Oil pressure light comes on when braking
 

Brought a 2004 Mitsubushi Outlander LS AWD 10 days ago from a Nissan car dealer. Oil pressure light comes on (initially flickers) when braking, and goes off while accelerating or in motion. It seems I have no problem for 10 minutes of drive after cold start. The SUV has 102,000 Kms on it. The following are the facts

• The dealer changed the oil and oil filter when I brought. The oil level is normal and clear.
• At first, the dealer suspected a faulty pressure switch (without diagnosis) and replaced it right away.
• No visible oil leaks or any visible damage to the switch cable (dealer inspected)

So what else could be the problem? Some reviews says faulty oil pump, defective oil filter, wrong oil, drop in pressure, etc. Anyways I will be getting it diagonised on coming Monday and keep my fingers crossed. I will post the outcome. Meanwhile your comments are most welcome.

"At first, the dealer suspected a faulty pressure switch (without diagnosis) and replaced it right away."

It is was oil pressure sensor, got it replaced and no more oil pressure light surprise

Thanks for posting the results. Way too many people get advice and don't post back. Unfortunately no one gave you advice but you posted back anyway. Glad it got fixed.

Not any big thing but if you could clear something up for me and it may just be the terminology. Initially the dealer checked the switch and then relaced the sensor, and that fixed your oil light problem. Maybe they call it different things on the different model years. On my car, the one that controls the "idiot" oil light is the oil pressure switch which is a simple switch (N.O. & N.C.). The one that sends varying voltage to the oil pressure gauge is the oil pressure sending unit.

So what did they replace that fixed the light?

Remember I had mentioned that Nissan service center did change the pressure switch without diagnosis because he thought most of 'Oil pressure light on' problem is related to the switch. As it did not solve the problem, the dealer and myself kept on thinking that are we facing problems with oil pressure. They then escalated the problem to Mitsubishi service center where upon diagnosis they reported switch is all right, oil pressure is all right but oil pressure sensor is bad. I was so relieved.

It was hard to believe that this vehicle was equipped with sensor and switch separately. Any idea?

Not hard to believe. I believe all cars with oil pressure gauges also have an "no oil pressure" light. The oil pressure gauge is actually a DC volt meter. A change in oil pressure makes a proportional voltage output change from the sensor. The "no oil pressure" light tells you when the oil pressure is lost.