Yellow engine warning light

[Ewazix]

If you don't get a taker locally I recommend a bluetooth obd2 dongle from ebay for £5 upwards and TorquePro App on a mobile, mine works fine for basic code reading/re-setting and gets the diagnosis process started. It's been used on various mates cars, not just BMW, so is always handy.

 

[srhutch]

Could be the battery. Electrical gremlins are a first sign.

Had it on mine last year, and it's kept on a battery maintainer.

Mine was lit up like a xmas tree to as to. So if your battery is old might be worth changing.

 

[Ewazix]

Also suspect loose, dirty or damaged wiring/connectors interfering with voltages

 

[Roundozo]

You might also want to check if you have any split hoses or lose joints.