you now will ask what the maf is
the maf may stand for mass air flow.. or something like that.
Its the sensor in the air intake system that measures the air flow, or air volume entering the intake system.
If you look at the airbox that holds the airfilter, conected to this is a plastic pipe with an electrical connection on the back top of it. This is the maf.
If this fails the ESP warning light will come on the dash as you have, many wonder why you get this, but without this data the traction control doesnt work (i think) so in that respect it makes some sense.
You could test and see if the ABS or traction control is working. I suspect the ABS is working but the traction control not. (maf)
If it is the MAF you can replace this yourself, its a very easy job, although it will set you back about £85 on an exchange basis from a
dealer. You can get them a little cheaper from GSF and places like this. (and the part number is important as there are variations)