1Hz blinking ABS and General Warning Light
So I've had my '04 K1200GT for a couple of years and, on the whole, it's been fun. I have the cold idle problem and my battery trickles flat every two months but you get used to it/if you want no problems don't ride a 14 year old bike with 55,000 kms on the clock!
Anyway: today I get the bike out and ride away. Within a few hundred metres the ABS warning and the General warning light begin to blink alternately at a rate of about 1Hz. I pull over and stop. Turn off the engine to see if it's just a bug, but it isn't and the lights come back on when I reignite the bike and move off. Do a brake check - they seem to work just fine - as does the ABS on the rear (a quick stamp on the pedal to check that -I'm not brave enough to test whether the ABS is still working on the front). I ride perfectly OK to the office about 10 km away (because I keep the bike's papers there because otherwise the missus would move them and then deny all knowledge of their new location). In the instruction manual trouble shooting guide on page 81 of the manual it says that this is caused by "Level of ABS cooling liquid being too low" and suggests checking the pressure and effectiveness of the brakes with the ignition off. When I perform this tests the brakes seem fine both front and rear and I also check for leaks - of which none are found. The instructions say that if the results of these tests are negative the "braking system is defective". The ABS System was purged front and rear at the 50k service about 5 months ago.
TD;DR: ABS and general warning lights have come on but everything seems fine.
1. Has this happened to any of you?
2. Does the ABS system purge also do the cooling system? (Because if so I'll be having words at the BMW dealer that I have it serviced at)
3. If it has happened to any of you, what caused it and how much did it cost much to fix?