When an ABS error light isn't an ABS system problem...

So, I noticed an intermittent ABS light for my trailer. No problem. Probably a loose wire or something.

I am on I80 for the next day and a half, passing by the Great Lakes, destination eastern PA, so I didnt want to ignore it.

I am very glad that I decided to stop and have it looked into.

Turns out that it was not just a loose wire. It was a loose HUB.

The tech plugged in the machine and read the fault. Right front wheel speed sensor error.

The lug nuts were tight, but when the tech jacked up the trailer to look at the sensor inside the right front hub, there was a problem.

The hub itself was loose. The entire right front dually tire assembly was wobbling a few degrees. Enough to see easily.

Apparently there is absolutely nothing wrong with the ABS system. The problem was that the speed sensor in the hub was intermittently losing track of the position of the hub as the tire rotated and wobbled.

The left side front axle also has some wobble. Little enough that it is hard to see, but it can still be easily felt.

An ABS error light might have just kept me from losing a hub at speed.

That's the last time I even consider ignoring an ABS light for 'just a short trip.'

 

Well, it's the next day, and the shop has been busy over night.

I asked them to check the other axle as well, if one axle had severe wear on the wheel bearings, the other might too. I was right to have them check.

Four wheel bearing assemblies and two slack adjusters for the trailer. I wonder if someone decided to hop a few curbs at speed with this trailer, or something?

In any case, they expect to be done in a couple hours, so I won't lose much time today.

 

Service was finished at around 10 AM. I drove a while, then stopped for a retorque on all four wheel assemblies.

No ABS light codes after the first 50 feet of movement.

All seems well. About 500 miles today with no detectable issues.