General Diagnostic Table - Subaru Legacy 2004 Service Manual

8. General Diagnostic Table

A: INSPECTION
Before performing diagnosis, make sure that the engine oil level is correct and no oil leakage exists.
Symptom
1. Warning light remains
on.
2. Warning light does
not come on.
3. Warning light flickers
momentarily.
General Diagnostic Table
Cracked diaphragm or oil leakage within switch
1) Oil pressure switch
failure
Broken spring or seized contacts
Clogging of oil filter
Malfunction of oil by-pass valve in oil filter
Malfunction of oil relief valve in oil pump
2) Low oil pressure
Clogged oil passage
Excessive tip clearance and side clearance of oil
pump rotor and gear
Clogged oil strainer or broken pipe
Insufficient engine oil
3) No oil pressure Broken pipe of oil strainer
Stuck oil pump rotor
1) Malfunction of combination meter
2) Poor contact of switch contact points
3) Disconnection of wiring
1) Poor contact at terminals
2) Defective wiring harness
3) Low oil pressure
LU(H4SO 2.0)-19
Possible cause
LUBRICATION
Corrective action
Replace.
Replace.
Replace.
Clean or replace.
Clean or replace.
Clean.
Replace.
Clean or replace.
Replenish.
Replace.
Replace.
Replace.
Replace.
Repair.
Repair.
Repair.
Check for the same
possible causes as
listed in 1) — 2).