Dear MOby,

What would cause the ABS light to intermittently come on then go off on an H-D Ultraglide? Or any bike? It was just serviced at 30k miles and started 10 miles away from the dealer. I called the service rep and he says that the wheel bearings are probably bad and to bring it in so they can work on it. New tires were mounted 1k miles ago. Something doesn’t sound right…

Paul Barnes

Hmmm, that does sound suspicious, but makes perfect sense if the front wheel came off during the 30k service. Unlike most ABS-equipped bikes that have external sensor rings mounted to the wheels, Harley lately incorporates its ABS sensors inside the wheel bearings – part #4 in the diagram below– mostly for aesthetic reasons we assume.

112116-ask-mo-anything-harley-davidson-absAlan Barsi, Harley’s Fleet Center Manager here in SoCal, says:

There are a couple of things that can cause the ABS light to come on:(1) The bearing is a possibility if the trigger inside it has become inoperable. (2) The ABS pickup/wheel spacer can go bad as well if the wire leading to the sensor has been pinched or cut [which seems most likely to us if it happened immediately after the bike was serviced].

Either of these should lead to a stored code in the ECM as “loss of speed reading”. If the ABS pump had actually failed, you’d expect a solid light and not a flickering one.

Naturally, the first thing you checked was that the electrical connectors were clean and securely fastened, no?

Sounds like an easy enough fix. Good luck!

Direct your motorcycle-related questions to, though some say we’re better at non-motorcycle-related ones…

  • DickRuble

    “What would cause the ABS light to intermittently come on then go off on an H-D Ultraglide?”

    Harley Davidson “engineering” causes that. They call it a feature. It’s included in the price.

  • ADB

    Davidsons have brakes? Who knew?

    • kenneth_moore

      Why yes, yes they do. But, only the rear brake is actually functional. The front brakes are purely decorative.

  • Starmag

    That light isn’t really for ABS. It’s secretly the “you haven’t spent enough money at the Harley shrine yet” light. You’ll notice it goes out as your wallet gets lighter. Someone has to pay for those motorcycle cathedrals. The “you pay for our advertising” lifestyle apparel sales can’t do it all.

  • Old MOron

    Okay, two things:

    1. Like all “Dear MOby” articles, this is an interesting and informative piece.

    2. Where is Sayyed Bashir? Will he not defend Harley’s honor?

    • DickRuble

      2. He’s stranded somewhere on a desert road, trying to figure out why the ABS light keeps blinking.

  • Mark Vizcarra

    The moron that did your wheels probably didnt properly install the sensor correctly. Wheel bearings rarely go bad, It’s the terrible service guys that did the work. Every more reason to buy the service manual and do it yourself

  • Vrooom

    It would seem that the bearings would have been inspected when the wheel was off? I’d go with the wire to the sensor too.