There's nothing in the Wiki as far as I can see but there is something in the manual - tried it a few times. While I'm eating my McDonalds today (little treat) after having my first COVID jab I'll have another play.  Geoff

Not sure if this is what you've seen in the manual but this is the reset process.

Start the engine and run for longer than 2 seconds. Stop the engine and switch the ignition off.

Switch the ignition on, and then off.

Press and hold the on-off button for approximately 2 seconds, until the LED indicator lamp illuminates on the deploy-
stow button.

Press and hold the deploy-stow button for approximately 10 seconds, until the electrically deployable tow ball has
reached the fully deployed position. A double warning tone sounds to confirm.

Release the deploy-stow button. The electrically deployable tow ball is now reset. Current Fleet:-
2018 Discovery 5 3.0 HSE
2021 Ford Ranger Wildtrack
2019 Ford Mustang Bullitt 5.0 V8
1993 Defender 90 200TDI Pickup

Gone - not forgotten
2016 L405 4.4 SDV8 Vogue SE
2012 L322 4.4 Westminster
2004 L322 4.4 V8 Autobiography LE
2000 P38 RR 4.0 HSE (ex Clarkson test car)

Thats what it says in the manual and I've tried it a few times to no avail. However inspired by you and Craig taking the trouble to reply I just nipped out and tried again - Voila - it worked.

There is nothing in the Wiki and my IDTool didn't show any faults but now I've got it deployed I think I might just leave it out for the time being so I can connect my C-Tek without opening the bonnet  Geoff

Hi Geoff - there is a known issue with some of the original towbar electrical modules. Might be worth checking because the newer module can be found on ebay for about £25.

If you find the module, which is on the right hand side of the boot in the spare wheel well recess - there is a small rectangular flap - if you open this, you'll see the black rectangular module - check the last two letters on the part number printed- if they are AF then it may be worth finding an AG or AH module which have updated software in them.

And apply a good amount of copper grease to the towbar screw

The other idiot feature that kept getting me as well is you can't deploy the towbar with the engine running - caught me out a few times - but I'm sure you know that already.

Hope that helps
Cheers
Nick Current Fleet:-
2018 Discovery 5 3.0 HSE
2021 Ford Ranger Wildtrack
2019 Ford Mustang Bullitt 5.0 V8
1993 Defender 90 200TDI Pickup

Gone - not forgotten
2016 L405 4.4 SDV8 Vogue SE
2012 L322 4.4 Westminster
2004 L322 4.4 V8 Autobiography LE
2000 P38 RR 4.0 HSE (ex Clarkson test car)

Thanks Nick - I'll have a look they seem cheap enough on eBay (lots of AG's). I haven't had a look at mine yet, too cold. Geoff