[jordanc]

My n54 has had the check engine light come on and off over the span of days and it isn’t remembering time. Does anyone know why, other than that the car runs perfect and has no issues.

[Ohio Enthusiast]

Typically that's due to the gas cap. Inspect the gasket on it, and potentially just replace outright. If you have iDrive it should give a notification about tightening the gas cap before illuminating the Service Engine Soon light.
A generic code reader should show an emission code, typically P0442. A BMW specific reader might give some more details.

[Podunk]

Originally Posted by Ohio Enthusiast

Typically that's due to the gas cap. Inspect the gasket on it, and potentially just replace outright. If you have iDrive it should give a notification about tightening the gas cap before illuminating the Service Engine Soon light.
A generic code reader should show an emission code, typically P0442. A BMW specific reader might give some more details.

kidna odd that a gas cap would affect the clock though don't you think?

mine also pops on randomly, but mine is random Vanos codes, and they are very rare. ( usually only happens around time for an oil change) but my clock keeps time.

this sounds like a power issue, or bad battery.

OP, if you can scan it when the CES/CEL is on, it would give you the best idea of what to look for.

there are cables for 24 USD on amazon, and bimmergeeks protools works well, and has a master license for 150. so for under 200 USD you can have a pretty decent scan tool out of your phone for your BMW, that can also do feature coding.

[suspect]

Originally Posted by Podunk

kidna odd that a gas cap would affect the clock though don't you think?

mine also pops on randomly, but mine is random Vanos codes, and they are very rare. ( usually only happens around time for an oil change) but my clock keeps time.

this sounds like a power issue, or bad battery.

OP, if you can scan it when the CES/CEL is on, it would give you the best idea of what to look for.

there are cables for 24 USD on amazon, and bimmergeeks protools works well, and has a master license for 150. so for under 200 USD you can have a pretty decent scan tool out of your phone for your BMW, that can also do feature coding.

I would second getting the cable off Amazon and download INPA.MHD monitor license is even better for this car.