1991 LEXUS SC300 code 32

OKNG
2Check harness and connector between battery and No. 4 solenoid valve, No. 4 solenoid valve\
and ECM (See page IN±33).
Repair or replace harness or connector.
Proceed to next circuit inspection shown on ma-
trix chart (See page AT±66). However, when diag.
trouble code 46 is display, check and replace ECM.
±
A304E (1UZ±FE) AUTOMATIC TRANSMISSION TROUBLESHOOTINGAT±85
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DTC62, 63No. 1, No. 2 Solenoid Valve Circuit
CIRCUIT DESCRIPTION
Shifting from 1st to O/D is performed in combination with ON and OFF of the No. \
1 and No. 2 solenoid valves
controlled by ECM. If an open or short circuit occurs in either of the solenoid valves\
, the ECM controls the remain-
ing normal solenoid to allow the vehicle to be operated smoothly (Fail saf\
e function.
Fail Safe Function
If either of the solenoid valve circuits develops a short or an open, th\
e ECM turns the other solenoid ON and
OFF to shift to the gear positions shown in the table below. The ECM also turns the lock±up solenoid valve OFF
at the same time. If both solenoids malfunction, Hydraulic control cannot \
be performed electronically and must
be done manually.
Manual shifting as shown in the following table must be done. (In the case of \
a short circuit, the ECM stops send-
ing current to the short circuited solenoid).
 

Position
 

NORMAL
 

NO. 1 SOLENOID
MALFUNCTIONING 

NO. 2 SOLENOID
MALFUNCTIONING 

BOTH SOLENOIDS
MALFUNCTIONING
 Position Solenoid valve Gear Solenoid valve Gear Solenoid valve Gear Gear when shift selectoris
  No. 1 No. 2 Gear No. 1 No. 2 Gear No. 1 No. 2 Gear 
Gear when shift selectorismanually operated
  ON OFF 1st x ON 3rd ON x 1st O/D
 D ON ON 2nd x ON 3rd OFF x O/D O/D
  OFF ON 3rd x ON 3rd OFF x O/D O/D
  OFF OFF O/D x OFF O/D OFF x O/D O/D
  ON OFF 1st x ON 3rd ON x 1st 3rd
 2 (S) ON ON 2nd x ON 3rd OFF x 3rd 3rd

()
OFFON3rdxON3rdOFFx3rd3rd 
L
 ON OFF 1st x OFF 1st ON x 1st 1st L ON ON 2nd x ON 2nd ON x 1st 1st
x: Malfunctions
Check the No. 1 solenoid when diagnostic trouble code 62 is output and check t\
he No. 2 solenoid when diagnos-
tic trouble code 63 is output.
DTC No.DTC Detecting ConditionTrouble Area
62, 63

Solenoid resistance of 8
or less is detected (*)
8 times or more when solenoid is energized.

Solenoid resist ance of 100 k
or more is detected
(*) 8 times or more when solenoid is not energized.
Solenoid valve.

Harness or connector between solenoid and
ECM.

ECM
(*) If the above failures are detected less than 8 times, the ECM memo\
rizes the malfunction code but the O/D
OFF indicator light doesn't blink. AT±90
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OKNG
OKNG
INSPECTION PROCEDURE
1Check No. 1, No. 2 solenoid valves.
C
OK
P
C
P
OK
C
Electrical Check
1. Jack up the vehicle.
2. Remove oil pan.
3. Disconnect solenoid connector.
Measure resistance between solenoid connector and
body ground.
Resistance: 10 ± 16

Connect positive
lead to terminal of solenoid connec-
tor, negative  lead to solenoid body.
The solenoid makes an operating noise.
Mechanical Check
1. Remove the oil pan.
2. Remove the No. 1 and No. 2 solenoid valves.
1. Applying 490 kPa (5 kgf/cm
2, 71 psi) of compressed
air, check that the solenoid valves do not leak air.
2. When battery positive voltage is supplied to the so-
lenoid valves, check that the solenoid valves open.
Replace solenoid valve.
2Check harness and connector between ECM and solenoid (See page IN±33\
).
Repair or replace harness or connector.
Proceed to next circuit inspection shown on ma-
trix chart (See page AT±66). However, when diag.
trouble code 62 or 63 is displayed, check and re-
place ECM.
AT±92±
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DTC64No. 3 Solenoid Valve Circuit
(For Lock±up Control Pressure Modulation)
CIRCUIT DESCRIPTION
The No. 3 solenoid valve is provided for lock±up operations.
The lock±up operation pressure is controlled by the linear sole-
noid for smooth engagement.
The amount of current flow to the solenoid is controlled by the
duty ratio (See page AT±82) of ECM output signal. The higher
the duty ration becomes, the higher the lock±up hydraulic pres-
sure becomes during the lock±up operation. If the malfunction
occurs in this circuit and diagnostic trouble code 64 is stored in
memory, the O/D OFF indicator light does not blink.
DTC No.DTC Detecting ConditionTrouble Area
64
All conditions below are detected for 1 sec. or more.
2 trip detection logic*
(a) ECM outputs duty signal to No. 3 solenoid in 90%
or higher duty ration.
(b) Current to No. 3 solenoid: 450
100 mA or less.
 No. 3 solenoid valve
 Harness or connector between No. 3 sole-
noid valve and ECM.
 ECM
*: See page AT±62
Reference
 Waveform between terminals SLU± and E
1 when lock±up function is not operated.
Reference
 Waveform between terminals SLU± and E
1 when lock±up function is operated.
AT±94±
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OKNG
2Check harness and connector between battery and No. 4 solenoid valve, No. 4 solenoid valve\
and ECM (See page IN±33).
Repair or replace harness or connector.
Proceed to next circuit inspection shown on ma-
trix chart (See page AT±66). However, when diag.
trouble code 64 is display, check and replace ECM.
±
A304E (1UZ±FE) AUTOMATIC TRANSMISSION TROUBLESHOOTINGAT±97
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NGNG
OKNG
INSPECTION PROCEDURE
1Check resistance between terminals NCO+ and NCO± of ECM connector.
C
OK
PConnect the check harness A to the ECM (See EG sec-
tion).
Check resistance between terminals NCO
+ and NCO±
of ECM connector.
Resistance: 560 ± 680

Proceed to next circuit inspection shown on matrix chart
(See page AT±66). However, when diag. trouble code 67
is displayed, check and replace ECM.
2Check O/D direct clutch speed sensor.
C
OK
Hint
P
OK
C
Remove O/D direct clutch speed sensor from transmis-
sion (See page AT±17).
Measure resistance between terminals 1 and 2 of O/D
direct clutch speed sensor.
Resistance: 560 ± 680

Reference
Check the speed sensor function
Check voltage between terminals 1 and 2 of the speed
sensor when a magnet is put close to the front end of the
speed sensor then taken away quickly.
Voltage is generated intermittently.
The voltage generated is extremely low.
Replace O/D direct clutch speed sensor.
Check and repair harness and connector between
ECM and O/D direct clutch speed sensor (See
page IN±33).
AT±100±
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WIRING DIAGRAM
O/D Main Switch and O/D OFF Indicator Light Circuit
CIRCUIT DESCRIPTION
The O/D main switch contacts go off when the switch is pushed in and comes on when it is pushed out.
In O/D main switch OFF position, the O/D OFF indicator lights up, and the \
ECM prohibits shifting to over-
drive. The ECM also causes the O/D OFF indicator light to blink when a malfunc\
tion is detected. In this
case, connecting the terminals in the DLC2 or DLC1 can display the malfu\
nction code.
DIAGNOSTIC CHARTDIAGNOSTIC CHART
See next page.
AT±112
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O/D OFF indicator light does not light up.
AT±66
BE IN±33
IN±33
O/D OFF indicator light blinks
Perform diagnostic trouble code check (See page AT±38).
±
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