XC90....New Project

[2Diesels]

Well I made a rash purchase last weekend whilst visiting one of my favourite scrapyards.
I had been on the hunt for bits for my 850 & Rover 75s when I spotted what appeared to be a fairly presentable XC90 D5 Ocean Race auto.
I made enquiries & was told “it drove in” so I borrowed a battery & fired it up, it started without issue & sounded healthy enough. There was however a transmission warning on the dash. Anyway a price was agreed & home it came........very slowly, as soon as I tried to accelerate an engine warning message came on & it went into limp mode. It would reset by cycling the ignition, but would come straight back on.
I read the faults off it & there were a few engine related historic faults, I cleared them off & interrogated the transmission, to find one error relating to torque lock up. This error cleared straight away, so I reset the counter & ordered some fresh fluid. A road test was very successful, with no messages returning & no limp mode.
It has a strange twitch to the steering, which I’m pretty sure is down to it having the wrong fluid, as the feed hose from the reservoir to the pump had been cobbled with a bit of heater hose & the system topped up with red ATF.
I have a replacement hose & will buy some CHF this week & flush it through.
Other than that it seems pretty good, the body is pretty tidy though the interior is rancid...........or was until today.
It is fitted with the sat nav that pops up out of the dash, with the drive under the passenger front seat. It all seems to function but there is no disc. Now I don’t really use sat navs as I prefer a map, but I would like to get it working. Can anyone advise which disc I need? I have looked on eBay & am a bit puzzled.