Join Date: Sep 2016
Location: San Jose, CA, USA
ABS Warning Light - on solid
Recently picked up a 2008 K1200S with $30K miles. Love the bike but it is having the pesky brake failure light problem. When I turn the key on sometimes the ABS warning light comes up flashing and turns off as I drive away, and sometimes the warning light comes up solid "on", and does not turn off while I am riding. After the bike sites for a few hours or a day or two, it is a 50/50 chance if the warning light will come on flashing or solid "on".
1) Since when the ABS light comes on flashing and goes off as I ride away, I am assuming the ABS sensors (front and rear) are working OK. I did check the clearance on the front wheel between the sensor and the ABS sensor ring on the wheel @ 20 thousands.
2) I inspected the wires to both of the ABS sensors for any nicks in the attach system.
3) I don't see any wires or sensors associated with the brake shoes, but replaced them anyway because it was time.
4) I also bled the brakes and made sure the brake fluid containers were filled properly. Also I don't see any sensors associated with brake fluid levels.
5) The battery is almost new. It tends to hold its voltage around 12.2 - 12.4 volts.
6) Soooo....does that leave the ABS Brake Servo Control Unit? I do not understand the function of this device. I understand the valve body will distribute braking power to both the front and rear wheels, but when is the servo (motor) turning? I can't hear it running. I have a garage stethoscope but can't really hear anything going on in the servo. Does it spin whenever the key is on? Does it spin only in an ABS braking situation? I know they are expensive and I can disassemble to check the brushes on the motor, but I'd like to know there is a good chance that that is my problem before i rip into it.
Any counsel from someone with experience would be most appreciated.