Check ABS!

[Devildog & Norma]

So, my new 2008 Workhorse chassis has a problem after 1900 miles, only 1100 miles which were driven by me. I traveled from Newport News, VA to Wilkesboro, NC without problem. It was performing flawlessly. Parked for five days enjoying the early fall days in the North Carolina foothills.

While moving the coach to the dump station my DW noticed a clinking sound coming for the left front wheel, she was outside the coach. Sounded like the wheel cover had a stone in it. I didn't think much about it, however, when I reached Concord, NC (Lowe's Motor Speedway) the sound seemed to have stopped

Leaving the campground after about two miles the ABS light came on. Oh, Oh, I think I have a problem. I'm determined to bring the coach home. I stop for gas after about seven miles. Restart and the light stays on, moved about 100 feet light goes out. Now the cruise control is not working. Houston, we do have a problem! About 325 miles later while coming to a stop the ABS light return, alarm sounds "Check ABS"�. Light now stays on the rest of the way home. Now I'm just waiting for my service appointment that will happen on Nov 10th. So, that my story of woe, thanks for listening.

Regards,

[Devildog & Norma]

So, my new 2008 Workhorse chassis has a problem after 1900 miles, only 1100 miles which were driven by me. I traveled from Newport News, VA to Wilkesboro, NC without problem. It was performing flawlessly. Parked for five days enjoying the early fall days in the North Carolina foothills.

While moving the coach to the dump station my DW noticed a clinking sound coming for the left front wheel, she was outside the coach. Sounded like the wheel cover had a stone in it. I didn't think much about it, however, when I reached Concord, NC (Lowe's Motor Speedway) the sound seemed to have stopped

Leaving the campground after about two miles the ABS light came on. Oh, Oh, I think I have a problem. I'm determined to bring the coach home. I stop for gas after about seven miles. Restart and the light stays on, moved about 100 feet light goes out. Now the cruise control is not working. Houston, we do have a problem! About 325 miles later while coming to a stop the ABS light return, alarm sounds "Check ABS"�. Light now stays on the rest of the way home. Now I'm just waiting for my service appointment that will happen on Nov 10th. So, that my story of woe, thanks for listening.

Regards,

[John-D]

Those symptoms sound strangely familure

Have someone stand behind your rig while you apply the brakes and report on the behavior of the lights.. I'm guessing your brake lights are stuck in the ON condition

Though burned out brake light bulbs will do it too

When it happened to me, under warranty, they replaced the brake light switch

Possible causes

Blown brake light fuse
Burned out brake light bulbs
Broken brake light wire
Bad brake light switch
Brake pedal not returning to full up
Riding brakes with left foot

[Duner]

Hey Devildog,
The sound you hear from the front wheel may not have anything to do with the ABS. Do you have stainless steel wheel covers? If so, they'll make some noises.

I would check the abs sensors at each wheel and make sure they are all seated completely in the cavity.

Just to be safe, I would jack up each wheel off the ground and make sure they all turn freely with no drag or signs of overheating.

Good luck,

[John-D]

The key is that the Cruise control no longer works

The only components that are common to both ABS and Cruise are

1: The Control computer (I think they both use the ECC) and 2: the brake light circuit

One of the ABS sensors is the brake light switch.It looks for the PRESENCE of 12 volts across the switch during POST (Power On Self Test) and then once it finishes post if it sees 12 volts on the switch OUTPUT it goes into "See if I need to act" mode.

Likewise the cruise control looks for 12 volts across the switch, zero volts means "Return to standby" or, "Drop out" depending on how you wish to name the mode.

So the fact that both ABS and Cruise are not working narrows it to the brake light circuit

Fuse, wire, switch wires and bulb

(Burned out bulbs means there is no "Ground" for that 12 volt reading it needs, NOTE that 12 volts is "Battery voltage" or "System voltage" and not, precisly 12 volts)

So blown fuse, no 12 volts to the switch
Burned out bulb, no ground to the switch
Broken wire, same as BOB
Bad switch 12 volts both sides ("ground" is now 12 volts)
Riding the pedal with left foot same as switch

And that about covers the things that can cause it

I can tell you how to demonstrate this

Step on the brake, start the engine, you will see the same symptoms (This is an easy way to temp disable ABS by the way) To fix, shut down and restart engine without touching the brake pedal.

[03HRVacationer]

John D,

Great Reply, it's posts like this that keep me reading this board the way I do and keeps my wife wondering what I'm doing.

Excellent info.

Al

[dieselclacker]

Devildog, check and see that the brake light switch has not slipped out of adjustment, and is riding against the brake pedal all the time. If it has, it will cause your problem as explained by John-D above.

Dieselclacker

[John-D]

Thanks O3HRV. Of course if I'd not "Been there and done that" I'd not have been able to make that post.

I sometimes tell of how the service center told me it once took over 2 weeks to get parts from Workhorse... So I called Alan, got the part, taped it to his business card, and when the appointment came handed them the card.

Took 'em something like 2 days to get that switch and there were only a handful of them scattered around the US so one day was finding it.

Amazing what the right business card does

[Devildog & Norma]

Thanks for all the replies. John-D, I'll head over the the MH in the am and see what I find. I did check all the fuses and all seemed okay. Now onto the brake light switch. Thanks again.

Regards,

[Devildog & Norma]

John-D you were right on the money. So, I return with my head hung low and admit I did not check that 20A fuse marked "BRAKE". I thought the brake circuit was on the 10A fuses (all check good). It appears all is good now except for the clanging noise coming from the left front wheel. Thanks again!