Engine warning light on - 2009 BMW 5 Series

Looks like you have a few issues there.

1. The battery warning. This is indicative of a weak battery and if your battery is 3 years old or more I would replace it.

2. If you have a weak battery this can trigger other warning lights in the vehicle, typically the ABS warning but sometimes other warning lights as well depending on the electronic features in the car. If you replace the battery this should correct the battery warning and most likely the ABS warning if both of these warnings appeared at the same time.
Normally, once the ABS warning is displayed the anti lock braking system(ABS) will be shut down. Whilst your braking will be normal, if you brake too hard and lock up your wheels on a slippery road there is no ABS assist to prevent the brake lock up which you have when the system is working.

3. If the alternator on the engine is not generating sufficient power and thus not charging the battery at all, or very little, you will likely get a battery warning light. I don't know if your 1999 vehicle has a warning light to indicate a faulty alternator or not.

4. Check Engine Light.
You suggested the CE warning has been showing up for a few days and before the battery and ABS warnings popped up.
The CE warning can be caused by dozens of different engine issues.
The vehicle needs to be scanned with the appropriate scan tool to see what fault codes the onboard computer is generating because if you have a CE warning light there will be fault codes generated 99% of the time.

Once these fault codes have been pulled the mechanic can start to diagnose the cause of the problem or problems. Each engine fault code your car's computer is generating can be caused by different types of problems so it is important that they diagnose the issues correctly. Otherwise your Check Engine light will remain on as long as the causes are not identified and fixed.

That depends on the type of oil warning light being displayed. There are 2 types of warning lights

1. Low oil pressure light which all cars have
2. low oil level light which some cars have.

Low OIL PRESSURE warning means the oil pressure is below minimum and when this happens there will be insufficient lubrication of many engine parts because sufficient oil cannot get to all parts of the engine it is required to lubricate. Until the cause is identified and rectified the warning light will remain. If you run your engine with low oil pressure you will cause expensive damage to internal engine components.

Low OIL LEVEL warning means the oil in the sump has dropped to a dangerously low level (which may be due to an oil leak or abnormal oil consumption by the engine.) This warning means the oil level needs to be topped up and the warning will stay displayed until you top up the oil. Running the engine with low oil will cause expensive engine damage.
Since it is a 2 minute job, Oil levels should be checked fortnightly as a minimum, together with radiator coolant and power steering fluid levels, if you run the car most days each week as most people do.

It is possible for a warning light to remain displayed when the cause has been dealt with because there is a problem with the sender unit. However it needs to be established with alternative checks that the problem has been fixed before investigating if there is a problem with the warning light itself.

any time a warning light comes on there is a problem that needs to be checked out. you don`t say what warning light comes on, oil light, check engine light, coolant light.

Pull up the error codes and freeze frame data to interpret the check engine light illumination.

Yes I would say the oil pressure switch is faulty. The oil pressure gauge uses a different sensor, so if the gauge did not drop but the warning light came on, I would have the warning light switch checked. If the warning light comes on, the fuel pump will stop getting power and you will lose fuel pressure too.

Yes it may be the wires are shorting or its actually the problem with instrument cluster.
Also get the vehicle scanned for any error codes stored in computer this will confirm whether is short circuit issue or actual problem:------
I suggest you few help links with accurate solutions to refer/go through:----Click the link below:------

Battery and brake Warning lights on Dash
http://alltypesofpartsreplacing.blogspot.com/2012/10/battery-and-brake-warning-lights-on-dash.html
--------------2002 Ford Windstar: Brake Warning Light ON dash? http://schematicsdiagram.blogspot.in/2012/06/2002-ford-windstar-brake-warning-light.html
-------------ABS & Brake warning lights remains steady on dash? http://schematicsdiagram.blogspot.com/2011/12/abs-brake-warning-lights-remains-steady.html
-----------Chevrolet Tahoe Hood open warning on dash and alarm sounds? http://schematicsdiagram.blogspot.com/2011/12/chevrolet-tahoe-hood-open-warning-on.html
-----------2005 Chevy Impala: Service Vehicle Soon Warning Light? http://whoisbyme.blogspot.in/2012/06/2005-chevy-impala-service-vehicle-soon.html -------------- Malfunction Indicator Light ON http://whoisbyme.blogspot.in/2012/06/malfunction-indicator-light-on.html
-----------Car Runs Fine But Check Engine light is ON?

http://whatisbyme.blogspot.in/2012/05/car-runs-fine-but-check-engine-light-is.html

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Check engine light with codes P2195 and P2197?

http://howtobyme.blogspot.in/2012/01/check-engine-light-with-codes-p2195-and.html

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How to Read Codes from Check Engine Light? http://schematicsdiagram.blogspot.com/2011/12/how-to-read-codes-from-check-engine.html
-------------These will help.Thanks.

That's an engine warning light. The other is a tyre pressure warning light.
You will need an OBD2 scanner to read any engine trouble codes.

Probably nothing whatsoever to do with you checking the dipstick. On the golf when the warning light flashes, you reset it by opening the bonnet. That is why you think that when you check the dipstick it resets, when in fact it was opening the bonnet. Check your bonnet switch

You can disconnect your battery for 15 minutes or pull the fuse for an ECM or PCM fuse, but the best way is to visit any local repair shop. Most shops will have a universal Check Engine Light Code Reader that can quickly and safely reset check engine light trouble codes. It should take about 30 seconds.

Ask your local service center if they could reset the check engine light with a Check Engine Light Code Reader.

Usualy the check engine light reports a malfuction in your engine performance system, it coulb be a misfire, bad sensors, vaccum leak, you need to have your engine code read from a garage or an auto parts store that offers the service for free.