).
3Check harness and connector between O/D off indicator light and ECM (Se\
e page IN±33).
Repair or replace harness or connector.
Check and replace ECM.
AT±114±
A304E (1UZ±FE) AUTOMATIC TRANSMISSION TROUBLESHOOTING
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AT±66
IN±33
WIRING DIAGRAM
TE1 Terminal Circuit
CIRCUIT DESCRIPTION
ECM displays diagnostic trouble codes using the O/D OFF indicator light \
when terminals TE and E of the
DLC2 or DLC1 are connected.
DIAGNOSTIC CHARTDIAGNOSTIC CHART
AT±118±
A304E (1UZ±FE) AUTOMATIC TRANSMISSION TROUBLESHOOTING
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HOW TO PROCEED WITH TROUBLESHOOTING
AT09N±0D
1. CUSTOMER PROBLEM ANALYSISUsing the customer problem analysis check sheet for reference, ask the c\
ustomer in as much detail as
possible about the problem.
2. CHECK AND CLEAR THE DIAGNOSTIC TROUBLE CODES (PRECHECK) Before confirming the problem symptom, first check if there are any diagnostic\
trouble malfunction codes
stored in memory. When there are malfunction codes, make a note of them, then clear them\
and proceed
to ª3. Problem Symptom Confirmationº.
3. PROBLEM SYMPTOM CONFIRMATION Confirm the problem symptoms.
4. SYMPTOM SIMULATION If the problem does not reappear, be sure to simulate the problem by mainly checking the circuits indica\
ted
by the diagnostic trouble code in step 2., using ªProblem Simulation me\
thodº.
5. DIAGNOSTIC TROUBLE CODE CHECK Check the diagnostic trouble codes. Check if there is abnormality in the\
sensors or the wire harness.
If a malfunction code is output, proceed to ª6. Diagnostic Trouble Code Chartº.
If the normal code is output, proceed to ª11. Matrix Chart of Problem Symptomsº.
Be sure to proceed to ª6. Diagnostic Trouble Code Chartº after the steps 2. and 3. are completed.
If troubleshooting is attempted only by following the malfunction code sto\
red in the memory is output, errors
could be made in the diagnosis.
6. DIAGNOSTIC TROUBLE CODE CHART If a malfunction code is confirmed in the diagnostic trouble code check, p\
roceed to the inspection proce-
dure indicated by the matrix chart for each diagnostic trouble code.
7. PRELIMINARY CHECK Carry out a preliminary check of the transmission oil level, throttle ca\
ble adjustment, etc.
8. SHIFT POSITION SIGNAL CHECK
Carry out the shift position signal check when the transmission gears do\
not up±shift, down±shift or lock±
up. This is to check the output condition from the ECM to each solenoid. If the r\
esults are NG, then it is
likely that the trouble is in the electrical system (particularly in th\
e sensors or the ECM).
Proceed to Part 1 (Electrical System) under ª11. Matrix Chart of Problem Symptomsº. If all the circuits speci-
fied in Part 1 are OK, check the ECM and replace it.
9. MECHANICAL SYSTEM TEST (Stall Test, Time Lag Test, Line Pressure Test, Accumulator Back Pressure Test)
If the malfunction is found in the stall test, time lag test, line press\
ure test or accumulator back pressure
test, check the parts indicated in the respective tests. If the problem is th\
at ªshift shock is largeº, perform
the accumulator back pressure test.
10. MANUAL SHIFTING TEST If the results of the manual driving test are NG, it is likely that the trouble is in the mechanical system or
hydraulic system. Proceed to Part 2 (Mechanical System) under the Matrix Chart \
of Problem Symptoms.
AT±32
±
A304E (1UZ±FE) AUTOMATIC TRANSMISSION TROUBLESHOOTING
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11. MATRIX CHART OF PROBLEM SYMPTOMSIf the normal code is confirmed in the diagnostic trouble code check, perform inspection according to the
inspection order in the matrix chart of problem symptoms. Perform diagno\
sis of each circuit or part in the
order shown in the Matrix Chart. The Matrix Chart contains 3 chapters, Electronically Controlled Circuits
in Chapter 1, On±vehicle Inspection in Chapter 2 and Off±vehicle Inspection in Chapter 3. If all the circuits
indicated in Chapter 1 are normal, proceed to Chapter 2. If all the parts indicated i\
n Chapter 2 are normal,
proceed to Chapter 3. If all the circuits and parts in Chapter 1±Chapter 3 are normal and the trouble still
occurs, check and replace the ECM.
12. CIRCUIT INSPECTION Perform diagnosis of each circuit in accordance with the inspection order confirmed in 6. and 11. Judge
whether the cause of the problem is in the sensor, actuators, wire harness and connectors, or the ECM.
In some cases, the Flow Chart instructs that a throttle signal check, brak\
e signal check or kick down signal
check (in test mode) be performed. These are diagnosis functions used \
to check if signals are being input
correctly to the ECM.
13. PARTS INSPECTION Check the individual parts of the mechanical system and hydraulic system in t\
he order of the numbers indi-
cated in the Matrix Chart.
14. REPAIRS After the cause of the problem is located, perform repairs by following the i\
nspection and replacement pro-
cedures in this manual or '94 A340E and A341E Automatic Transmission Repair Manual (for LEXUS
SC400).
15. CONFIRMATION TEST
After completing repairs, confirm not only that the malfunction is eliminated\
, but also conduct a test drive,
etc., to make sure the entire electronically controlled transmission system i\
s operating correctly.
±
A304E (1UZ±FE) AUTOMATIC TRANSMISSION TROUBLESHOOTINGAT±33
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COMPONENTS (Cont'd)
HINT: Screw sizes in the illustration on the previous page
are indicated using the code below for removal and installa-
tion of safety pad.mm (in.)
Code
ShapeSizeCodeShapeSizeCodeShapeSize
j = 8
(0.32)
L = 20
(0.79)j = 5
(0.20)
L = 18
(0.71)
j = 8
(0.32)
j = 6
(0.24)
L = 16
(0.63)j = 5
(0.20)
L = 14
(0.55)
j = 6
(0.24)
j = 6
(0.24)
L = 20
(0.79)j = 5
(0.20)
L = 18
(0.71)j = 5
(0.20)
L = 16
(0.63)
j = 6
(0.24)
L = 25
(0.98)
BO6527
±
BODY Instrument PanelBO±109
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SRS AIRBAG
(See page AB±2)
The LEXUS SC300 is equipped with an SRS (Supplemental Restraint System)\
airbag.
Failure to carry out service operations in the correct sequence could cause the airbag system to deploy,
possibly leading to a serious accident.
When removal or installation of airbag parts and the yellow wire harness\
and connector for the airbag is
necessary, refer to the precautionary notices in the AB section before performing\
the operation.

Work must be started after 20 seconds or longer from the time the ignition switch is set to the LOCK
position and the negative (±) terminal cable is disconnected from the batte\
ry.
(The airbag system is equipped with a back±up power source so that if wor\
k is started within 20 se-
conds of disconnecting the negative (±) terminal cable of the batte\
ry, the airbag may be deployed.

To avoid erasing the memory of each memory system, never use a back±up power supply from
outside the vehicle.

Before repairs, remove the airbag sensors if shocks are likely to be applied t\
o the sensors during
repaires.

The front airbag sensor set bolt has been anti±rust treated. When the\
sensor is removed, always
replace the set bolt with a new one.

If the front airbag sensors, center airbag sensor or steering wheel pad ha\
ve been dropped, or if there
are cracks, dents or other defects in the case, bracket or connector, replace them with new ones.

Never use airbag parts from another vehicle. When replacing parts, repla\
ce them with new parts.

Do not expose the front airbag sensors, center airbag sensor or steering w\
heel pad directly to hot air
or flames.

The airbag system's wire harness is integrated with the cowl wire harness assembly. The wires for the
airbag wire harness are encased in a yellow corrugated tube. All the connector\
s for the system are
also a standard yellow color. If the airbag system wire harness becomes disconnected or the
connector becomes broken due to an accident, etc., repair or replace it as shown \
on page AB±20.

The steering wheel must be fitted correctly to the steering column with the\
spiral cable at the neutral
position; otherwise, cable disconnection and other troubles may result. \
Refer to page AB±14 of this
manual concerning correct steering wheel installation.

When removing the steering wheel pad or handling a new steering wheel pad, i\
t should be placed with
the pad top surface facing up. In this case, the twin±lock type connector lock lever should be in the
locked state and care should be taken to place it so the connector will not be damaged. (\
Storing the
pad with its metallic surface up may lead to a serious accident if the a\
irbag inflates for some reason.)

Grease should not be applied to the steering wheel pad and the pad should not \
be cleaned with
detergents of any kind.

Store the steering wheel pad where the ambient temperature remains below 93 C (200 F), without
high humidity and away from electrical noise.

Information labels are attached to the periphery of the airbag component\
s. Follow the notices.

When the ignition switch is at ACC or ON and the airbag warning light remains on, the cent\
er airbag
sensor assembly has detected a malfunction code. (See page AB±30).
BO±8
±
BODY General Information
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INSPECTION PROCEDURE
1Position sensor check
C
P(1) Remove the driver's seat.
(2) Remove the bolts for the front vertical adjuster andlift the seat cushion up a little.
Notice: If the seat cushion is lifted to high, the har-
ness will be pulled and the clamp may come loose.
(3) Remove the ECU with the connector attached from where it is installed to the underside of the seat
cushion.
(1) Connect terminal CHK of the ECU to body ground to put the ECU into check mode.
(2) Measure the voltage between terminal SO of ECU and body ground.
HINT: Use an analog type meter.
(3) Check that the ªreadyº code is output as shown in the illustration.
±
BODY ELECTRICAL SYSTEM Power Seat Control System (Driver's Seat)BE±295
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1Position sensor check (Cont'd)
OK Code
NG Code
OK
Hint
Hint
(4) Operate the power seat switch and check thechange in the voltage when the seat is moving.
The lumbar support does not have a position sensor, so
the sensor check cannot be done.
(5) The changes in the output voltage when the input signal is normal and when it is abnormal are shown
in the illustrations. Compare the results with those
from (4) and diagnose the condition of each circuit.

The OK and NG codes continue to be output while
the manual switch is ON.

When the seat reaches the limit of movement, e.g.
when the slide position reaches the most forward
or back position, the voltage changes from the OK
code to the NG code.
After operating any of the system functions with no
problem and confirming the OK code and NG code
by comparing the amount of wavering of the
voltmeter needle, inspect the function with a
problem.

The amount of wavering of the voltmeter needle
depends on the meter.
OutputOK Code
NG Code
OK
NG
BE±296±
BODY ELECTRICAL SYSTEM Power Seat Control System (Driver's Seat)
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