Trouble	Possible cause		Corrective action
	1. Warning light remains on.	1) Oil pressure switch failure	Cracked diaphragm or oil leakage within switch	Replace.
			Broken spring or seized contacts	Replace.
		2) Low oil pressure	Clogged 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 gear	Replace.
			Clogged oil strainer or broken pipe	Clean or replace.
		3) No oil pressure	Insufficient 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 pressure		Check for the same possible causes as listed in 1.-2).