1999 SUBARU LEGACY relay

1. Engine Trouble in General
NOTE:
ªRANKº shown in the chart refer to the possibility of reason for the trouble in order (ªVery oftenº to ªRarelyº)
A Ð Very often
B Ð Sometimes
C Ð Rarely
TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK
1. Engine will not start.
1) Starter does not turn.IStarterIDefective battery-to-starter harness B
IDefective starter switch C
IDefective inhibitor switch or neutral switch C
IDefective starter B
IBatteryIPoor terminal connecton A
IRun-down battrey A
IDefective charging system B
IFrictionISeizure of crankshaft and connecting rod bearing C
ISeized camshaft C
ISeized or stuck piston and cylinder C
2) Initial combustion does
not occur.IStarterIDefective starter C
IFuel injection system A
IFuel lineIDefective fuel pump and relay A
ILack of or insufficient fuel B
IBeltIDefective B
IDefective timing B
ICompressionIIncorrect valve clearance C
ILoosened spark plugs or defective gasket C
ILoosened cylinder head bolts or defective gasket C
IImproper valve seating C
IDefective valve stem C
IWorn or broken valve spring B
IWorn or stuck piston rings, cylinder and piston C
IIncorrect valve timing B
IImproper engine oil (low viscosity) B
3) Initial combustion occur.IFuel injection system A
IIntake systemIDefective intake manifold gasket B
IDefective throttle body gasket B
IFuel lineIDefective fuel pump and relay C
IClogged fuel line C
ILack of or insufficient fuel B
IBeltIDefective B
IDefective timing B
ICompressionIIncorrect valve clearance C
ILoosened spark plugs or defective gasket C
ILoosened cylinder head bolts or defective gasket C
IImproper valve seating C
IDefective valve stem C
IWorn or broken valve spring B
IWorn or stuck piston rings, cylinder and piston C
IIncorrect valve timing B
IImproper engine oil (low viscosity) B
73
[K100]2-3aDIAGNOSTICS
1. Engine Trouble in General

TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK
4) Engine stalls after initial
combustion.Fuel injection system A
IIntake systemILoosened or cracked intake uct B
ILoosened or cracked PCV hose C
ILoosened or cracked vacuum hose C
IDefective intake manifold gasket B
IDefective throttle body gasket B
IDirty air cleaner element C
IFuel lineIClogged fuel line C
ILack of or insufficient fuel B
IBeltIDefective B
IDefective timing B
ICompressionIIncorrect valve clearance C
ILoosened spark plugs or defective gasket C
ILoosened cylinder head bolts or defective gasket C
IImproper valve seating C
IDefective valve stem C
IWorn or broken valve spring B
IWorn or stuck piston rings, cylinder and piston C
IIncorrect valve timing B
IImproper engine oil (low viscosity) B
2. Rough idle and engine stall Fuel injection system A
IIntake systemILoosened or cracked intake duct A
ILoosened or cracked PCV hose A
ILoosened or cracked vacuum hose A
IDefective intake manifold gasket B
IDefective throttle body gasket B
IDefective PCV valve C
ILoosened oil filter cap B
IDirty air cleaner element C
IFuel lineIDefective fuel pump and relay C
IClogged fuel line C
ILack of or insufficient fuel B
IBeltIDefective timing C
ICompressionIIncorrect valve clearance B
ILoosened spark plugs or defective gasket B
ILoosened cylinder head bolts or defective gasket B
IImproper valve seating B
IDefective valve stem C
IWorn or broken valve spring B
IWorn or stuck piston rings, cylinder and piston B
IIncorrect valve timing A
IImproper engine oil (low viscosity) B
ILubrication systemIIncorrect oil pressure B
IDefective rocker cover gasket C
ICooling systemIOverheating C
IOthersIMalfunction of evaporative emission control system A
IStuck or damaged throttle valve B
IAccelerator cable out of adjustment C
74
2-3a[K100]DIAGNOSTICS
1. Engine Trouble in General

TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK
3. Low output, hesitation and
poor accelerationIFuel injection system A
IIntake systemILoosened or cracked intake duct A
ILoosened or cracked PCV hose A
ILoosened or cracked vacuum hose B
IDefective intake manifold gasket B
IDefective throttle body gasket B
IDefective PCV valve B
ILoosened oil filter cap B
IDirty air cleaner element A
IFuel lineIDefective fuel pump and relay B
IClogged fuel line B
ILack of or insufficient fuel C
IBeltIDefective timing B
ICompressionIIncorrect valve clearance B
ILoosened spark plugs or defective gasket B
ILoosened cylinder head bolts or defective gasket B
IImproper valve seating B
IDefective valve stem C
IWorn or broken valve spring B
IWorn or stuck piston rings, cylinder and piston C
IIncorrect valve timing A
IImproper engine oil (low viscosity) B
ILubrication systemIIncorrect oil pressure B
ICooling systemIOverheating C
IOver cooling C
IOthersIMalfunction of evaporative emission control system A
4. SurgingIFuel injection system A
IIntake systemILoosened or cracked intake duct A
ILoosened or cracked PCV hose A
ILoosened or cracked vacuum hose A
IDefective intake manifold gasket B
IDefective throttle body gasket B
IDefective PCV valve B
ILoosened oil filter cap B
IDirty air cleaner element B
IFuel lineIDefective fuel pump and relay B
IClogged fuel line B
ILack of or insufficient fuel C
IBeltIDefective timing B
ICompressionIIncorrect valve clearance B
ILoosened spark plugs or defective gasket C
ILoosened cylinder head bolts or defective gasket C
IImproper valve seating C
IDefective valve stem C
IWorn or broken valve spring C
IWorn or stuck piston rings, cylinder and piston C
IIncorrect valve timing A
IImproper engine oil (low viscosity) B
ICooling systemIOverheating B
IOthersIMalfunction of evaporative emission control system C
75
[K100]2-3aDIAGNOSTICS
1. Engine Trouble in General

1. Engine Trouble in General
NOTE:
A, B and C shown in the RANK of table refer to the
possibility of reason for the trouble in order (ªVery
oftenº to ªRarelyº).A : Very often
B : Sometimes
C : Rarely
TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK
1. Engine will not start.
1) Starter does not turn.IStarterIDefective battery-to-starter harness B
IDefective starter switch C
IDefective inhibitor switch or neutral switch C
IDefective starter B
IBatteryIPoor terminal connection A
IRun-down battery A
IDefective charging system B
IFrictionISeizure of crankshaft and connecting rod bearing C
ISeized camshaft C
ISeized or stuck piston and cylinder C
2) Initial combustion does
not occur.IStarterIDefective starter C
IFuel injection system A
IFuel lineIDefective fuel pump and relay A
ILack of or insufficient fuel B
IBeltIDefective B
IDefective timing B
ICompressionIIncorrect valve clearance C
ILoosened spark plugs or defective gasket C
ILoosened cylinder head bolts or defective gasket C
IImproper valve seating C
IDefective valve stem C
IWorn or broken valve spring B
IWorn or stuck piston rings, cylinder and piston C
IIncorrect valve timing B
IImproper engine oil (low viscosity) B
3) Initial combustion
occurs.IFuel injection system A
IIntake systemIDefective intake manifold gasket B
IDefective throttle body gasket B
IFuel lineIDefective fuel pump and relay C
IClogged fuel line C
ILack of/or insufficient fuel B
IBeltIDefective B
IDefective timing B
ICompressionIIncorrect valve clearance C
ILoosened spark plugs or defective gasket C
ILoosened cylinder head bolts or defective gasket C
IImproper valve seating C
IDefective valve stem C
IWorn or broken valve spring B
IWorn or stuck piston rings, cylinder and piston C
IIncorrect valve timing B
IImproper engine oil (low viscosity) B
71
[K100]2-3bDIAGNOSTICS
1. Engine Trouble in General

TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK
4) Engine stalls after initial
combustion.IFuel injection system A
IIntake systemILoosened or cracked intake duct B
ILoosened or cracked PCV hose C
ILoosened or cracked vacuum hose C
IDefective intake manifold gasket B
IDefective throttle body gasket B
IDirty air cleaner element C
IFuel lineIClogged fuel line C
ILack of or insufficient fuel B
IBeltIDefective B
IDefective timing B
ICompressionIIncorrect valve clearance C
ILoosened spark plugs or defective gasket C
ILoosened cylinder head bolts or defective gasket C
IImproper valve seating C
IDefective valve stem C
IWorn or broken valve spring B
IWorn or stuck piston rings, cylinder and piston C
IIncorrect valve timing B
IImproper engine oil (low viscosity) B
2. Rough idle and engine
stallIFuel injection system A
IIntake systemILoosened or cracked intake duct A
ILoosened or cracked PCV hose A
ILoosened or cracked vacuum hose A
IDefective intake manifold gasket B
IDefective throttle body gasket B
IDefective PCV valve C
ILoosened oil filler cap B
IDirty air cleaner element C
IFuel lineIDefective fuel pump and relay C
IClogged fuel line C
ILack of/or insufficient fuel B
IBeltIDefective timing C
ICompressionIIncorrect valve clearance B
ILoosened spark plugs or defective gasket B
ILoosened cylinder head bolts or defective gasket B
IImproper valve seating B
IDefective valve stem C
IWorn or broken valve spring B
IWorn or stuck piston rings, cylinder and piston B
IIncorrect valve timing A
IImproper engine oil (low viscosity) B
ILubrication systemIIncorrect oil pressure B
IDefective rocker cover gasket C
ICooling systemIOverheating C
IOthersIMalfunction of evaporative emission control system A
IStuck or damaged throttle valve B
IAccelerator cable out of adjustment C
72
2-3b[K100]DIAGNOSTICS
1. Engine Trouble in General

TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK
3. Low output, hesitation
and poor accelerationIFuel injection system A
IIntake systemILoosened or cracked intake duct A
ILoosened or cracked PCV hose A
ILoosened or cracked vacuum hose B
IDefective intake manifold gasket B
IDefective throttle body gasket B
IDefective PCV valve B
ILoosened oil filler cap B
IDirty air cleaner element A
IFuel lineIDefective fuel pump and relay B
IClogged fuel line B
ILack of/or insufficient fuel C
IBeltIDefective timing B
ICompressionIIncorrect valve clearance B
ILoosened spark plugs or defective gasket B
ILoosened cylinder head bolts or defective gasket B
IImproper valve seating B
IDefective valve stem C
IWorn or broken valve spring B
IWorn or stuck piston rings, cylinder and piston C
IIncorrect valve timing A
IImproper engine oil (low viscosity) B
ILubrication systemIIncorrect oil pressure B
ICooling systemIOverheating C
IOver cooling C
IOthersIMalfunction of evaporative emission control system A
4. SurgingIFuel injection system A
IIntake systemILoosened or cracked intake duct A
ILoosened or cracked PCV hose A
ILoosened or cracked vacuum hose A
IDefective intake manifold gasket B
IDefective throttle body gasket B
IDefective PCV valve B
ILoosened oil filler cap B
IDirty air cleaner element B
IFuel lineIDefective fuel pump and relay B
IClogged fuel line B
ILack of/or insufficient fuel C
IBeltIDefective timing B
ICompressionIIncorrect valve clearance B
ILoosened spark plugs or defective gasket C
ILoosened cylinder head bolts or defective gasket C
IImproper valve seating C
IDefective valve stem C
IWorn or broken valve spring C
IWorn or stuck piston rings, cylinder and piston C
IIncorrect valve timing A
IImproper engine oil (low viscosity) B
ICooling systemIOverheating B
IOthersIMalfunction of evaporative emission control system C
73
[K100]2-3bDIAGNOSTICS
1. Engine Trouble in General

1. Engine Cooling System Trouble in General
TroubleCorrective action
Over-heatinga. Insufficient engine coolantReplenish engine coolant, inspect for leakage, and
repair.
b. Loose timing belt Repair or replace timing belt tensioner.
c. Oil on drive belt Replace.
d. Malfunction of thermostat Replace.
e. Malfunction of water pump Replace.
f. Clogged engine coolant passage Clean.
g. Improper ignition timingInspect and repair ignition control system.
On-Board Diagnostics II System
h. Clogged or leaking radiator Clean or repair, or replace.
i. Improper engine oil in engine coolant Replace engine coolant.
j. Air/fuel mixture ratio too leanInspect and repair fuel injection system.
On-Board Diagnostics II System
k. Excessive back pressure in exhaust system Clean or replace.
l. Insufficient clearance between piston and cylinder Adjust or replace.
m. Slipping clutch Repair or replace.
n. Dragging brake Adjust.
o. Improper transmission oil Replace.
p. Defective thermostat Replace.
q. Malfunction of electric fanInspect radiator fan relay, engine coolant temperature
sensor or radiator motor and replace there.
Over-coolinga. Atmospheric temperature extremely low Partly cover radiator front area.
b. Defective thermostat Replace.
Engine coolant
leaks.a. Loosened or damaged connecting units on
hosesRepair or replace.
b. Leakage from water pump Replace.
c. Leakage from water pipe Repair or replace.
d. Leakage around cylinder head gasket Retighten cylinder head bolts or replace gasket.
e. Damaged or cracked cylinder head and crank-
caseRepair or replace.
f. Damaged or cracked thermostat case Repair or replace.
g. Leakage from radiator Repair or replace.
Noisea. Defective drive belt Replace.
b. Defective radiator fan Replace.
c. Defective water pump bearing Replace water pump.
d. Defective water pump mechanical seal Replace water pump.
26
2-5[K100]DIAGNOSTICS
1. Engine Cooling System Trouble in General

9) Take out ECM.
B2M0679A
10) Installation is in the reverse order of removal.
16. Main Relay
A: REMOVAL AND INSTALLATION
1) Disconnect battery ground cable.
G6M0095
2) Remove lower cover and then disconnect con-
nectors.
B5M0024A
3) Lower transmission control module.
4) Remove the front pillar lower trim.

5) Remove fuse box mounting nuts.
6) Lower fuse box.
7) Remove fuse box mounting bracket.
8) Remove screw which retains bracket of main
relay and fuel pump relay.
B2M1191
87
[W16A0]2-7SERVICE PROCEDURE
16. Main Relay