LEXUS SC400 1991 Service Repair Manual

SSM (SPECIAL SERVICE MATERIALS)
SA095±04\
 
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08826±00110 Seal packing 1389,
THREE BOND 1389 or equivalent 






Differential Carrier x Cover
\
 
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08833±00100 THREE BOND 1360K or equivalentDifferential Case x Ring Gear
LUBRICANT
SA096±02
 Item Capacity Classification
 








Differential oil
 








1.35 liters (1.43 US qts, 1.19 lmp. qts)
 








API GL±5 Hypoid Gear Oil
[Above±18

C (0
F)]
SAE 90
[Below±18
C (0
F)]
SAE 80W or 80W±90
SA±78±
SUSPENSION AND AXLE REAR DIFFERENTIAL
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ON±VEHICLE REPAIR
COMPONENTS
SA097±02
SIDE GEAR SHAFT OIL SEAL
REPLACEMENT
SA0V1±04
1. DRAIN DIFFERENTIAL OIL
2. REMOVE REAR DRIVE SHAFT(See page SA±65)
3. REMOVE SIDE GEAR SHAFT
(a) Using SST and 2 bolts, remove the side gear shaft. SST 09520±22010
(b) Remove the snap ring from the side gear shaft.
4. REMOVE SIDE GEAR SHAFT OIL SEAL Using SST, remove the oil seal.
SST 09308±00010
±
SUSPENSION AND AXLE REAR DIFFERENTIALSA±79
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5. INSTALL SIDE GEAR SHAFT OIL SEAL
(a) Using SST and a hammer, drive in a new oil seal.SST 09608±32010, 09608±35014 (09608±06020)
(b) Apply MP grease to the oil seal lip.
6. INSTALL SIDE GEAR SHAFT
(a) Install a new snap ring to the side gear shaft.
(b) Using a hammer and brass bar, tap in the side gear shaft to
the differential.
NOTICE: Be careful not damage the side gear shaft and oil
seal.
7. CHECK INSTALLATION OF SIDE GEAR SHAFT
(a) Check that there is 2±3 mm (0.08±0.12 in.) of play in axialdirection.
(b) Check that the side gear shaft will not come out by trying to pull it out by hand.
8. INSTALL REAR DRIVE SHAFT
(See page SA±65)
9. CHECK DIFFERENTIAL OIL LEVEL Fill with hypoid gear oil if necessary.
Oil grade:
API GL±5 Hypoid Gear Oil
Viscosity: Above±18
C (0
F) SAE 90
Below±18
C (0
F) SAE 80W±90 or 80W
Capacity: 1.35 liters (1.43 US qts, 1.19 lmp. qts)
SA±80±
SUSPENSION AND AXLE REAR DIFFERENTIAL
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ECU Power Source Circuit
CIRCUIT DESCRIPTION
When the ignition switch is turned on, battery voltage
is applied to the terminal IG SW of the ECU, and the
main relay control circuit in the ECU sends a signal to
the terminal M±REL of the ECU, switching on the
main relay. This signal causes current to flow to the
coil, closing the contacts of the main relay and supply-
ing power to the terminals +B and +B1 of the ECU.
If the ignition switch is turned off, the ECU continues
to switch on the main relay for a maximum of 2 se-
conds for the initial setting of the ISC valve.
DIAGNOSTIC CHARTDIAGNOSTIC CHART
See next page for the DIAGNOSTIC CHART.
WIRING DIAGRAM
TR±124±
ENGINE TROUBLESHOOTING Circuit Inspection
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DIAGNOSTIC CHART
DIAGNOSTIC
CHART
Check for short in all the harness and
components connected to IGN fuse.
Check voltage of terminal M±REL.
Check for open in harness and connector
between battery and ECU.
Check and replace ECU.
Replace ignition switch.
Repair or replace harness or
connector.
Repair or replace harness or
connector.
Check for open and short in harness and
connector between terminal M REL and body
ground.
Replace EFT main relay.
Check voltage of terminal IGSW.
Check IGN fuse.
Check continuity between terminals E1 and
body ground.
Check voltage of ECU power source.
Proceed to next circuit inspection
shown on matrix chart (See page
TR±35
).
Check ignition switch.
Check EFT fuse.
Check EFT main relay.
Check and repair or harness or connector
between EFI fuse and battery.
Check for short in all the harness and
components connected to EFI fuse.
±
ENGINE TROUBLESHOOTING Circuit InspectionTR±125
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NGOK
OKNG
NGOK
INSPECTION PROCEDURE
1Check voltage between terminals + B, + B1 and E1 of engine & ECT ECU connecto\
r.
C
OK
P(2) Connect the Check Harness A.(See page TR±30)
(2) Turn ignition switch on.
Measure voltage between terminals + B, + B1 and E1
of engine & ECT ECU connector.
Voltage: 10 ± 14 V
Proceed to next circuit inspection shown on matrix chart
2Check for open in harness and connector between terminals E1 of engine &\
ECT ECU and body
ground (See page IN±27).
Repair or replace harness or connector.
3Check voltage between terminal IG SW of engine & ECT ECU connector and b\
ody ground.
C
OK
PTurn ignition switch on.
Measure voltage between terminal IG SW of engine &
ECT ECU connector and body ground.
Voltage: 10 ± 14 V
Go to step 6.
TR±126
±
ENGINE TROUBLESHOOTING Circuit Inspection
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OKNG
OKNG
4Check IGN Fuse.
C
OK
PRemove IGN fuse from J/B No.1.
Check continuity of IGN fuse.
Continuity.
Check for short in all the harness and components con-
nected to IGN fuse (See attached wiring diagram).
5Check ignition switch.
C
OK
PRemove under cover and finish panel.
Check continuity between terminals.
continuity
Replace ignition switch.
Check and repair harness and connector between
battery and ignition switch, ignition switch and en-
gine & ECT ECU.
±
ENGINE TROUBLESHOOTING Circuit InspectionTR±127
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OKNG
OKNG
6Check voltage between terminal M±REL of engine & ECT ECU connector and bod\
y ground.
C
OK
PTurn ignition switch on.
Measure voltage between terminal M±REL of engine &
ECT ECU connection and body ground.
Voltage: 10 ± 14 V
Check and replace engine & ECT ECU.
7Check EFI
C
OK
PRemove EFI fuse R/B No.2.
Check continuity of EFI fuse.
Continuity
Rep
TR±128
±
ENGINE TROUBLESHOOTING Circuit Inspection
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OKNG
OKNG
8Check EFI main relay.
C
OK
P
C
OK
Remove EFI main relay.
Check continuity between terminals of EFI main relay
shown below.
(2) Apply battery voltage between terminals 1 and 3.
(2) Check continuity between terminals 2 and 4.
Replace EFI main relay.
9Check for open and short in harness and connector between terminal M±REL o\
f engine & ECT
ECU and body ground (See page IN±27).
Repair or replace harness or connector.
Check and repair harness or connector between
EFI fuse and battery.
±
ENGINE TROUBLESHOOTING Circuit InspectionTR±129
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Check EFI fuse.
Check voltage of terminal BATT.
Check operation for the back±up.
Proceed to next circuit inspection
shown on matrix chart (See page TR±39).
Check for short in all the harness and
components connected to EFI fuse.
Check and repair harness or connector
between battery, EFI fuse and ECU.
Check and replace fuse.
WIRING DIAGRAM
Back Up Power Source Circuit
CIRCUIT DESCRIPTION
Battery voltage is supplied to terminal BATT of the ECU even when the ignition switch is off for use
by the diagnostic code memory and air±fuel ratio adaptive control val\
ue memory, etc.
DIAGNOSTIC CHART
TR±126±
ENGINE TROUBLESHOOTING Circuit Inspection
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