LEXUS SC400 1991 Service Repair Manual

3. DISCONNECT CABLE FROM NEGATIVE TERMINAL OFBATTERY
CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the ºLOCKº position and the negative (±) termi-
nal cable is disconnected from the battery.
4. INSPECT HEATER RESIST ANCE OF MAIN OXYGEN
SENSORS
(a) Disconnect the oxygen sensor connectors.
(b) Using an ohmmeter, measure the resistance between the terminals +B and HT.
Resistance: 5.1±6.3
at 20 °C (68 °F)
If the resistance is not as specified, replace the sensor.
Torque: 44 N Vm (450 kgf Vcm, 33 ft Vlbf)
(c) Reconnect the oxygen sensor connectors.
5. RECONNECT CABLE TO NEGATIVE TERMINAL OF BATTERY
FI±116
EFI SYSTEM
± Electronic Control System (Main Oxygen Sensors)
WhereEverybodyKnowsYourName

Sub±Oxygen Sensors
COMPONENTS FOR REMOVAL AND
INSTALLATION
FI±117 ± Electronic Control System (Sub±Oxygen\
Sensors)EFI SYSTEM
WhereEverybodyKnowsYourName

INSPECTION OF SUB±OXYGEN
SENSORS
1. INSPECT SUB±OXYGEN SENSORS(a) Cancel diagnostic code. (See TR section)
(b) A llo w th e en g in e to wa rm up to no rma l op e ra tin gtemperature.
(c) Drive for 5 minutes or more between 80km/h (50 mph) and 100 km/h (62 mph) in ºDº range.
(d) Following the conditions in step (c), press fully on the accelerator pedal for 2 seconds or more.
HINT: Do not exceed 100 km/h (62 mph), or diagnostic code
will be cancelled.
(e) Stop the vehicle, and turn the ignition switch to OFF.
(f) Carry out steps (b), (c) and (d) again to test acceleration.
If code No.27 reappears again, check the sub±oxygen sen-
sor circuit. If the circuit is normal, replace the sub±oxygen
sensor.
2. DISCONNECT CABLE FROM NEGATIVE TERMINAL OF BATTERY
CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the ºLOCKº position and the negative (±) termi-
nal cable is disconnected from the battery.
3. REMOVE TRANSMISSION SHIFT LEVER KNOB (a) Push down the lever cover.
(b) Remove the two screws and shift lever knob.
(c) Remove the lever cover.
FI±118
EFI SYSTEM
± Electronic Control System (Sub±Oxygen Sensors)
WhereEverybodyKnowsYourName

4. REMOVE CUP HOLDERUsing a screwdriver, pry out the rear side of the cup holder.
Remove the cup holder.
5. REMOVE UPPER REAR CONSOLE PANEL Using a screwdriver, pry out the console panel.
6. REMOVE UPPER CONSOLE PANEL (a) Remove the six mounting screws.
(b) Using a screwdriver, pry out the console panel.
7. REMOVE RADIO (a) Remove the five mounting bolts.
(b) Disconnect the wiring connectors and antenna cable,
and remove the radio.
8. DISCONNECT SUB±OXYGEN SENSOR CONNECTORS FI±119
EFI SYSTEM
± Electronic Control System (Sub±Oxygen Sensors)
WhereEverybodyKnowsYourName

9. INSPECT HEATER RESISTANCE OF SUB±OXYGEN
SENSORS
Using an ohmmeter, measure the resistance between the ter-
minals +B and HT.
Resistance: 5.1±6.3
at 20 °C (68 °F)
If the resistance is not as specified, replace the sensor as
follows:
w Disconnect the grommet from the floor panel, and
pull out the wire of the sub±oxygen sensor from the
floor panel.
w Remove the sub±oxygen sensor.
w Install a new sub±oxygen sensor.
Torque: 44 N Vm (450 kgf Vcm, 33 ft Vlbf)
w Run the wire of the sub±oxygen sensor through the
hole in the floor panel.
10. RECONNECT SUB±OXYGEN SENSOR CONNECTORS
11. REINSTALL RADIO (a) Connect the wiring connectors and antenna cable.
(b) Install the radio with the five bolts.
12. REINSTALL UPPER REAR CONSOLE PANEL (a) Fit the console panel to the console box with five clips.
(b) Install the console panel with the six screws.
FI±120
EFI SYSTEM
± Electronic Control System (Sub±Oxygen Sensors)
WhereEverybodyKnowsYourName

13. REINSTALL UPPER CONSOLE PANELFit the console panel to the console box with the four clips.
14. REINSTALL CUP HOLDER Fit the cup holder to the console box.
15. REINSTALL TRANSMISSION SHIFT LEVER KNOB (a) Slide the lever cover on the lever shaft.
(b) Install the shift lever knob with the two screws.
(c) Attach the l ever cover to the lower side of the lever knob.
16. RECONNECT CABLE TO NEGATIVE TERMINAL OF BATTERY FI±121
EFI SYSTEM
± Electronic Control System (Sub±Oxygen Sensors)
WhereEverybodyKnowsYourName

Preparation
SST (SPECIAL SERVICE TOOLS)
IllustrationPart No.Part NameNote
09268±41045Injection Measuring
Tool Set
(90268±41070)No. 4 Union
Injector
(09268±41080)No. 6 Union
Cold start Injector
(09268±52010)Injection Measuring
Attachment
Injector
09268±45012EFI Fuel Pressure
Gauge
09612±24014
Steering Gear
Housing Overhaul
Tool Set
(09617±24011)Steering Rack Wrench
Fuel pressure pulsation damper
09631±22020
Power Steering
Hose Nut 14 X 17 mm
Wrench SetFuel line flare nut
09816±30010Oil Pressure
Switch SocketKnock sensor
09842±30055Wire ªGº
EFI Inspection
Cold start Injector
09842±30070Wire ªFº
EFI Inspection
Injector
09843±18020Diagnosis Check
Wire
0990±01000
Engine Control
Computer
Check Harness ªAº
FI±10 ± PreparationEFI SYSTEM
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RECOMMENDED TOOLS
IllustrationPart No.Part NameNote
09082±0015TOYOTA
Electrical Tester
09200±00010Engine Adjust
Kit
09258±00030Hose Plug Set
Plug for the Vacuum hose, fuel hose ect.
EQUIPMENT
Part NameNote
Graduated cylinderInjector
Tachometer
Torque wrench
SSM (SERVICE SPECIAL MATERIALS)
Part NamePart No.Use etc.
Seal packing 1282B,08826±00100Water inlet housing
Three bond 1282B or equivalent
FI±11EFI SYSTEM ± Preparation
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Fuel pump ECU
COMPONENTS FOR REMOVAL AND
INSTALLATION
FI±122 ± Electronic Contro\
l System (Fuel Pump ECU)EFI SYSTEM
WhereEverybodyKnowsYourName

INSPECTION OF FUEL PUMP ECU
1. DISCONNECT CABLE FROM NEGATIVE TERMINAL OFBATTERY
CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the ºLOCKº position and the negative (±) termi-
nal cable is disconnected from the battery.
2. REMOVE SEAT CUSHION AND BACK
3. REMOVE QUARTER TRIM
(a) Disconnect the rear side of the scuff plate by pulling it.
(b) Remove clip A.
(c) Remove the belt hole cover by pulling it.
(d) Remove clip B.
(e) Remove the quarter trim by pulling it.
4. DISCONNECT FUEL PUMP ECU CONNECTOR FI±123
EFI SYSTEM
± Electronic Control System (Fuel Pump ECU)
WhereEverybodyKnowsYourName