Yes it assumed this aswell since the other car started just if the were the wrong way around it can really knacker the computers on the car.
You are right in what you say if the immobiliser is not working the fuel pump will not prime. You should hear a quick whine when the key is turned on as i'm sure you know.
The central locking function of the key is unrelated to the immobiliser function one can be faulty and the other will still work. Saying that though did the central locking stop working at the same time as the car stopped starting? Does the red light on the key flash when you press it? The unit which takes the signal from the key to operate the central locking called the
also operates the immobiliser so it sounds like you could narrow your fault down to this.
Go out to your car when you get a chance and put the key in the ignition. Hold the button on the end of the wiper stick that is used for going through the trip computer. Hold it in and turn on the key at the same time all the dash lights should come on does the red immobiliser light come on?
There is also the possibility it could be something simple like a blown fuse for the
. There is one fuse which can take out the immobiliser function of the
though I can not remember for sure if the immobiliser light would then flash or not light up at all as described. Open the passenger door and look in the fusebox you will see on the cover which fuse is which and there are three for
. Try checking these first for one that is broken and if not try and go through them all as there are some which are not labelled
but still control functions of it.
I have tried to keep it as simple as possible I hope i've made it easy for you to follow what i'm saying.