1991 LEXUS SC400 sensor

SR±52).
IN±33).
WIRING DIAGRAM
Tilt Position Sensor Circuit
CIRCUIT DESCRIPTION
The tilt position is sent to the ECU as a voltage signal from the position \
sensor.
A constant 5 V is supplied to terminal 1 of sensor.
The voltage at terminal 3 varies with position and is input to the ECU.
DIAGNOSTIC CHARTDIAGNOSTIC CHART
SR±72±
STEERING STEERING COLUMN
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NGOK
OKNG
OKNG
INSPECTION PROCEDURE
1Check voltage between terminals TiS and E1 of ECU connector.
C
OK
Hint
P1. Remove ECU with connectors still connected.
2. Remove tilt sensor with connector still connected.
Measure voltage between terminals TiS and E
1 of ECU
connector, while turning tilt sensor lever slowly by hand
from raised side to lowered side.
Voltage:
Fully raised: Below 1 V
Fully lowered: 4 ± 6 V
In addition, as the lever is turned, the voltage should
increase gradually without interruption.
Proceed to next circuit inspection shown on matrix chart
(See page SR±52).
2Check tilt position sensor.
C
OK
Hint
PDisconnect tilt sensor connector.
Measure resistance between terminals 1 and 2 of tilt
sensor connector.
Resistance: 4 ± 6

Measure resistance between terminals 3 and 2 of tilt
sensor connector, while turning tilt sensor lever slowly
by hand from raised side to lowered side.
Resistance:
Fully raised: Below 100

Fully lowered: 4 ± 6

In addition, as the lever is turned, the resistance
should increase gradually without interruption.
Replace tilt position sensor.
3Check harness and connectors between ECU and tilt position sensor (See \
page IN±33).
Repair harness or connector.
Check and replace ECU.
±
STEERING STEERING COLUMNSR±73
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SR±52).
IN±33).
WIRING DIAGRAM
Telescopic Position Sensor Circuit
CIRCUIT DESCRIPTION
The telescopic position is sent to the ECU as a voltage signal from the pos\
ition sensor.
A constant 5 V is supplied to terminal 6 of the sensor.
The voltage at terminal 5 varies with position and is input to the ECU.
DIAGNOSTIC CHARTDIAGNOSTIC CHART
SR±76±
STEERING STEERING COLUMN
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NGOK
OKNG
OKNG
INSPECTION PROCEDURE
1Check voltage between terminals TeS and E1 of ECU connector.
C
OK
P1. Remove ECU with connectors still connected.
2. Remove telescopic sensor with connectors stillconnected.
Measure voltage between terminals TeS and E
1 of ECU
connector while turning telescopic sensor lever slowly
by hand from Contracted side to Extended side.
Voltage:
Fully forward: 0 ± 1 V
Fully back: 4 ± 5 V
In addition, as the lever is turned, the voltage should
increase gradually without interruption.
Proceed to next circuit inspection shown on matrix chart
(See page SR±52).
2Check telescopic position sensor.
C
OK
P
OK
C
Disconnect telescopic sensor connector.
Measure resistance between terminals 3 and 6 of tele-
scopic sensor connector.
Resistance: Approx. 5 k

Measure resistance between terminals 3 and 5 of tele-
scopic sensor connector while turning telescopic lever
slowly by hand from Contracted side to Extended side.
Resistance:
Fully forward: 0 ± 1

Fully back: 4 ± 5

In addition, as the lever is turned, the resistance
should increase gradually without interruption.
Replace tilt position sensor.
3Check harness and connectors between ECU and tilt position sensor (See \
page IN±33).
Repair harness or connector.
Check and replace ECU.
±
STEERING STEERING COLUMNSR±77
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TORQUE SPECIFICATIONS
SR0GQ±01\
 \
Part tightened NVm kgf Vcm ft Vlbf\
 \
STEERING COLUMN   
\
 \
Steering wheel 35 360 26\
 \
Steering wheel pad 7.4 75 65 in. Vlbf\
 \
Column bracket X Body 25 260 19\
 \
Sliding yoke 35 360 26\
 \
(Power tilt and power telescopic steering column)   
\
 \
Tilt steering housing support X Lower tube 13 130 9\
 \
Support stopper bolt lock nut 2.9 30 26 in. Vlbf\
 \
Connector bracket 4.9 50 43 in. Vlbf\
 \
Telescopic sensor plate 4.9 50 43 in. Vlbf\
 \
Telescopic adjusting screw 6.9 70 61 in. Vlbf\
 \
Telescopic adjusting screw lock nut 31 320 23\
 \
(Manual tilt and Manual telescopic steering column)   
\
 \
Tilt memory bolt 6.4 65 56 in. Vlbf\
 \
Tilt memory bolt set nut 5.9 60 52 in. Vlbf\
 \
Tilt lever assembly installation bolt 2.9 30 26 in. Vlbf\
 \
Tilt pawl set nut 5.9 60 52 in. Vlbf\
 \
Tilt lever retainer set nut 15 150 11\
 \
Compression spring bushing bolt 7.8 80 69 in. Vlbf\
 \
Steering column tube stopper bolt 19 195 14\
 \
Serration attachment set nut 13 130 9\
 \
Telescopic lever set bolt 25 260 19\
 \
Connector bracket set bolt 4.9 50 43 in. Vlbf\
 \
POWER STEERING PUMP   
\
 \
(SC 400)   
\
 \
PS pump installation bolt 39 400 29\
 \
PS pump installation nut 43 440 32\
 \
Pressure tube X Pressure port union 49 500 36\
 \
Drive pulley X Rotor shaft 43 440 32\
 \
Front housing X Rear bracket 39 400 29\
 \
Pressure port union X Pump housing 69 700 51\
 \
Suction port union X Pump housing 13 130 9\
 \
(SC 300)   
\
 \
PS pump installation bolt 58 590 43\
 \
Pressure tube X Pressure port union 49 500 36\
 \
Drive pulley X Rotor shaft 43 440 32\
 \
Front housing X Rear housing 17 170 12\
 \
Pressure port union X Pump housing 83 850 61\
 \
Reservoir tank X Pump housing Front side bolt 13 130 9\
 \
Rear side bolts 17 170 12
±
STEERING SERVICE SPECIFICATIONSSR±171
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STEERING COLUMN
DESCRIPTION
SR0EA±02
There are two types of steering column, the manual tilt/manual telescopic one\
, and the power tilt/power
telescopic one.
SR0EB±02
OPERATION
POWER TILT OPERATIONThe power tilt mechanism consists of the control gear assembly, tilt motor, tilt position sensor, tilt and tele-
scopic switch, unlock warning switch and tilt and telescopic ECU.
The control gear assembly consists of the worm wheel, tilt gear, tilt worm and slider. Rotation of the tilt motor
moves the slider towards the tilt worm. The column upper tube is integrated w\
ith the slider and is rotated
up and down by movement of the slider.
SR±4
±
STEERING STEERING COLUMN
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POWER TELESCOPIC OPERATION
SR0EC±02
The power telescopic mechanism is composed of the control gear assembly, telescopic motor, telescopic
position sensor, tilt and telescopic switch, unlock warning switch and tilt and telesco\
pic ECU.
The control gear assembly is composed of the worm wheel, telescopic scre\
w and slider. Rotation of the
telescopic motor moves the slider in the direction of the telescopic screw axis. The\
sliding tube is integrated
with the slider and is moved forward and backward by movement of the slider.
±
STEERING STEERING COLUMNSR±5
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STEERING COLUMN DISASSEMBLY
SR0EL±04
NOTICE: When placing the breakaway bracket in a vise during
disassembly or assembly of the steering column, use alumi-
num, etc. to prevent scratches to the tip of the capsule.
1. REMOVE IGNITION KEY CYLINDER ILLUMINATION
2. REMOVE SLIDING YOKE Place matchmarks on the sliding yoke and main shaft.
3. REMOVE LOWER DUST COVER
(a) Remove the clip and dust cover.
(b) Using a screwdriver, remove the dust seal.
4. REMOVE TELESCOPIC POSITION SENSOR PLATE
5. REMOVE TILT AND TELESCOPIC POSITION SENSORS
±
STEERING STEERING COLUMNSR±29
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