1997 SUBARU LEGACY check engine light

2. Engine Noise
Type of sound Condition Possible cause
Regular clicking soundSound increases as engine
speed increases.Valve mechanism is defective.
Incorrect valve clearance
Worn camshaft
Broken valve spring
Heavy and dull clankOil pressure is low.Worn crankshaft main bearing
Worn connecting rod bearing (big end)
Oil pressure is normal.Loose flywheel mounting bolts
Damaged engine mounting
High-pitched clank
(Spark knock)Sound is noticeable when
accelerating with an overload.Ignition timing advanced
Accumulation of carbon inside combustion chamber
Wrong spark plug
Improper gasoline
Clank when engine speed is
medium (1,000 to 2,000 rpm).Sound is reduced when fuel
injector connector of noisy
cylinder is disconnected.
(NOTE*)Worn crankshaft main bearing
Worn bearing at crankshaft end of connecting rod
Knocking sound when engine
is operating under idling speed
and engine is warm.Sound is reduced when fuel
injector connector of noisy
cylinder is disconnected.
(NOTE*)Worn cylinder liner and piston ring
Broken or stuck piston ring
Worn piston pin and hole at piston end of connecting rod
Sound is not reduced if each
fuel injector connector is
disconnected in turn. (NOTE*)Unusually worn valve lifter
Worn camshaft journal bore in crankcase
Squeaky sound—Insufficient generator lubrication
Rubbing sound—Defective generator brush and rotor contact
Gear scream when starting
engine—Defective ignition starter switch
Worn gear and starter pinion
Sound like polishing glass with
a dry cloth—Loose drive belt
Defective engine coolant pump shaft
Hissing sound—Loss of compression
Air leakage in air intake system, hoses, connections or
manifolds
Timing belt noise—Loose timing belt
Belt contacting case/adjacent part
Valve tappet noise—Incorrect valve clearance
NOTE*:
When disconnecting fuel injector connector, Malfunction Indicator Light (CHECK ENGINE light) illuminates and trouble code is stored in
ECM memory.
Therefore, carry out the CLEAR MEMORY MODE and INSPECTION MODE after connecting fuel injector connector. (Ref. to 2-7 On-Board
Diagnostics II System.)
80
2-3bDIAGNOSTICS
2. Engine Noise

1. Engine Lubrication System
Before troubleshooting, make sure that the engine oil level
is correct and no oil leakage exists.
Trouble Possible cause Corrective action
1. Warning light remains
on.1) Oil pressure switch
failureCracked diaphragm or oil leakage within switch Replace.
Broken spring or seized contacts Replace.
2) Low oil pressureClogged oil filter Replace.
Malfunction of oil by-pass valve of oil filter Clean or replace.
Malfunction of oil relief valve of oil pump Clean or replace.
Clogged oil passage Clean.
Excessive tip clearance and side clearance of oil
pump rotor and gearReplace.
Clogged oil strainer or broken pipe Clean or replace.
3) No oil pressureInsufficient engine oil Replenish.
Broken pipe of oil strainer Replace.
Stuck oil pump rotor Replace.
2. Warning light does not
go on.1) Burn-out bulb Replace.
2) Poor contact of switch contact points Replace.
3) Disconnection of wiring Repair.
3. Warning light flickers
momentarily.1) Poor contact at terminals Repair.
2) Defective wiring harness Repair.
3) Low oil pressureCheck for the same pos-
sible causes as listed in
1.—2)
17
2-4DIAGNOSTICS
1. Engine Lubrication System

10) After completion of fitting, make sure that the selector
lever operates smoothly all across the operating range.
11) Connect the harnesses and check the following items.
(1) The engine starts operating when selector lever is
in position“P”, but not in other positions.
(2) The back-up light is lit when the selector lever is in
position“R”, but not in other positions.
B3M0348A
12) Check selector lever operation.
WARNING:
Stop the engine while checking operation of selector
lever.
(1) Check that selector lever does not move from“N”
to“R”without pushing the button.
(2) Check that selector lever does not move from“R”
to“P”without pushing the button.
(3) Check that selector lever does not move from“P”
to“R”without pushing the button and the brake pedal
depressed. [With ignition key set at“ON”.]
(4) Check that selector lever does not move from“3”to
“2”without pushing the button.
13) Check shift-lock system.
(1) Ensure ignition switch rotates from“ACC”to
“LOCK”when the selector lever is set at“P”. Also check
that ignition key can be removed from the“LOCK”posi-
tion only.
(2) Ensure selector lever moves from“P”to any other
position when the brake pedal is depressed with igni-
tion key set at“ON”or“START”.
16
3-3SERVICE PROCEDURE
2. Automatic Transmission

6) Check
(1) When reassembly procedures have been
completed, turn shaft by hand to ensure it turns
smoothly. If it binds or other unusual conditions are
evident, disassemble again and check for foreign mat-
ter trapped on sliding surfaces and improper installa-
tion. Eliminate the cause of trouble.
(2) Check followings by referring to“CHECK”article.

Excessive play in pulley shaft

Ditch deflection of pulley

Resistance to rotation of pulley

Measurement of generated oil pressure
F: INSTALLATION
1) Install bracket on engine.
Tightening torque:
22±2 N⋅m (2.2±0.2 kg-m, 15.9±1.4 ft-lb)
2) Install oil pump on oil tank as follows outside the
vehicle:
NOTE:
Prior to installation, make sure that all oil is removed from
oil pump, oil tank and pipe.
B4M0562A
3) Place oil pump in vise.
CAUTION:
Do not place oil pump directly in vise; use soft pads
and hold oil pump lightly to protect it.
4) Install O-ring on oil pump.
CAUTION:
Discard old O-ring and replace with a new one.
5) Install oil tank on oil pump.
Tightening torque:
Bolt C: 15.7±2.4 N⋅m
(1.60±0.24 kg-m, 11.58±1.77 ft-lb)
Bolt D: 18.1±2.5 N⋅m
(1.85±0.25 kg-m, 13.35±1.84 ft-lb)
CAUTION:
Discard old seal washer and replace with a new one.
78
4-3SERVICE PROCEDURE
8. Oil Pump (Power Steering System)

G4M0744
2. AIR TIGHTNESS CHECK
Start engine, and run it for 1 to 2 minutes, then turn it off.
Depress brake pedal several times applying the same
pedal force as that used in ordinary braking operations.
The pedal stroke should be greatest on the 1st depression,
and it should become smaller with each successive
depression. If no change occurs in the pedal height while
in a depressed state, brake booster is faulty.
NOTE:

In the event of defective operation, inspect the condition
of the check valve and vacuum hose.

Replace them if faulty and conduct the test again.

If no improvement is observed, check precisely with
gauges.
G4M0914
3. OPERATION CHECK
1) With engine off, depress brake pedal several times
applying the same pedal force and make sure that the
pedal height does not vary with each depression of the
pedal.
2) With brake pedal depressed, start engine.
3) As engine starts, brake pedal should move slightly
toward the floor. If no change occurs in the pedal height,
brake booster is faulty.
NOTE:
If faulty, check precisely with gauges.
4. LOADED AIR TIGHTNESS CHECK
Depress brake pedal while engine is running, and turn off
engine while the pedal is still depressed. Keep the pedal
depressed for 30 seconds; if no change occurs in the pedal
height, brake booster is functioning normally; if the pedal
height increases, it is faulty.
NOTE:
If faulty, check precisely with gauges.
57
4-4SERVICE PROCEDURE
6. Brake Booster

D: ABS SEQUENCE CONTROL
1) Under the ABS sequence control, after the hydraulic
unit solenoid valve is driven, the operation of the hydraulic
unit can be checked by means of the brake tester or pres-
sure gauge.
2) ABS sequence control can be started by diagnosis con-
nector or select monitor.
B4M0082D
1. OPERATIONAL GUIDELINES OF THE ABS
SEQUENCE CONTROL WITH DIAGNOSIS
CONNECTOR
1) Connect diagnosis terminals to terminals No. 3 and No.
6 of the diagnosis connector beside driver’s seat heater
unit.
2) Set the speed of all wheels at 4 km/h (2 MPH) or less.
3) Turn ignition switch OFF.
4) Within 0.5 seconds after the ABS warning light goes
out, depress the brake pedal and hold it immediately after
ignition switch is turned to ON.
CAUTION:
Do not depress the clutch pedal.
NOTE:

When the ignition switch is set to on, the brake pedal
must not be depressed.

Engine must not operate.
5) After completion of ABS sequence control, turn ignition
switch OFF.
2. OPERATIONAL GUIDELINES OF THE ABS
SEQUENCE CONTROL WITH SELECT MONITOR
1) Connect select monitor to data link connector beside
driver’s seat heater unit.
2) Turn ignition switch ON.
3) Put select monitor to ABS mode.
B4M0635
4) PressFD1ENTkey.
83
4-4SERVICE PROCEDURE
15. Hydraulic Unit for ABS System (ABS 5.3 Type)

G4M0436
16) Check the pedal stroke.
While the engine is idling, depress the brake pedal with a
490 N (50 kg, 110 lb) load and measure the distance
between the brake pedal and steering wheel. With the
brake pedal released, measure the distance between the
pedal and steering wheel again. The difference between
the two measurements must be less than specified.
Specified pedal stroke:
With TCS
95 mm (3.74 in)
When depressing brake pedal with a 490 N (50 kg,
110 lb) load.
If the distance is more than specifications, there is a
possibility that air is in the brake line. Bleed air from the
brake line.
17) Turn ignition switch OFF.
18) Disconnect select monitor or diagnosis terminal.
19) Add brake fluid to the required level (MAX. level) of
reserve tank.
20) As a final step, test run the vehicle at low speed and
apply brakes relatively hard 2 to 3 times to ensure that
brakes provide normal braking action on all four wheels
without dragging and uneven braking.
2. CONDITIONS FOR AIR BLEEDING CONTROL
Stop light
switchTCS OFF
switchPump
motorTCS
valveFRO
RLOFLO
RROTCS
operating
indicator
lightABS
warning
lightTCS
warning
light
Air
bleeding
control is
operating.OFF ON ON Close Close Close ON ON ON
ON ON OFF Open Open Close ON ON OFF
ON ON OFF Open Close Open ON OFF ON
ON or OFF OFF OFF Open Close Close ON OFF OFF
Stops tem-
porarily.*——OFF Open Close Close OFF OFF OFF
Prohibited.——OFF Open Close Close OFF ON ON
*: When brake fluid level switch detects brake fluid in LOW level, control operation stops temporarily. After refilling brake fluid, operation
re-starts.
101
4-4SERVICE PROCEDURE
19. Air Bleeding (With TCS model)

D: ABS SEQUENCE CONTROL
1) Under the ABS sequence control, after the hydraulic
unit solenoid valve is driven, the operation of the hydraulic
unit can be checked by means of the brake tester or pres-
sure gauge.
2) ABS sequence control can be started by diagnosis con-
nector or select monitor.
B4M0082C
1. OPERATIONAL GUIDELINES OF THE ABS
SEQUENCE CONTROL WITH DIAGNOSIS
CONNECTOR
1) Connect diagnosis terminals to terminal No. 4 of the
diagnosis connector beside driver’s seat heater unit.
2) Ignition switch is turned to ON.
3) Make sure only the start code (code 11) is shown in
normal condition.
NOTE:
When trouble codes are stored in memory, repair the faulty
parts.
4) Set the speed of all wheels at 10 km/h (6 MPH) or less.
5) Turn ignition switch OFF.
6) Within 0.5 seconds after the ABS and TCS warning
lights go out, depress the brake pedal and hold it immedi-
ately after engine starts.
NOTE:

When the ignition switch is set to on, the brake pedal
must not be depressed.

Engine must operate.

If brake pedal is not depressed within 0.5 seconds after
ABS and TCS warning lights go out, the trouble code mode
comes on.
7) After completion of ABS sequence control, turn ignition
switch OFF.
2. OPERATIONAL GUIDELINES OF THE ABS
SEQUENCE CONTROL WITH SELECT MONITOR
1) Connect select monitor to data link connector beside
driver’s seat heater unit.
2) Engine starts.
3) Put select monitor to TCS mode.
4) put select monitor to FBI mode. Make sure code 11 is
indicated.
NOTE:
When trouble codes are stored in memory, repair the faulty
parts.
109
4-4SERVICE PROCEDURE
20. Hydraulic Unit for ABS/TCS System