flashing immobiliser light wont stop (help!)

[danny_stoke]

hoping to get just some quick advice about my 172 cup 2003?

first thing happened the flashing light fault on the immobiliser wont stop flashing..

rac came out and checked all relays next to the battery.. says its key transponder

takes me to a small renault garage (not main dealer)

they do diagnostic comes back key decoder.. so i get one myself and try nothing happened..same flashing.. they try coding a new key.. same fault key decoder

so i buys a by-pass from a guy 113 pound.. same flashing light.. so the guy i bought it off comes to check and i get a refund.. he also says its the uch and it f**ked??

so any advice from here would be so appreciated its untrue.. do i need a new one.. how hard is it to fit a used ecu/uch etc myself.. could it something so simple like an earth?? the guy said my car is a right off! ust paid 3 grand 6 months ago for it :-(

 

[The Boosh!]

 

[danny_stoke]

thanks theboosh couldnt find were to start it

 

[VXR killer]

dont you have to recode the key/reader when you replace either

 

[danny_stoke]

yes i was there when they tried to do that..
but the guy who sold me the by-pass said it wasnt the key or reader or his thing would work??

 

[Beef-Mc]

Are we talking about the flashing red light in the middle of the dash? Is it doing it when you're driving or just when the ignitions off?

 

[danny_stoke]

Are we talking about the flashing red light in the middle of the dash? Is it doing it when you're driving or just when the ignitions off?

the car wont turn over and start.. the light just keeps flashing!
sorry i didnt mention that in my first post

 

[danny_stoke]

well ill post on here what the problem has been.. the guy at endon renault garage says a guy might be looking at it for a diagnostic tomorrow afternoon.. i pm'd a guy on here and he says to check all fuses/relays on the uch and then maybe try a reset of the uch..
i phoned endon garage and told them but have heard nothing back.. i really wouldnt recommend them to anyone and wish id had my car taken to madeley heath motors (renault) stoke instead.

 

[danny_stoke]

update on what the auto electrician for renault says was the problem has been.. apparently something has been corrupting the key/code in either the uch or the ecu.. with not being able to find out exactly was recommended to get a new uch/ecu kit from a breakers as the cheapest option.. i went to w b breakers in cheadle staffordshire they deal in breaking all renault sport models and had this on the shelf for a cup and loads others too only £100 too good value!
so hopefully ill get the call tomorrow that its running again.. fingers crossed