Hello all, I have just discovered your forum and amazed at how much info is on here!!!! I've done some searches but couldn't find exactly the info I was looking for - at my wits end here. If someone can answer this I'll be extremely grateful.

At the state inspection the emissions test couldn't be completed because the computer couldn't communicate with the OBD port- the inspector said it's common that the fuse is blown, and is also the same fuse as the cigarette lighter. Checked the cigarette lighter, doesn't work either so makes sense. Only problem is I've checked dozens of digrams, fuse lists, pulled about 10 fuses that were supposedly that one and they were all fine. The car didn't have the original manual with it when I bought it.

So before i resort to pulling every fuse in the thing - does anyone have a definitive answer for which fuse is for the OBD port/Cigarette lighter on a 2009 XJ8 4.2??

Thank you, Kerry

 

The owners manual gives F43 and F16 in the cabin fuse box (footwell) for diagnostic connector.

You can get a digital owner's manual from Topix (https://topix.jaguar.jlrext.com/topi...bWBkK.prs72697) and paper copies from https://www.jaguarlandroverliterature.com/jaguar/

 

Also, much info is on JagRepair.com - Jaguar Repair Information Resource

 

Sometimes the fuse appears to be ok but is faulty.

I suggest you replace the fuse.

My electronic manual says diagnostic port is F43 cabin fuse box.

 

It worked!! Changed F43 out and the diagnostics machine worked fine - thanks a lot guys, really dug me out a hole!