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: fuses, clock reset, wheel size, parking brake, key, instrument cluster, engine oil

Page 931 of 4087

LEXUS SC400 1991  Service Repair Manual 
±
BRAKE SYSTEM TRACTION CONTROL SYSTEM (TRAC)BR±185 
WhereEverybodyKnowsYourName

Page 932 of 4087

LEXUS SC400 1991  Service Repair Manual 
WIRING DIAGRAM
IN±33).
DTC24TRAC Sub±Throttle Actuator Circuit
CIRCUIT DESCRIPTION
The sub±throttle actuator operates in accordance with signals from the E\
CU, controlling the opening and
closing

Page 933 of 4087

LEXUS SC400 1991  Service Repair Manual 
OKNG
OKNG
INSPECTION PROCEDURES
1Check TRAC fuse.
C
OK
PRemove TRAC fuse from R/B No. 2.
Check continuity of TRAC fuse.
Continuity
Check for short in all harness and components con-
nected to TRAC fu

Page 934 of 4087

LEXUS SC400 1991  Service Repair Manual 
OKNG
OKNG
3Check sub±throttle actuator.
C
OK
PDisconnect sub±throttle actuator connector.
Check continuity between each terminal of sub±throttle
actuator  connector shown below.
Replace sub±throt

Page 935 of 4087

LEXUS SC400 1991  Service Repair Manual 
WIRING DIAGRAM
DTC25, 26, 27TRAC Sub±Throttle Valve
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
25
The difference between the sub±throttle sensor signal
voltage and the voltage r

Page 936 of 4087

LEXUS SC400 1991  Service Repair Manual 
The speed sensor detects the wheel speed and sends the ap-
propriate  signals to the ECU. These signals are used for control
of both the ABS and TRAC control systems. The front and rear
rotors each h

Page 937 of 4087

LEXUS SC400 1991  Service Repair Manual 
BR±120
WIRING DIAGRAM
DIAGNOSTIC CHARTDIAGNOSTIC CHART
±
BRAKE SYSTEM TRACTION CONTROL SYSTEM (TRAC)BR±191 
WhereEverybodyKnowsYourName

Page 938 of 4087

LEXUS SC400 1991  Service Repair Manual 
IN±33).
WIRING DIAGRAM
DTC41IG Power Source Circuit
CIRCUIT DESCRIPTION
This is the power source for the ECU and becomes power source for the CPU an\
d actuators.
DTC No.DTC Detecting ConditionTroub

Page 939 of 4087

LEXUS SC400 1991  Service Repair Manual 
OKNG
NGOK
OKNG
INSPECTION PROCEDURE
1Check battery positive voltage.
Voltage: 10 ± 14 VCOK
Check and repair the charging system.
2Check voltage between terminals IG and GND of TRAC ECU connector.
C

Page 940 of 4087

LEXUS SC400 1991  Service Repair Manual 
OKNG
4Check ECU±IG fuse.
C
OK
PRemove ECU±IG fuse from J/B No. 1.
Check continuity of ECU±IG fuse.
Continuity
Check for short in all the harness and components con-
nected to ECU±IG fuse (See att
Trending: mirror, Throttle Position sensor, trunk release, wheel torque, ad blue, power steering, sunroof