red light on dash flashing and key messing around MK6 Fiesta

Morning all, 

i have started having a problem on my fiesta, it started off just a random thing every now and again where the key when you  turned on the ignition the red light would flash rapidly but then try again and the car would start, but over the course of 4 or 5 months its gotten worse to the point where it started cutting off when the engine is running,  sometimes it takes 5 mins of messing around to get the engine started.

i bought an ELM 327 and the error codes it gave was

Hi all

B1681 PATS Transceiver Module Signal Is Not Received  

b1601 PATS Received incorrect key-code from ignition key transponder 

Any idea how much this will be to get sorted and can a auto electrician sort it out? the 2 keys are the original and both have the same problem. i have tried both keys and its the same problem i have taken off the plastic around the steering wheel and taken out the connectors and plugged it bag in same problem is there anything i could try. oh the battery is 6 months and is fine.

one last thing when you turn the key the window wipers come on for a couple of seconds etc it's weird.

any help or tips greatly appreciated 

Deano