Hi,
I bought an 2.1 x type a few months back, the engine was replaced prior to me purchasing it.
I drove it home over 400kms without a problem.
I went out the next day to start it & It wouldn't turn over. I searched for issues relating to tcm to ecm since it comes up gearbox fault & that was the code that it was throwing when we had a diagnostic machine used on it.
I have gone ahead & replaced the tcm, the ecm with new dashboard, key fob & a new full sized battery & it still wont start.
Is there anything else I could try before I bite the bullet & take it to the mechanic?

 

If it wouldn't turn over you should check the starter or the battery cables.

 

I've checked the cables & they're clean.
The starter motor is fine.

 

 

You might want to try the immobilizer and reset it. Also if you have change the modules and replaced the instrument cluster with out programing you may have set the vehicle into anti-theft mode.
The immobilizer is like a circuit breaker. It is located on the right side panel in the footwell behind a trim cover on the body side of the vehicle. You press down on the button on the top to reset it.

 

I had a similar issue like a year ago, turned out to be a bad instrument cluster. Replaced my instrument cluster and reprogrammed the key befor my Jag came alive. NB mine also threw up the gear box warning light.

 

One other thought that I found mine has. At low fuel (mine showed 57, 90 & 95 miles on range and between 1/4 & 1/8 on fuel guage) the duel system fuel pump is SUPPOSED to electronically "switch over" to draw fuel out of the reserve saddle bag type fuel tank and illuminate the low fuel dash light (which by the way illuminates on key on, start up & extinguishes), mine has a problem with that transfer. Light does not illuminate, car won't start. Dump 5 gal of fuel in, fires right up. Asked the Jaguar dealer what side of actual fuel pump or sender unit is not functioning, they said "don't know". Which side is the smaller "reserve" saddle bag fuel tank side, again "don't know".

So I just hit 100 miles on range and fill it up, lol.