To make it clearer, think the Zimmermann Telegram but with Britain instead of Germany.
No, that was already obvious. The point was that although the Zimmermann telegram was incredibly stupid, it still had some kind of logic since the US was Britain's biggest trading partner, since by 1917 the US was decidedly pro-Entente, and since the point of the Telegram was that Germany had decided to start up unrestricted submarine warfare which the US was not real cool with (we know this is the point of the Telegram since the Telegram says so).
To reverse all that and give a similar incentive to the Brits, you need a POD that is probably pre-1900. Add in also that British diplomacy tended to be less incompetent, at least as regards the US, which as a naval, Atlantic power had mattered to it for much longer and which it had taken much more of an interest in.
But if ASBs somehow magically had the US come in on the Central Powers side, its grim for the Entente and they might try a negotiated peace. Financing and trade to Britain and France are cut off, there is a lot of land warfare between the US and Canada, and the Atlantic becomes much more dangerous for shipping and sees a lot of naval clashes, but neither the US nor Britain are strong enough to blockade the other. Nor do I see a big decisive naval battle unless the British get desperate (possible) or the US gets really stupid (less likely).