Was talking to a friend of mine today and he is of the opinion that if the new key has not yet been programmed, it will actually still crank the engine, but it will not start. I was under the impression that it wouldn’t even crank. Which is it? 
It will crank the engine
Oh boy … thanks … 
It’s not cranking, is it.
No, but I wonder if that is not b/c of the key, but b/c of that disconnected transmission linkage. Friend of mine got under there and we reattached it, per the manual. But, it looks like possibly the inner cable has to also be adjusted (“fine tuned”) to within tolerance (3-mm. ?) or the shifter will still think the car is in gear when it is really in park. Friend is working on that (possible) part of the issue now. And, btw, per a video on doing same on an X-308 on YouTube, the manual is correct in that the whole center console has to be removed to access the pair of locking adjustment nuts for the inner cable. 
Also had him swap out the starter relay to make sure that is not the issue. Wish I had a multimeter to see whether current is even going to the starter relay when the key goes to Pos. 2. 
Other than that (and assuming the replacement starter is good), no idea what would keep it from even cranking.
One thing my friend noticed was that someone had removed the panel on the left side of the driver footwell area (i.e. next to the left side of the left foot). There appears to be a big red (relay?) of some kind behind it, and I wonder if the previous tech thought that might somehow be at fault. ?
The relay is a good shout. I’ve had intermittant problems with it.
If the car think its in reverse (rather than Park), it really should put the reverse lights on, so move the shifter about and see if the rev. lights go on and off as expected. Also check the P lights up Red as this signal comes from the gearbox ECU.
What I did was remove the right wheel, to access the starter motor. Ensured it was in Park.
Got a large flat blade screwdriver and shorted between the 2 starter terminals.
Starter should spin over if its ok.
If its ok, then you need to investigate the relay. Remove the bypass and see if starter turns.
Or you could save alot of time and move straight to this step, rather than messing about on the floor
It is supercharged ?
This is a v8 x308 ?
i think that is what is does when the key isn’t programmed. It was a long time ago when I swapped in a replacement ECU and the car wouldn’t run (no surprise)
Funny you should mention that, and that is exactly what my friend said he is going to try today (the screwdriver on the starter trick) … btw, no, just a base model X-308.
Thanks, Andy … 
Did you ever get the X308 started and running?
Actually, just had to move Harlem (temporarily) to my office complex parking lot, as she had been red-stickered for tow off (along with Superblack) back at my former apt. complex 
. Have a storage slot to move Superblack to. I took Harlem’s battery to AZ yesterday for them to find out if it is still good or needs replacement (might be the case that my old crummy battery charger has finally bit the dust). Sitting for a couple of months I guess drew hers down to 0 charge. They didn’t call me last night to tell me whether it was bad, needed charge, or what, so on my way over there now to find out. As soon as the battery is in her and good, will have her towed to the mechanic to finally program the new keys.
One thing I learned about AAA when I tried to get them to handle the tow, you have to tell them your car just broke down on you, won’t start, etc. or else they will consider it a “tow of convenience” (their undefined term of art, apparently) and refuse to cover it. I was SO mad at them when they refused to cover either tow earlier this week, despite knowing my cars might get towed off involuntarily at any time. 
(see my thread on that subject in the Lounge). Learned my lesson there.
(thanks for asking btw, Motorupman ) …
Just a ‘heads-up’. The engine will NOT crank or start using a key that is NOT configured to the car!! I just bought a cut valet key from Autobahn Jaguar for one of my 2000MY XKRs and all the key does is turn on the ignition but NO CRANK, NO START.
It also set a P1260 in the ECM.
I have two master (black) keys but I wanted the full set that includes a VALET key. (just because)
Glad I have two WDS and two IDS computers so I can get this done today or tomorrow.
The cut VALET key was just under $80 with my trade discount.
Let me know how the configuration goes and I hope it runs.
Will do … btw, still no T.C. # P1260 on the OBD II, though … Not sure what’s up with that … 