Easy mate, and a straight swap works perfectly, the ecu is two bolts in the engine bay and a couple of multi plugs
as for the 5as, it can be a pain, you need to put your hand right up behind the dash, it is a black box held in by two bots and 2 multiplugs, the bolts are either 10 or 8 mm, i can't remember which lol
Unbolt them and wobble it out of place
Tom

 

ok thanks, i ddnt think of askin you!! lol

do i need to disconnect bat or anything? reset anything etc?

SJ

 

lol no probs and yeah, disconnect the battery and when you are resyncing the fob you need to plip it 4 times or so

 

Has your ECU been matched to the 5AS or are you swapping that too ??

 

Hi,

My son's central locking has also ceased to function and, after a certain amount of investigation, I suspect that I have the same problem. As a newcomer to ZR's, I'm not familiar with some of the terminology you have used. I obviously know about the ECU, but what's a 5AS and where would I find it?.
It sounds like I have to replace both the ECU and 5AS - is this correct?, and does the key fob have to be matched to one, either or both of them?.

Thanks, Steve.

 

The 5as controls the alarm and immobiliser, the 5as, the ecu and the fob are all paired/coded together so that they talk to each other.
1999-2003 the 5as is above the peddals on the drivers side, 2003 till end of production the 5as is mounted behind the heater blower motor of the passenger side. the shape of car ie facelift does not denote were it is.
I have a 2004 and it is above the peddals as they all are from 1999, yet I have a 2003 which is behind the blower motor, which was later model cars. I think it depends on the manufacturing dates.

 

post 2004 models (facelift) don't use the 5as system, and I thought it was the 45 and mg f etc where it is behind the blower motor

 

I stripped a 2003 25 last week and the 5as was behind the blower motor, on the 45 the 5as is behind the centre consul.