I also ordered the rear door panel harness that should accommodate the additional speaker for the HK system. Like most parts for Volvo, it seems these are also on back-order, so TBD on when they’ll be in. I did however also order the correct screws and washers, so when installing the B&W speaker everything will be mounted up just as it would have been if it had been ordered that way.
In poking around in VIDA for the three reference cars I did come across a few things, some good, some odd, and some are unknowns.
The Good:
- The IHUs between the B&W and HK car are the same. So there’s no physical/hardware limitation there.
- The front door wiring harnesses for the B&W and HK are the same. [Though that makes it all the more weird that I had the strange loss in mid-frequency sound (proximity sensor beep) when all I did was swap in the B&W amp. I have not swapped it in again since I swapped in the B&W speakers, so maybe I should try that. Or maybe the amp just needs a software refresh/update. More on that below].
The Odd
– VIDA’s information on the part number for the B&W amp is confusing, and potentially conflicts with what is widely shown on most web-based part houses. In VIDA for MY19 a car with B&W is shown to use part number 36012657 [which is the amp that I have]. BUT…in the description it lists that as being used UP TO a certain chassis number which clearly pre-dates MY19. That’s also what’s reflected in online parts house descriptions. But here’s where it gets weird. In VIDA if you put just that 36012657 part number in it returns all MY19 and newer cars as applicable options. If you put in part number 36003118, the amp part number where the description says it’s for cars BEYOND a certain chassis number, it returns MY18 and older cars. So….I’m thinking that Volvo has messed up the descriptions for these two part numbers. It also would doesn’t make sense to me that Volvo would have a later iteration of a part, but give it a lower part number, when it doesn’t do that anywhere else that I can see. (see example of the superseded HK amp part number).
So what’s the physical difference between these two B&W amp part numbers? Does it impact performance? I don’t know the answer to either. One thing I do know is that a friend with a MY18 V90cc, with B&W, has a status light just to the left of the MOST connector on the amp. That is not present on the B&W amp that I have, and otherwise all the connectors and wiring are the same.
– Rear door panel harness. So this one is a real head scratcher. In VIDA it shows that the part number for the door harness attached to the rear door panels are the same between the B&W and HK car. Except they’re not. In fact the part number present on the two harnesses on my rear door panels do not appear to exist anywhere in VIDA. Like at all, for any car, at any point in time. Not that it was superseded at any point, or anything, they just flat do not appear in VIDA. The harnesses on my car are, left side: 32218505 and right side: 32218506. Compared to what VIDA says should be there, which is left side: 31678592 and right side: 31678594.
I mean…maybe my later revision harnesses numbers didn’t make it to the VIDA programmers to upload in their reference lookup. Or more likely, Volvo opted for some production cost cutting by having an HK set for the manufacturing process (the door panels are sub-assemblies made in advance), but then opted to save money for stocking/warehousing purposes by listing the shared HK and B&W harness part number in VIDA, since it’ll work for both.
Unknowns
– AUD reload. In the suite of parts associated with the different amps (which Volvo refers to as the AUD), there’s a software part listed as part number 31489264. It’s unclear to me what this would actually do. In VIDA you can see the existing software associated with either the B&W or HK AUD, and none of them match this part number. So what does this ‘reload’ do? Does it reflash the AUD and IHU and install the appropriate software based on the AUD that the IHU sees? In which case, is this the key to getting the B&W version of the Sound Experience app onto an HK car (or a base stereo car)?
Before everyone says, “but Volvo has a server of what the car came with and won’t allow that”, I’m not so sure that’s true. What it looks like to me, and how the car, VIDA, etc., interact, it’s that VIDA looks for what’s on the car. It does a hardware/software ‘inventory’, if you will. VIDA then applies updated software for the hardware it sees. Just as when you add certain accessories that require additional software for other components, when VIDA is connected, the new hardware/accessory is recognized on the bus and VIDA notifies the tech that “hey, you want/need to add this software part number”.
Either way, this aspect remains a bit of a mystery to me, and would need a willing tech to spend some time seeing what VIDA says once a car is hooked up with a different AUD than it was delivered with. That, or I need a proper battery maintainer so I can test it out myself. 
Probably end up being cheaper to do the latter.