LEXUS SC400 1991 Service Repair Manual

LEXUS SC400 1991 Service Repair Manual SC400 1991 LEXUS LEXUS https://www.carmanualsonline.info/img/36/57051/w960_57051-0.png LEXUS SC400 1991 Service Repair Manual
Trending: differential, lumbar support, horn, wheel bolts, seat memory, relay, flat tire

Page 191 of 4087

LEXUS SC400 1991  Service Repair Manual 
OKNG
1
2
3
4
5
6
6
OK
OK
YES
YES NG
NG NO
NO
Check connection of center airbag sensor
assembly connector.
Preparation.
Check airbag warning light circuit.
Does airbag warning light come on?
Is new EC

Page 192 of 4087

LEXUS SC400 1991  Service Repair Manual 
YESNO
1
Replace center airbag sensor assembly. Using simulation method,
reproduce malfunction symptoms
(See page 
IN±20).
WIRING DIAGRAM
Is diagnostic code 22 output again?
      DIAGNOSTIC CHART
HI

Page 193 of 4087

LEXUS SC400 1991  Service Repair Manual 
Check ECU±B fuse.
NG
OK
1
6Go to step
(1) Disconnect battery negative (±) terminal cable, and wait at least 20 seconds.
(2) Remove steering wheel pad (See page  AB±14).
When storing steering wheel

Page 194 of 4087

LEXUS SC400 1991  Service Repair Manual 
4
5
6
Check terminal LA of center airbag sensor assem-
bly and electrical connection check mechanism.
If normal, replace center airbag sensor assembly.
NG
OK
(1) Disconnect negative (±) terminal cab

Page 195 of 4087

LEXUS SC400 1991  Service Repair Manual 
1
Using simulation method, reproduce malfunction
symptoms (See page IN±20).NO
YES
(1) Turn ignition switch LOCK, and wait at least 2
seconds.
(2) Turn ignition switch ACC or ON, and wait at least 20

Page 196 of 4087

LEXUS SC400 1991  Service Repair Manual 
YES
Is diagnostic code 31 output again?
NO
1
Replace center airbag sensor assembly. Using simulation method, reproduce
malfunction symptoms
(See page 
IN±20).
Diag. Code 31Center Airbag Sensor Assem

Page 197 of 4087

LEXUS SC400 1991  Service Repair Manual 
1
NG
OK
(1) Turn ignition switch LOCK, and wait at least 20 
seconds.
(2) Turn ignition switch ACC or ON, and wait at least 20 seconds.
(3) Repeat operation in step (1) and (2) at least 5 times.
(4)

Page 198 of 4087

LEXUS SC400 1991  Service Repair Manual 
OK
Check operation of airbag warning light.
NG1
WIRING DIAGRAM
2Is diagnostic code 41 output again? System is normal.
Check harness between ECU±B
fuse and center airbag sensor as-
sembly. If normal,

Page 199 of 4087

LEXUS SC400 1991  Service Repair Manual 
Clear malfunction code 41 stored in memory
(See page AB±32).
Check operation of airbag warning light.
NG
OK
1
Airbag warning light turns off.
(1) Turn ignition switch LOCK, and wait at least 
2 seco

Page 200 of 4087

LEXUS SC400 1991  Service Repair Manual 
YES
Does airbag warning light turn off?
NO
1
Replace center airbag sensor assembly. Check airbag warning light circuit
or terminal AB circuit of TDCL or
check connector.
WIRING DIAGRAM
Airbag Warning
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