There seems to be loads of questions in reference to punto (188/mk2) steering columns,hopefully before anybody posts,yet another thread,on this I can answer your question(s).

Firstly the car must be taken to a dealer to get the codes read from the steering ECU.DONT IGNORE THE STEERING WARNING LIGHT,yes it might have gone off for now but that is no excuse to forget about it,drive first not just your but others aswell!
If you dont have any warning lights but the steering feels 'vague' especially turning either left or right or the steering wheel is turned but the car doesn't respond quickly enough then get the car to a Fiat dealership,this will also probably need a column,even though errors are not logged,a good Fiat technician will be able to determine this.

If your steering light has/is on it might not be steering column related,a faulty vehicle speed sensor (or sensor wiring) fault will bring on the light it may also bring on the engine warning light & even stop the speed from working.A error code (P0500) will be logged in either the steering ecu/fuel ecu or body computer.
If this is the case a wiring modification (carried out by dealer) from the speed sensor to the fusebox can be carried out...problem sorted.
It is also worthwhile checking the connectors are 'sound' on the steering ecu as there have been reported cases of loose connectors/wiring in this area.

Low voltage problems (get your battery tested correctly) can also bring the warning light on especially at 'start up',often on colder mornings,again intermittent low voltage errors will be stored in the EPS ECU.

The error you dont want is 'motor posistion torque sensors' this simply means you need a column & thats the end of it.You cannot replace the sensors & they are not a part of the electric motor assembly.If your car is under warranty fine,you have nothing to worry about.Third year warranty does cover this but make sure you have up to date service history or forget it!

However if it is out of warranty then you need a complete column.You cannot get the column parts seperate,this option is only open to dealers while the car is under warranty, not the general public at time of writing.

If you are planning to buy a column secondhand think very carefully,it is well reported that 'faulty' columns are being resold.If you supply a column that you get a Fiat dealer to fit/or calibrate & it's faulty you will still be charged for fitting/calibration!
When a new or secondhand column is fitted it must be calibrated by a Fiat dealer there is a small charge for this and therefore must be taken into consideration when buying secondhand.Likewise if the steering ecu itself is faulty this must also be calibrated by a Fiat dealer.

One bit of good news is punto steering problems are becoming less frequent so if your buying secondhand you should be ok but it might be worth getting errors read to save you a hefty repair bill and enquiring at dealer if any part of the EPS has previously been renewed.It is also known for puntos to have no steering problems but ask yourself why is the seller selling the car....could this be a reason why? £550-650 is after all alot of cash!