ABS problem

[Boss68]

I have a 2005 workhorse chassis and as soon as I turn the key on the abs light comes on and when I start check abs comes up on the screen. I pull all 4 sensors cleaned then all read 2200 ohms it has a W0000254 controller. Who makes the controller and is ther a wiring diagram for it so I can check the wires at the controller ?

[MrMark52]

Look on the Master Cylinder - there are 2 sensors, one in the tank, the other in the Master Cylinder.

Unplug the one in the Master Cylinder. If the light goes off, you found the problem.

Horrible design as a means to warn the driver of a differential pressure between the front and rear brake systems (meaning, you got a leak). So far as I’ve found, not repairable - I’ve yet to find a kit for one. New MC is about $300.00.
Only prevention is routine maintenance (bleeding) the brakes every 2-3 years - brake fluid absorbs moisture which crud’s up the system, including the actuation rod that is under that switch.

I’ve been driving ours with the plug unplugged for nearly 2 years now. I might fix it, someday.
But I will do a routine bleed of the brake system.

[Boss68]

I unplugged sensor replaced fluid and bleed everything and still have the same issue

[MrMark52]

Well, recheck your sensors - after that, you’ll have to find a heavy truck shop that used to work on Workhorse, many of them are now also Navistar shops. It takes a special reader to see the codes in the ABS for the Workhorse.

The shop that did the recall brake work on ours, I had him replace the pads all around and do a lube job and check the reason for the ABS.
He was a good old boy at a Navistar/exWorkhorse truck shop - his report came back, bad sensor on driver front, and that plug I told you about.
I drove the coach for a year with the ABS light on and that sensor unplugged - you have brakes, but not ABS. Finally got around to replacing the sensor - 10 minute job - was barely out of the driveway when the ABS light went off, and (knock on wood) has not been back on since (other than when turning key on to start the engine).

Shop around for sensors - you can find a wide range of prices for the same part. Don’t recall where I got mine.

[Ray,IN]

Quite often the tone ring slots become dirty enough to trigger the ABS light. When we bought this MH the ABS light was on all the time.
My auto mechanic told me to pressure-wash the backside of each wheel from the opposite side of the coach to try and clean out the tone ring slots.
I did, and it worked. Ever since then the ABS light comes on with ignition key, and after the diagnostic checks are complete the ABS light goes out.


If you can't tell , I subscribe to the KISS principle.