Help with ABS Fault

[Billerbeck]

About a week ago the General Warning Light came on solid and the ABS Warning Light came on flashing at 4 Hz. Per the owner's manual this means at least one brake circuit in Residual Braking Function Mode. I can hear the pump when I apply the front brake lever and the bikes stops hard (just as normal). If I step on the rear brake pedal alone there is almost no braking force whatsoever.

Initially, I could clear the fault by cycling the ignition off and back on. And the fault would only occur about once in a thirty minute ride. As the week wore on the fault became more frequent to the point that the fault is always present now from the time that I switch the ignition on.

I have checked the normal stuff (tail light filaments, fluid reservoir levels, brake pad wear, etc.) and found nothing out of line.

Any help would be greatly appeciated.

[socalrob]

I'd check the following:

1 - Battery voltage is critical. Even though the bike starts fine the battery voltage may be off enough to cause some fault(s) with the ABS. I'd get a new battery.

2 - I seem to recall some bikes having sticking brake switches at the rear pedal. Of course this could have combined somehow with a weak battery.

3 - I've been told the brake fluid levels are critical. If the bike has been on its side you can loose some brake fluid from one of the rear systems.

I'm picking up a new battery myself tomorrow. I've been riding around with the little fault light on for a week or so. Bad battery voltage.