I've posted in the past about this issue with our 2001 Volvo S60, Brake Failure "Pull Over ASAP" warning light.

Since we live in a small town, I can't find anyone that has the knowledge locally to work on this for us. I just keep having to disconnect the battery, which is obviously a pain.

Someone gave me an idea for a short-term fix for the disconnecting battery issue, until we can hopefully get this fixed for good, if ever. It's been so long I'm losing hope. Anyways, here's the idea and I'm hoping someone will give some advice on whether this will work or even be a good idea or not. I was told to rig a switch to the positive cable coming off the battery that will in effect allow us to quickly simulate disconnecting the battery to reset the computer and erase the error, by flipping the switch off then on.

Any thoughts?

 

I might be telling you something you already know here, apologies if it is, but the most common reason for this fault is a cracked ABS ring, the toothed ring that fits on the end of the drive shaft just behind where it fits into the wheel hub. They eventually crack and the sensor reads this as a fault.
They cost around £20 a pair on the internet, and are reasonably easy to fit. It happened to me, my local mechanic scanned the ABS, found out which side was broken, pulled the hub off the shaft and fitted a new one. Problem solved.