I have a 2007 Chevrolet Impala V6 Flex-Fuel. Recently, the Check Engine Light came on. I decided to drive the car with the light on for a few days as my engine code reader was packed away. About four days after the light came on, I topped off the engine with a quart of oil (this car loses about a quart a month). The CEL went off the next morning and I never had the opportunity to read any code off.

Is there any plausible reason that the CEL would have been triggered by a low oil condition or would have been resolved by adding more oil? Is this likely nothing more than a coincidence? The low oil warning on the car did not activate at any time during this occurrence.

Note that I don't need help with the light - it is off. I'm asking how likely it was that topping off the oil was what fixed it. To my recollection, this had not happened before.

  • Only way to know for sure is to read the codes stored in the PCM using an OBD2 reader.
    – Moab
    Commented Jun 27, 2018 at 14:58
  • 1
    Sounds like a coincidence unless it throws codes for low oil pressure and has a separate low oil light, which seems unlikely. As Moab said, only way to know is to check the codes. Commented Jun 27, 2018 at 19:12

1 Answer 1


I don't know for sure about the '07 Impala, but most cars I'm aware of have an oil pressure sensor. When the pressure gets below a certain level, it will throw an "idiot" light, which can be the CEL. Other cars have a specific light for the oil pressure (which is usually an oil can symbol with oil dripping out of it). Some vehicles also have an oil level sensor. When the oil reserve gets below a certain point, it will put on an idiot light as well ... you guessed it. In some cases that's the CEL. It could very well be the CEL came on to let you know your oil level was low, which was cured by topping it off. In the situations listed above, neither will have a stored code behind the CEL. It just means exactly what the name implies ... check your engine. Like I said, I'm not positive if this is your case, but it very well could be what's going on.

  • Usually I upvote your answers, but now I'm feeling hard to believe the oil pressure sensor will trigger the CEL. I mean, if you really have low oil pressure, you want to STOP! Stop driving the car and have it towed. The CEL is for non-damaging conditions like faulty lambda sensor. As a yellow light, it means have it fixed whenever convenient, not have it fixed now. The oil level sensor could perfectly well trigger the CEL, if the car is equipped with an oil level sensor and at the same time the car manufacturer wanted to save the cost of an additional warning light.
    – juhist
    Commented Jun 27, 2018 at 15:41
  • 1
    @juhist - Please note I said "some cars". I don't know whether the Impala is one of them. All I'm pointing out is, the OP's scenario is feasible. The CEL can be used for this, but it doesn't mean it will be used for it. It's probably older cars which would trip the engine light for oil pressure (not have a specific indicator), and not the OP's. When oil pressure trips the engine light, it usually flickers as the pressure drops above/below the threshold. In any case, there won't be code stored behind the light coming on. Commented Jun 27, 2018 at 16:14
  • 1
    An 07 Impala won’t set a code unless it’s a circuit code, mil won’t illuminate. It will set timing performance codes though.
    – Ben
    Commented Jun 27, 2018 at 16:26

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .