Hello,
My Check Fuel Filler Gap light is on (2009 XF Supercharged). I had a new DTML pump put on a few weeks back--and I have a new Jaguar Gas Gap--from an authorized Jaguar Dealer, so why would the "gas cap" light come on?

 

just a guess but recall a gent on the X350 forum who had a gas cap error code. Turned out the cap retainer plastic was preventing the cap from sealing properly. In any event, check the seal.

But also this from the threads below:

https://www.jaguarforums.com/forum/x...r-cap%22-5349/

 

Welcome to the forum kenmicn,

I've moved your question from General Tech Help to X250 forum. This is the place to post technical questions about your model.

Graham

 

>Turned out the cap retainer plastic was preventing the cap from sealing properly.
I had this exact problem with my S-Type. Every year or so the gas cap light would come on. I had my local mechanic take a look but cause was not apparent. So I just decided to replace the cap with an OEM one. That ~$30 brought me peace until it happened again...
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Jaguar: Grace, Pace, and Space - Sir William Lyons
Current: '15 XF (X250) Portfolio AWD 3.0 (it's aubergine)
Past B: '08 S-Type 4.2 "Satin Edition" (250.06 whp / 259.67 torque)
Past A: '05 X-Type 3.0/auto Jaguar Racing Green