Engine Mangement light comes on when coolant is low but stays on
 

The engine Management light keeps lighting up on My 2000 STS. I think it may be somehting to do with the coolant level as I have only had the car 6 weeks and have had to top it up twice. Does anyone know other reasons why it may come on where there is no major problem. I know that leaving the fuel cap open can do this but should it not go out once closed? I don't want to keep paying a diagnostic expert £25 just to switch it off every time.

You need to get a code reader / clearer, they are normally inexpensive $80.00 US. A scanner costs more, but does more. Either can be helpful as far know if a trip to local garage is required, which can save you money in regards to loose fuel caps. You can post code(s) for advice prior to going to garage, just don't clear code if that's where you intend to go. When code is cleared failure data is lost, which can help in diagnosis of concern. When MIL(malfunction indicator light) OBD II; light will stay on until faulty system passes self diagnostic test 2 times, which is different than OBD I. Code will be stored for 40 key cycles afterward. A basic cooling system pressure test may indicate where coolant is leaking / going.

ditto slowroll ..
i be more concerned why the coolant gets low. that is kind of really important.

https://www.cadillacforum.com/forum/...hlight=coolant



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