The oil warning light refers to oil pressure, not level. If there really is low oil pressure it is more likely to occur at low speeds and when idling, but a defective sending unit can cause that too. If you already have a new one coming, try that first. Normally we would check the actual pressure with a mechanical gauge to see what it really is.
Once the Check Engine light turned on there should be a diagnostic fault code in the Engine Computer. That will indicate the circuit or system that needs further diagnosis.
Thursday, June 6th, 2013 AT 3:00 PM