ignition LEXUS SC300 1991 Service Repair Manual

(b) Install the lower dust cover and clip.
24. INSTALL SLIDING YOKEAlign matchmarks and install the sliding yoke to the main
shaft.
Torque: 35 N Vm (360 kgf Vcm, 26 ft Vlbf)
25. INSTALL IGNITION KEY CYLINDER ILLUMINATION
26. CHECK TILT OPERATION
(a) Check that there is not axial play at the end of the main shaft.
(b) With the main shaft in the neutral position, push the tilt lever and check that the main shaft rises to the uppermost position.
(c) Lower the main shaft, and check that it locks in the uppermost position.
27. CHECK TELESCOPIC OPERATION
(a) Check that t here is no axial play when the lever is turned fully
counterclockwise.
(b) Check that the main shaft moves smoothly when the lever is turned clockwise.
SR±26
±
STEERING STEERING COLUMN
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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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2. IF NECESSARY, REPLACE KEY CYLINDER
(a) Place the ignition key at the ACC position.
(b) Push down the stop pin with a thin rod, and pull out the keycylinder.
(d) Install a new key cylinder. HINT: Make sure the ignition key is at the ACC position.
3. INSPECT UPPER BEARING Check the upper bearing rotation condition and check for ab-
normal noise.
If the bearing is worn or damaged, replace the column upper
tube.
4. IF NECESSARY, ADJUST TELESCOPIC ADJUSTING SCREWS
(a) Using SST, remove the lock nuts.
SST 09617±14010
(b) Using SST, tighten the adjusting screws. SST 09923±00010
Torque: 6.9 N Vm (70 kgf Vcm, 64 in. Vlbf)
NOTICE:
w If the adjusting screw is tightened higher than the
specified torque, the telescopic mechanism may
malfunction. Conversely, if the torque applied is too low,
rattling may develop in the column, so the specified
torque should always be applied.
w When the adjusting screw and conical springs have been
removed, replace the conical springs facing in the
direction shown in the illustration.
±
STEERING STEERING COLUMNSR±33
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11. INSTALL TELESCOPIC SENSOR PLATE
Torque: 4.9 NVm (50 kgf Vcm, 43 in. Vlbf)
12. INSTALL LOWER DUST COVER
(a) Using a press, install the dust seal.
(b) Install the lower dust cover and clip.
13. INSTALL SLIDING YOKE
Align matchmarks and install the sliding yoke to the main
shaft.
Torque: 35 N Vm (360 kgf Vcm, 26 ft Vlbf)
14. INSTALL IGNITION KEY CYLINDER ILLUMINATION
±
STEERING STEERING COLUMNSR±37
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TERMINAL OF ECU
TILT & TELESCOPIC ECU
 




Terminal
No.
 




Symbol
 




Terminal Name
 




Terminal
No.
 




Symbol
 




Terminal Name
 T9±1 Si Serial In T9±16 MSW Manual Switch
 2 DSW Door Courtesy Switch 17 Vc Sensor Power Source
 3 M1 Return Switch 1 18 ECU±B Power Source 

4
 

ASW
 

Auto Switch
 

T10± 1
 

IG
 

Ignition Switch
 5 E1 Sensor Ground 2 Te M+ Telescopic Contracted
 6 Te S Telescopic Sensor 3 TiM± Tilt Down
 
7 
TiS 
Tilt Sensor 
4 
+B 
Power Source 

8
 

ECU±E
 

Ground
 

6
 

P
 

Park/Neutral Position Switch
 9 So Serial Out 6 P Parking Brake Switch*
 10 UWSW Unlock Warning Switch 7 GND Ground 

11 

MRY 

Memory Switch 

10 

TiM+ 

Tilt Up
 12 M2 Return Switch 2 11 TiM± Telescopic Extended
*
SC300 (M/T) Models
SR±48
±
STEERING STEERING COLUMN
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STANDARD VALUE OF ECU TERMINAL
 

Terminals
 

Symbols
 

Wiring
Color 

Condition
 

Standard
Value
 

T9±1 

Si 

B 


Tilt & telescopic ECU & power seat ECU
communication 

0 V
e12 V
 T9±2 e DSW e R±Be Driver's door open Below 1 V
 
T9 2 e
Body Ground 
DSW e
Body Ground 
RBe
Body GroundDriver's door closed1014 V
 T9±3 eT9±8 M1 eECU±E Pe BR±B Driving position memory & return switch ON Below 1 V
 T9±3eT9±8 M1eECU±E PeBR±B Driving position memory & return switch OFF 10
~ 14 V
 T9±4
eT9±5 ASW eE1 V±W eBR Unlock warning switch ON, auto switch ON 10 ~ 14 V
 T9±4eT9±5 ASWeE1 V±WeBR Unlock warning switch ON, auto switch OFF Below 1 V
 T9±5 E1 BR Always Below 1 V
 

T9±6
eT9±5
 

Te S
eE1
 

Y±R
eBR
 


Unlock warning switch ON, telescopic fully
forward 

Below 2 V
 
T9±6eT9±5
 
TeSeE1
 
Y±ReBR
 Unlock warning switch ON, telescopic fully
backward 4±6 V
 
T9±7
eT9±5
 
TiS eE1
 
P±L eBR
 Unlock warning switch ON, tilt fully raised Below 2 V T9±7eT9±5 TiSeE1 P±LeBR Unlock warning switch ON, tilt fully lowered 4±6 V T9±8 ECU±E BR±B Always Below 1 V 

T9±9
 

So
 

W
 

Tilt & telescopic ECU & power seat ECU
communication 

0 V
e12 V
 T9±10 e UWSW e Ye Ignition key inserted in the key cylinder Below 1 V
 T9 10 e
Body Ground UWSW e
Body Ground Ye
Body Ground Ignition key pulled out from the key cylinder 10
~ 14 V
 
T9±11 eT9±8
 
MRY eECU±E
 
R±Y eBR±B
 Auto set switch ON Below 1 V
 T9±11eT9±8 MRYeECU±E R±YeBR±B Auto set switch OFF 10 ~ 14 V
 
T9±12 eT9±8
 
M2 eECU±E
 
P±B eBR±B
 Driving position memory & return switch ON Below 1 V
 T9±12eT9±8 M2eECU±E P±BeBR±B Driving position memory & return switch OFF 10 ~ 14 V
 


 


 


 


Unlock warning switch ON
Telescopic extend by manual switch 

2.6 V
 


 


 


 


Unlock warning switch ON
Tilt up by manual switch 

3.5 V
 T9±16
eT9±17 MSW eVC V±Y eR±W Unlock warning switch ON
Telescopic contracted by manual switch 4.2 V
 


 


 


 

Unlock warning switch ON
Tilt down by manual switch 

4.6 V
 


 


 


 


Unlock warning switch ON, manual switch
OFF 

4±6 V
±
STEERING STEERING COLUMNSR±49
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STANDARD VALUE OF ECU TERMINAL
 

Terminals
 

Symbols
 


Wiring
Color 

Condition
 


Standard
Value
 T9±17 eT9±5 Vc eE1 R±W eBR Unlock warning switch ON 4±6 V
 T9±17eT9±5 VceE1 R±WeBR Unlock warning switch OFF Below 1 V
 T9±18 ECU±B R Always 10 ~ 14 V
 T10±1 e IGe B±R e Ignition switch ON 10 ~ 14 V
 
T10 1 e
Body Ground 
IGe
Body Ground 
BR e
Body Ground Ignition switch OFF Below 1 V
 

T10±2
e
Body Ground
 

Te M+e
Body Ground
 

L±B
e
Body Ground
 


Unlock warning switch ON, telescopic
forward 

10 ~ 14 V
 Body Ground Body Ground Body Ground Except above mention Below 1 V
 T10±3
e TiM±e R±Le Unlock warning switch ON, tilt down 10 ~ 14 V
 
T10 3 e
Body Ground 
TiMe
Body Ground 
RLe
Body Ground Except above mention Below 1 V
 T10±4 +B L±W Always 10 ~ 14 V
 T10±6 e Pe GR e Ignition switch ON, shift lever ªPº position 10 ~ 14 V
 
T10 6 e
Body Ground 
Pe
Body Ground 
GR e
Body Ground Ignition switch ON, except above mention Below 1 V
 T10±6 e Pe GR e Ignition switch ON, PKB lever pulled Below 1 V
 
T10 6 e
Body Ground 
Pe
Body Ground 
GR e
Body Ground Ignition switch ON, PKB lever released 10 ~ 14 V
 T10±7 GND W±B Always Below 1 V
 T10±10 e TiM+e R±Be Unlock warning switch ON, tilt up 10 ~ 14 V
 
T10 10 e
Body Ground 
TiMe
Body Ground 
RBe
Body Ground Except above mention Below 1 V
 T10±11 e
Body Ground
 Te M±e
Body Ground
 L±Ye
Body Ground
 Unlock warning switch ON, telescopic
backward 10 ~ 14 V
 Body Ground Body Ground Body Ground Except above mention Below 1 V
TILT & TELESCOPIC ECU
SR±50±
STEERING STEERING COLUMN
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SR±52).
IN±33).
WIRING DIAGRAM
CIRCUIT INSPECTION
ECU Power Source Circuit
CIRCUIT DESCRIPTION
The ECU power source also supplies power to the CPU and sensor, etc. Power is supplied to the ECU even
when the ignition switch is off.
DIAGNOSTIC CHARTDIAGNOSTIC CHART
SR±62±
STEERING STEERING COLUMN
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OKNG
OKNG
3Check center airbag sensor assembly.
C
OK
Hint
P1. Connect negative (±) terminal cable to battery.
2. Clear malfunction code stored in memory. (Seepage RS±63 ).
1. Turn ignition switch LOCK, and wait at least 20 sec- onds.
2. Using a service wire, connect D
+ and D±, P+ and P±.
3. Turn ignition switch ACC or ON, and wait at least 20 seconds.
4. Using SST, connect terminals Tc and E
1 of DLC2.
SSt 09843±18020
5. Check diagnostic trouble code.
Diagnostic trouble code 53 is not output.
Codes other t han code 53 may be output at this time, but
this is not relevant to this check.
Replace center airbag sensor assembly.
4Check P squib.
C
OK
Hint
P1. Turn ignition switch LOCK.
2. Disconnect battery negative (±) terminal cable, and
wait at least 90 seconds.
3. Connect front passenger airbag assembly connec- tor.
4. Connect negative (±) terminal cable to battery.
5. Clear malfunction code.
1. Turn ignition switch LOCK, and wait at least 20 sec- onds.
2. Turn ignition switch ACC or ON, and wait at least 20 seconds.
3. Using SST, connect terminals Tc and E
1 of DLC2.
SST 09843±18020
4. Check diagnostic trouble code.
Diagnostic trouble code 53 is not output.
Codes other t han code 53 may be output at this time, but
this is not relevant to this check.
Replace front passenger airbag assembly.
±
SUPPLEMENTAL RESTRAINT SYSTEM TROUBLESHOOTINGRS±113
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OKNG
OKNG
3Check center airbag sensor assembly.
C
OK
Hint
P1. Connect connector to center airbag sensor connec-
tor.
2. Connect connector between center airbag sensor assembly and wiring harness connector.
3. Using a service wire, connect D
+ and D±, P+ and P±.
4. Connect negative (±) terminal cable to battery, and wait at least 2 seconds.
1. Turn ignition switch ACC or ON and wait at least 20 seconds. Clear malfunction code. Turn ignition
switch LOCK and wait at least 20 seconds.
2. Turn ignition switch ACC or ON , and wait at least 20 seconds.
3. Using SST, connect terminals Tc and E
1 of DLC2.
SST 09843±18020
4. Check diagnostic trouble code.
Diagnostic trouble code 54 is not output.
Codes other t han code 54 may be output at this time, but
this is not relevant to this check.
Replace center airbag sensor assembly.
4Check P squib.
C
OK
Hint
P1. Turn ignition switch LOCK.
2. Disconnect battery negative (±) terminal cable, and
wait at least 90 seconds.
3. Connect front passenger airbag assembly connec- tor.
4. Connect negative (±) terminal cable to battery, and wait at least 2 seconds.
1. Turn ignition switch ACC or ON and wait at least 20 seconds. Clear malfunction code. Turn ignition
switch LOCK and wait at least 20 seconds.
2. Turn ignition switch ACC or ON, and wait at least 20
seconds.
3. Using SST, connect terminals Tc and E
1 of DLC2.
SST 09843±18020
4. Check diagnostic trouble code.
Diagnostic trouble code 54 is not output.
Codes other t han code 54 may be output at this time, but
this is not relevant to this check.
Replace front passenger airbag assembly.
From the results of the above inspection, the malfunctioning part can now be\
considered normal. To
make sure of this, use the simulation method to check.
RS±118±
SUPPLEMENTAL RESTRAINT SYSTEM TROUBLESHOOTING
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