I have some interesting information that I would like to pass on to the board regarding my experience with the dreaded alternating brake failure lights.
I have had a reoccurring issue with the brake failure lights alternating at the 1 HZ interval for the past several months. I had tried various things to resolve the problem. All the while the brake fluid reservoir that are readily accessible were totally full, and a computer diagnostics indicated that the brake fluid was low. The following are the things that I had done (up until yesterday) and the outcomes:
1) Replaced Front Brake Pads - The brake self-test passed for several thousand miles of use until several days ago. Though the brakes seemed to work properly, the 1HZ alternating brake lights returned.
2) Checked both reservoirs again, they seemed fine. But added a little fluid anyway.
3) Checked the switch underneath the rear brake pedal to determine if it operated normally. It did.
4) Traced the ABS sensor wire down and identified that the cables were not too tight, corroded, or stressed in any way.
5) Examined all pads, calipers, rotors, and brake movement to insure proper activity. All looked fine.
Honestly, I was stumped.. I knew that if I took my bike in to BMW, it was going to cost me a fortune regardless. So, I opted to take the high road:
1) Research Articles, primers, videos on how to disassemble the bike and expose the ABS control unit and go from there.
2) Between myself, my nephew helper, and my great buddy Wayne, we disassembled the bike, removed the fuel tank (not as bad as I thought), and started to inspect the fill reservoirs for the front and rear brakes. We found the problem !!! The front circuit on the abs unit was empty !!! No fluid at all.
We filled the reservoir up with a sipping straw slowly. We also examined the cables leading to the front brakes and found that there was grit on the area above the front wheel where the cable has a transfer screw on each side to a second cable that leads to the front caliper. One of the bolts was loose. So I tightened up the bolt. This may have accounted for some of the loss of fluid.
I then contacted the BMW dealer that did the last flush on the bike (which of course I paid full price for) and was advised how else a leak could have occurred. He also admitted that he may not have filled the reservoir up enough, during the last flush. That also could have contributed to the problem as well. I was further advised that if the bike had fallen over, brake fluid could have drained out of the drain vent.
So, there you have it. Upon filling the fluid, we turned the ignition on and the alternating warning failed to appear. So we then, reinstalled the fuel tank, started the bike (allowing it to go through the self test as much as possible). Only the single brake warning came on (normal of course). Once the bike was back together, I took it for a test drive. No Warnings at all.
Another buddy Greg, brought over his GS911, ran the tests, cleared the warnings, and the GS911 showed no other warnings.
Hopefully the problem is solved.
For those that have a similar problem, please be advised that the following links and information proved to be extremely beneficial at enabling my team to resolve the problem with no ABS brake experience:https://www.youtube.com/watch?v=TpI05pWUp-Yhttps://www.youtube.com/watch?v=Etex4BpLSKM
http://www.ukgser.com/technical/nick/Brake%20bleeding%20%28All%20BMW%20EVO%20systems,%20%2704-%2707%29.pdf - This doc has most of what you need if not all.
Without the information above I would be at the mercy of the dealer.
I wish to thank this forum and all contributing members for your help.
This place is an incredible resource !!!