Monday, May 23, 2011

Troubleshooting

abs indicators

I rolled my 2003 BMW K1200GT out of the garage yesterday afternoon because it was blocking access to the lawn tractor. After mowing, I put the tractor back and decided to take a little spin down to the post office, ostensibly to mail a Netflix movie, but really just to have a little ride on a pleasant afternoon.

Under normal conditions, the #2 warning light glows red until the bike reaches 3 mph, then it goes out, signifying that the computer has run its diagnostics on the Antilock Braking System (ABS). This time, however, the light did not go out. It began flashing in alternate sequence with the #1 warning light (ominously named “Brake Failure”).

WTF? The ABS computer failed on my 1992 BMW K100RS several years ago and, had I not enjoyed a cordial relationship with my dealer, it would have cost me well over $1,000 to replace. Was I looking at a repeat of that horror show?

I turned the possibilities over  in my mind as I rode to the post office. Once there, I switched off the ignition in the hope that all would be right when I switched it on again. Nope, the two lights continued their alternate blinking at a rate of 1 Hz (1 per second).

Maybe it’s trying to tell me one of my turn signals or brake lights is out, I thought. But just to be sure, after I turned off the highway onto the paved county road where there was no traffic, I jammed on the rear brake and felt the reassuring chunk-chunk-chunk of the ABS. But still the lights blinked.

I pulled into the garage, dropped the door and in the semi-darkness confirmed that all of the signal lights were working.

OK, check the Rider’s Manual. I found a troubleshooting chart on page 81 that included my symptom:

abs diagnosis

The brake pressure is OK at the levers and the brakes are functioning, fore and aft and there is no sign of leaking brake fluid.

I checked the front brake fluid reservoir sight glass on the right handgrip, with the bike on the centerstand and the bars turned full left, like it says in the repair manual. The level was right on the center dot:

abs front resHowever, when I inspected the rear brake reservoir, I found the level was just a smidge below the MIN(imum level) marker:

abs rear res

Oho!

Checking the work order from my bike service last month at Grass Roots BMW Motorcycles in Cape Girardeau, Mo., I confirmed they replaced the rear brake pads and brake fluid.

My possible conclusions:

  1. The technician didn’t put enough brake fluid in the rear reservoir, or
  2. The technician left something loose that permitted brake fluid to escape from the rear reservoir, or
  3. Something else I haven’t thought of or accepted – like the ABS computer going nuts.

At any rate, it is an apparent failure of a system that the technician at Grass Roots worked on recently and at the very least they owe me a brake fluid top-off and an inspection.

So it’s off to Cape Girardeau on the first sunny day to set things right.

No comments: