It isn't uncommon for '06 12X's to have the fuel pump wires eventually wear through inside the frame. The loom running to the fuel pump and the low-fuel sender didn't have any covering and run the bare wires through an aluminium bracket that has sharp edges.
The wires are very tough (feel like Teflon but I don't know that for a fact) but eventually wear through.
If you are unlucky enough for the first wire to wear through to be the pump power you will get intermittent fuse popping.
If it is the return wire for the fuel pump you might notice the pump intermittently doesn't turn off a few seconds after you turn the ignition on.
If it is the low fuel sender you will get false low fuel warnings.
The picture isn't the best and reducing it to fit the forum has taken its toll as well.
If you look at the wires at the L/H end of the aluminium bracket you can just see a nick worn in both the grey and the red/yellow wires. I was lucky and noticed the pump running on when the ignition was switched on and repaired this before it left me stranded. The power wire was so close to wearing through to bare wire it was scary.
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The replacement loom for the pump comes with a protective covering over this loom where it runs through the aluminium bracket and I believe earlier XB's had this covering. I don't know if this penny-pinching exercise continued through the '07's etc.
You might have an issue elsewhere in the wiring for the fuel pump but this one is a stinker if you happen to experience it and from what I saw with mine I would strongly recommend an inspection - particularly if you knock up the miles (mine didn't show up until 75,000km).