1991 LEXUS SC400 Service Repair Manual

Page 1113 of 4087

LEXUS SC400 1991  Service Repair Manual 
WIRING DIAGRAM
ABS Warning Light Circuit
CIRCUIT DESCRIPTION
If the ECU detects trouble, it lights the ABS warning light while at the s\
ame time prohibiting ABS control.
At this time, the ECU record

Page 1114 of 4087

LEXUS SC400 1991  Service Repair Manual 
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)BR±145 
WhereEverybodyKnowsYourName

Page 1115 of 4087

LEXUS SC400 1991  Service Repair Manual 
OKNG
OKNG
INSPECTION PROCEDURE
1Check ABS warning light.
See Combination Meter Troubleshooting on page BE±159.
Replace bulb or combination meter assembly.
2Check ABS solenoid relay.
C
OK
P
OK
C
Remo

Page 1116 of 4087

LEXUS SC400 1991  Service Repair Manual 
NOYES
YESNO
OKNG
INSPECTION PROCEDURE
3Is diagnosis trouble code output?
Perform diagnostic trouble code check on page BR±76.
Repair circuit indicated by the code output.
4Does ABS warning light go

Page 1117 of 4087

LEXUS SC400 1991  Service Repair Manual 
IN±33).
WIRING DIAGRAM
Tc Terminal Circuit
CIRCUIT DESCRIPTION
Connecting  between terminals Tc  and E1 of the DLC1 or the DLC2 causes the ECU to display the diagnos-
tic trouble code by flashing th

Page 1118 of 4087

LEXUS SC400 1991  Service Repair Manual 
NGOK
OKNG
INSPECTION PROCEDURE
1Check voltage between terminals Tc and E1 of DLC2 or DLC1.
C
OK
PTurn ignition switch ON.
Measure voltage between terminals Tc and E1 of DLC2
or DLC1.
Voltage: 10 ± 1

Page 1119 of 4087

LEXUS SC400 1991  Service Repair Manual 
 IN±33 ).
WIRING DIAGRAM
Ts Terminal Circuit
CIRCUIT DESCRIPTION
The sensor check circuit detects abnormalities in the speed sensor signal w\
hich can not be detected with
the diagnostic trouble cod

Page 1120 of 4087

LEXUS SC400 1991  Service Repair Manual 
NGOK
OKNG
INSPECTION PROCEDURE
1Check voltage between terminal Ts and E1 of data link connector 1.
C
OK
PTurn ignition switch ON.
Measure voltage between terminals Ts and E1 of DLC1.
Voltage: 10 ± 1