Hi Withy
Yoda from Darwin here, we have the same issue with our GC ( on two occasions)
I found on one of the us forums a good description from a guy with a V8 GC, but did not save page and now can't find it again, they were talking about fuel pump and keyless entry module.
Here is what happens to me
Push start button, engine starts and runs for about 1 or 2 seconds then stops, as it stops a red lightning bolt shows in the MIL then the oil light comes up, if you try to start it again and same thing happens, the brake pedal gets very hard, can try this 5 or 6 times and same result
What I have been doing is turn it off get out lock it and walk away ten meters or so then then come back and go through start procedure again, some times it works first time, I have had it take up to three times.
First time it happened, once it started again, I took it straight to the dealer and had then check for codes, they said there were none ( but it is Kerry's in Darwin ).
I have since found this
http://www.wk2jeeps.com/tsb/tsb_wk2_0802411a.pdf, but the problem has not happened again for me to try pulling fuse M27, I hope this will work as then there is a known fix
I am leaning towards the keyless entry module as the act of shutting down and locking the car would reset its tiny brain, and this seems to be working for me
Give the fuse pulling a go if yours stops again and let us know if it works, I'll post if it happens to me
I also find this helpful
http://www.wk2jeeps.com/wk2_tsb.htm#NEW, doesn't always apply but gives you an idea and puts the dealer on the right track
Cheers Yoda
Sorry for the novel