Again I'll say there is no NEED for pulling fuses. While that will keep the truck from lowering, the GAP tool will do the same and more. You CAN pull fuses, but why?
There is no worry about driving with the GAP tool plugged in. It's very secure and will not fall out, and while I'm sure you could somehow kick it if you tried, you could also win the lottery or be struck by lightning. None of these is likely. Further, it draws an extremely limited amount of power so not a worry, plus you would of course have the engine running anyway so it's few milliamp draw is of no concern.
I believe Enrique's issue was a simple matter of not knowing how to take advantage of the GAP tool. It's not super-intuitive. I know there were times I had it with me and could have sorted an issue but I didn't know how to use that that feature. For example, with rods on I had an error that dropped me to the bumpstops. I used the GAP tool to clear the fault so the truck could reset but on the stops the rods had driven one of the sensors out of range, so it was caught in a loop...clear the code to re-activate the pump to raise the truck to clear the code.... I got around it by jacking the truck up a couple inches with my hilift then clearing the codes. Had I been smarter about it I would have manually inflated the bags with the GAP tool then cleared the codes. Same effect, but without the manual labor.
Simply 'hotwiring' the pump to run WILL NOT inflate the bags. I've tried this on an LR4 (WRL, 3 years ago, Michel). You have to run the pump AND trigger the appropriate combination of valve blocks. It's easy to manually engage the relay for the pump, but until you also open the gallery valve and at least one corner valve nothing will happen. Again - if the hardware will work at all the GAP tool can manually command all of these things and you can force it to lift to whatever height you want. Then you can put the truck in 'build mode' and the EAS will not be able to control it...you will get an annoying gong every minute or two and a light on the dash because you have dissabled the EAS, but the truck will stay at the height you put it.
Knowing the fuses is a good back-up, but should never actually be needed for a field repair if you have a GAP tool and know how to use it.
We'll take some time and play with it on Saturday. It's pretty cool what it can do. Chad has been playing with his recently (does that sound dirty?) and is learning what it can do. Very handy.