I had this problem during the journey from my house to workplace this morning. the indicator light suddenly on and stable there. if car went through some uneven or got bumps, the light also followed the step like on then off. after reached my office, i turned engine off for 5min and checked the oil level. no problem on this. then while engine was running, i opened the oil cap to test the oil pump pressure. no problem also because can feel strong wind blowing from the hole. during lunch time, i drove the car out again. result same, indicator on and off. car was then parked under hot sun for about 1hr. when drove back, light did not turn on at all. does that means sensor problem? where is the sensor located and how to do diagnose on this?