Management light is on

[Goleki200]

management light is on and code is coming 

3 piston misfire 

what does it mean ?

or what shall I do

[kithmo]

Check the connection on No.3 coil, if the connection is good then the coil could be faulty. I doubt if it's a spark plug as they don't always throw a fault code up.

[unclepoo]

I had a similar problem to yours....mine was a miss fire when the ice started, though never got as bad as throwing up a fault code.

It turned out to number 1 coil was wet through, rusting and starting to come apart.

To check your coils, remove the engine cover, you`ll see the 4 coil tops, number 1 is on the drivers side. unplug each coil connection, they are tight so I squeeze the release clip and ease the plug off gently with a flat screw driver if it wont come off by hand. Then use a 10mm socket or spanner to remove the coil retaining bolts. The coils can then be lifted out, though room is tight....a bit of wiggling is required.

Changing the spark plug can be a good idea if they have got wet...any signs of rust or if they`ve been in they for some time.

coil   http://www.ebay.co.uk/itm/2014-TOYOTA-VERSO-PRIUS-1-8-VALVEMATIC-VVTI-PETROL-COIL-PACK-X1-2009-2016-/302167966618?hash=item465a9d439a:g:LegAAOSwJ7RYU-Es

plugs  http://www.ebay.co.uk/itm/4x-DENSO-IXEH22TT-IRIDIUM-TT-SPARK-PLUGS-FOR-TOYOTA-PRIUS-1-8-Hybrid-04-09-/152476769923?hash=item238052de83:g:Yf4AAOSwhQhYzUdD

I`m assuming you have a 1.8 prius or auris hsd