If you brought an Pioneer aftermarket head unit for your car, like the Pioneer AVH-Z3000DAB and attempted to complete a Firmware Update / Upgrade you may find the option is Greyed out, like other various system options like Calibrating the Display or performing a Factory Restore. This is due to a "safety" feature in the unit which requires you to have the car parked. If you installed it yourself you may have noticed a cable for the parking break with a long lead. The old trick use to be to just attach this to a ground and the unit will think its parked. However Pioneer have put "security" features on it to stop this old trick and make it only sense a real parking break / hand break being pulled. So instead you effectively are left with two options - either connect it to your parking break / hand break cable or install a bypass. I know in my option of an old Ford Fiesta, I didn't fancy pulling apart all the cars official cabling and deal with that messing up so the easiest solution was to install a Pioneer Bypass which you can pick up on eBay or Amazon for cheap: UK: Amazon - Prime Next Day: https://www.amazon.co.uk/gp/product/B01NBTJTCY/ eBay (Cheaper, but mostly shipping from China): https://www.ebay.co.uk/sch/i.html?_...rksid=m570.l1313&_nkw=Pioneer+Bypass&_sacat=0 US: Amazon - Prime 2 Day: https://www.amazon.com/APPS2Car-Par...72&sr=8-1-spons&keywords=Pioneer+Bypass&psc=1 eBay: https://www.ebay.com/sch/i.html?_fr...neer+Bypass.TRS0&_nkw=Pioneer+Bypass&_sacat=0 The one I used was the UK Amazon Link. These units work by sending a 'pulse' every few seconds to the unit to make it think the hand break is indeed applied. Installation is really easy with the included guide, you just hook up the three wires into the device like I've done below: Once done, the devices full features will be unlocked 24/7, whenever the Unit is powered on. The side effect is other features like DVD Players also fully unlock even when driving. With all of these, common sense has to be used and local laws followed - it's fine for a passenger to watch a DVD but if its within view of the driver you may find yourself committing a criminal offence. This guide is provided for those of you who do not want to have to take about the cars official wiring just to hook up a sensor to let you do a Firmware Update or Factory Restore the Unit.