1991 LEXUS SC400 check engine light

ConnectionCheck forTester connectionConditionSpecified value
Turn signalHazard warning switch ONBattery positiveTurn signal
SW andB 16 Ground
Hazard warning switch ONBattery ositive
voltage e 0V
HazardB±16±Ground
IG SW ON and turn signal SW ºLeftºBattery positive
Warning
Si hVoltage
IG SW ON and turn signal SW ºLeftºBattery ositive
voltage e 0V
SwitchVoltage
Hazard warning switch ONBattery positive
B 17 Ground
Hazard warning switch ONBattery ositive
voltage e 0VB±17±Ground
IG SW ON and turn signal SW ºRightºBattery positiveIG SW ON and turn signal SW ºRightºBattery ositive
voltage e 0V
HeadlightLi ht t l SWDimmer SW ºHIº orBattery positiveHeadlight
VoltageB7±GroundLight control SW
ºHEADº
Dimmer SW HI or
ºFlashº
Battery ositive
voltageVoltageB7±GroundºHEADºDimmer SW ºLOºNo voltage
ContinuityB6±GroundLight control SW
º
HEADº
Dimmer SW ºHIº or
ºFlashºContinuityContinuityB6 GroundºHEADºDimmer SW ºLOºNo continuity
IgniterVoltageA9±GroundEngine RunningVoltage
fluctuates
ECT patternVoltageB4 GroundIG SW ON and ECT patternPWRBattery positive voltageECT attern
Select switchVoltageB4±GroundIG SW ON and ECT attern
select SW positionNORMNo voltage
Engine oilOil temperature below approx. 55 5C (131 5F)Continuityg
Level warn-
ing Switch
ContinuityB8±Ground
Oil temperature
above approx. 55 5CON (float up)ContinuitygContinuityB8 Groundabove a rox. 55 C
(131 5F) and SW
positionOFF (float off)No continuity
GAUGE fuseVoltageA1 GroundIgnition switchONBattery positive voltageVoltageA1±GroundIgnition switch
positionLOCK, ACC, STARTNo voltage
Neutral StartVoltageA12±GroundIgnition switch
position
START (ºPº or ºNº
range)Battery positive voltage
switch
VoltageA12 GroundpositionLOCK, ACC, ONNo voltage
ECU±BVoltageC11 GroundIgnition switchONBattery positive voltage
FuseVoltageC11±GroundIgnition switch
positionLOCK, ACC, STARTNo voltage
Rheostat
Li ht t l
ON (Rheostat knob
t d itiBtt ltLight control
VolumeLight control SWturned any position
except fully clock-
Battery voltage or
5V or moreVolume
VoltageA2±Ground
g
HEAD or TAIL and
rheostat volume
except fully clock-
wise)5V or more
VoltageA2 Groundrheostat volume
knob positionOFF (Rheostat knob)
turned fully clockNo voltageknob ositionturned fully clock-
wise)No voltage
GroundA8±GroundConstantContinuity
ContinuityA10±GroundConstantContinuityContinuityA22±GroundConstantContinuity
A23±GroundConstantContinuity
*1 Jack up the vehicle.*2 Shift lever position is ºPº range.
If circuit is not as specified, refer to BE±100 wiring diagrams
and inspect the circuits connected to other parts.
BE±108
±
BODY ELECTRICAL SYSTEM Combination Meter
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CHECK AND ADJUSTMENT
BR0EC±07
BRAKE PEDAL CHECK AND
ADJUSTMENT
1. CHECK THAT PEDAL HEIGHT IS CORRECT
Pedal height from asphalt sheet:150.4±160.4 mm (5.92±6.31 in.)
If the pedal height is incorrect, adjust it.
2. IF NECESSARY, ADJUST PEDAL HEIGHT
(a) Disconnect the connector from the stop light switch.
(b) Loosen the stop light switch lock nut and remove the stop light switch.
(c) Loosen the push rod lock nut.
(d) Adjust the pedal height by turning the pedal push rod.
(e) Tighten the push rod lock nut.
Torque: 25 N Vm (260 kgf Vcm, 19 ft Vlbf)
(f) Install the stop light switch and turn it until it lightly contacts
the pedal stopper.
(g) Turn the stop light switch back one turn.
(h) Check the clearance (A) between stop light switch and pedal.
Clearance:
0.5±2.4 mm (0.02±0.09 in.)
(i) Tighten the stop light switch lock nut.
(j) Connect the connector to the stop light switch.
(k) Check that the stop lights come on when the brake pedal isdepressed, and go off when the brake pedal is released.
(l) After adjusting the pedal height, check the pedal free±play.
HINT: If clearance (A) between the stop light switch and the
brake pedal stopper has been adjusted correctly, the pedal
freeplay will meet the specifications.
3. CHECK THAT PEDAL FREEPLAY IS CORRECT, AS SHOWN
(a) Stop the engine and depress the brake pedal several times until there is no more vacuum left in the booster.
(b) Push in the pedal by hand until the beginning of the second point of resistance is felt, then measure the distance, as
shown.
Pedal freeplay:
1±6 mm (0.04±0.24 in.)
If incorrect, check the stop light switch clearance. And if the
clearance is OK, then troubleshoot the brake system.
HINT: The freeplay to the first point of resistance is due to the
play between the clevis and pin. It is 1±3 mm (0.04±0.12 in.)
on the pedal.
±
BRAKE SYSTEM CHECK AND ADJUSTMENTBR±7
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4. CHECK THAT PEDAL RESERVE DISTANCE IS CORRECT,
AS SHOWN
Release the parking brake.
With the engine running, depress the pedal and measure the
pedal reserve distance, as shown.
Pedal reserve distance at 490 N (50 kgf, 110.2 lbf):
More than 89 mm (3.50 in.)
If the reserve distance is incorrect, troubleshoot the brake
system.
BRAKE BOOSTER OPERATIONAL TEST
BR03P±0B
1. OPERATING CHECK
(a) Depress the bake pedal several times with the engine off and
check that there is no change in the pedal reserve distance.
(b) Depress the brake pedal and start the engine. If the pedal goes down slightly, operation is normal.
2. AIR TIGHTNESS CHECK
(a) Start the engine and stop it after 1 or 2 minutes. Depress the brake pedal several times slowly. If the pedal goes down the
farthest the 1st time, but gradually rises after the 2nd or 3rd
time, the booster is air tight.
(b) Depress the brake pedal while the engine is running, and stop the engine with the pedal depressed. If there is no
change in the pedal reserve travel after holding the pedal for
30 seconds, the booster is air tight.
BRAKE SYSTEM BLEEDING
BR0ED±04
HINT: If any work is done on the brake system or if air in the
brake lines is suspected, bleed the system of air.
NOTICE: Do not let brake fluid remain on painted sur-
faces. Wash it off immediately.
1. REMOVE RESERVOIR CAP Turn the reservoir cap to the ªopenº side and remove it.
2. FILL RESERVOIR WITH BRAKE FLUID
Fluid: SAE J1703 or FMVSS NO.116DOT3
BR±8±
BRAKE SYSTEM CHECK AND ADJUSTMENT
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SPEED SENSOR SIGNAL CHECK
1. Turn the ignition switch to OFF.
2. Using SST, connect terminals Ts and E1 of DLC1.SST 09843±18020
3. Start the engine.
4. Check that the ABS warning light blinks. HINT: If the ABS warning light does not blink, inspect the ABS
warning light circuit (see page BR±144).
5. Drive vehicle straight forward. HINT: Drive vehicle faster than 45 km/h (28 mph) for several
seconds.
6. Stop the vehicle.
7. Using SST, connect terminals Tc and E1 of DLC1.
SST 09843±18020
8. Read the number of blinks of the ABS warning light. HINT: See the list of diagnosis trouble codes shown on the
next page.
If every sensor is normal, a normal code is output (A cycle of
0.25 sec. on and 0.25 sec. OFF is repeated).
If 2 or more malfunction are indicated at the same time, the
lowest numbered code will be displayed 1st.
9. After performing the check, disconnect terminals Ts and E1,Tc and E1 of DLC1, and ignition switch turned off.
BR±80
±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)
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(b) Check the belt tensioner operation.w Check that the belt tensioner moves downward
when the drive belt is pressed down at the points
indicated in the illustration with approx. 98 N ( 10
kgf, 22.0 lbf) of force.
w Check the alignment of the belt tensioner pulley to
make sure the drive belt has not slipped off the
pulley.
If necessary, replace the belt tensioner.
w Check that the arrow mark on the belt tensioner falls
within area A of the scale.
If it is outside area A, replace the drive belt.
HINT:
w When a new belt is installed, it should lie within area B.
If not, the drive belt is not correct.
w After installing a belt, check that it fits properly in the
ribbed grooves.
w Check by hand to confirm that the belt has not slipped
out of the groove on the bottom of the pulley.
4. REMOVE ENGINE UNDER COVER
5. VISUALLY CHECK ALTERNATOR WIRING AND LISTEN FOR ABNORMAL NOISES
(a) Check that the wiring is in good condition.
(b) C h e c k t h a t t h e r e i s n o a bnormal noise from the
alternator while the engine is running.
6. INSPECT CHARGE WARNING LIGHT CIRCUIT (a) Warm up the engine and then turn it off.
(b) Turn off all accessories.
(c) Turn the ignition switch ON. Check that the charge
warning light is lit.
(d) Start the engine. Check that the light goes off.
If the light does not go off as specified, troubleshoot the
charge light circuit.
CH±6
±
CHARGING SYSTEM On±Vehicle Inspection
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8. INSPECT CHARGING CIRCUIT WITH LOAD(a) With the engine running at 2,000 rpm, turn on the highbeam headlights and place the heater blower switch at
ºHIº.
(b) Check the reading on the ammeter.
Standard amperage: 30 A or more
If the ammeter reading is less than standard amperage, re-
pair the alternator. (See page CH±9)
HINT: With the battery fully charged, the indication will some-
times be less than standard amperage.
9. REINSTALL ENGINE UNDER COVER
CH±8
±
CHARGING SYSTEM On±Vehicle Inspection
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EG0B4±0K
ENGINE OIL INSPECTION
1. CHECK OIL QUALITYCheck the oil for deterioration, entry of water, discoloring or
thinning.
If oil quality is visibly poor, replace the oil.
Oil grade:
API grade SG or SH, Energy±Conserving II or ILSAC
multigrade engine oil. Recommended viscosity is as
shown in the illustration, with SAE 5W±30 being the
preferred engine oil.
Drain and refill capacity: w/ Oil filter change
4.8 liters (5.1 US qts, 4.2 lmp. qts)
w/o Oil filter change
4.5 liters (4.8 US qts, 4.0 lmp. qts)
2. CHECK ENGINE OIL LEVELThe oil level should be between the ªLº and ªFº marks on the
dipstick.
If low, check for leakage and add oil up to the ªFº mark.
EG3E2±01
BATTERY INSPECTION
1. CHECK BATTERY ELECTROYTE LEVEL AND VOLTAGE
(a) Check the electrolyte quantity of each cell.If under the lower level, replace the battery (or add distilled
water if possible.). Need to check the charging system.
(b) Measure the battery voltage between the terminals negative (±) and positive (+) of the battery.
Standard voltage:
12.7±12.9 V at 20 5C (68 5F)
HINT:
w Before measuring the voltage, turn the ignition switch
OFF and turn off the electrical systems (headlight,
blower motor, rear defogger etc.) for 60 seconds to
remove the surface charge.
EG±10
±
1UZ±FE ENGINE ENGINE MECHANICAL
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40. RECONNECT NEGATIVE TERMINAL CABLE TOBATTERY
41. REFILL WITH ENGINE COOLANT
42. START ENGINE AND CHECK FOR LEAKS
EG21T±02
IGNITION TIMING INSPECTION
1. REMOVE UPPER HIGH±TENSION CORD COVER
(a) Remove the 2 bolts.
(b) Disconnect the front side claw groove of the upper cord cover
from the claw of lower cord cover, and remove the upper cord
cover.
2. WARM UP ENGINE Allow the engine to warm up to normal operating tempera-
ture.
3. CONNECT TACHOMETER AND TIMING LIGHT TO ENGINE
Connect the tester probe of a tachometer to terminal IG
of
the DLC1.
HINT: Set the tachometer to the 4±cylinder range.
NOTICE:
w Never allow the tachometer terminal to touch ground as
it could result in damage to the igniter and/or ignition
coil.
w As some tachometers are not compatible with this
ignition system, we recommend that you confirm the
compatibility of your unit before use.
4. INSPECT IGNITION TIMING
(a) Using SST, connect terminals TE1 and E1 of the DLC 1.
SST 09843±18020
EG±32
±
1UZ±FE ENGINE ENGINE MECHANICAL
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