ABS Light Staying ON......

[Capt Joe]

After my brake problem of last week and getting the drivers side caliper replaced under the Workhorse 'warranty' they are extending for repairs while waiting for the final recall to start, we took off the end of the week to spend the Memorial Day weekend at a COE park up north of Eufaula, AL.

No problems with my brakes at all during the trip...including a couple of real hard stops thanks to some stale traffic lights changing and catching me. BUT, on the return trip...about 180 miles, I see the ABS light burning on the dash.....brakes still working fine so I figure it is just something with the anti-lock system and I've sure driven many a mile without ABS in other vehicles so I wasn't too worried. We stopped for a bite of lunch and the light stayed on after cranking up to leave the lunch stop. Stopped just about 5 minutes later for fuel and then after leaving the fuel stop, the light went out after about 5 minutes on the road. Thought all would be well but it came back on about 10 or 15 minutes later.

I've seen the page on Omny's web site about cleaning and reseating the sensors....Does anybody think that will possible clear the light problem? Might not be a bad idea to do it anyway.....Any other instructions available....pictures?....for doing the R&R on the sensors, cleaning, replacing, etc.

Thanks for any and all info....

Now to get rid of the ants we picked up over the weekend.....Ideas on that will sure help too.

[ichn2go]

Capt. Joe, there's no better instructions than on Oemy's wesite. You can call OEM Engineering and talk to Glenn. He will tell you how to OHM the sensors. They do not have to be removed from the wheel just disconnected. Use a straigtened paperclip to stick in one side of the connector and a probe in the otherside. They should read something over 1100 ohms if I remember correctly. This is a very simple way to find the bad sensor. OEM Engineering has the sensors and Glenn is very caring and will give you the exact reading for the ohms and walk you through the process.. I have been through this several times for one reason or another. If your wheels got real hot . then it can ruin the ABS sensor. Good luck and don't be afraid to call Dale(Oemy) or Glenn they are fine folks. BE SAFE

[dveasey]

Capt. Joe...
In order to simply "clean" the sensor head...it's a simple pull-it-out, wipe-it-off and press it back in all the way.
You can crawl under the vehicle and see the wire going to the sensor & the sleeve into which it goes. Located near the top quadtant of the rotor housing. Fully accessible without tire removal.

The wire does not need removal; leave it connected.

The sensor is shiny aluminum cylinder that inserts into a copper sleeve on the brake housing. If it resists your pulling pressure you can use a screwdriver to lever it out. Don't use the prying to remove it altogether; but rather to simply "get it started". You want to pull it outward by hand alone (straight and ninety degrees to the sleeve)...(Levering would pull it toward one side or the other.)

If the copper sleeve begins to creep "out" when you withdraw the aluminum "head"...just "stop" the process & push the sleeve back into place with the tip of the screwdriver; and then continue to remove the sensor head (with wire attached).

Once you have it "out"..just wipe it clean with a clean shop rag or towel. Should see plenty of brake dust residue on the tip. Before reinsertion, check the wire integrity for good fit, no breaks. Then, lube the shiny head with a small film of PTFE lube or moly. Just a tiny film coat; wipe away excess.

Press the part back into place...seated all-the-way....and you are done.
Do all wheels at the same time & log this down as an annual DIY-er job <or> at least your 2-year brake fluid renewal interval.

Piece-o-cake. Your first crank-up might lite the ABS light on dash, but it will go "out" & all is well. If you did not press one all-the-way home into the sleeve..you might have to recheck.

Hope this helps.

[Capt Joe]

dveasey,
Thanks a lot for the added info on cleaning the sensors. I just got out from under the MH and as you said...Piece-O-Cake. I used a bit of electrical contact cleaner on a rag to wipe off the sensor and lubed it a bit with some white lithium then seated them fully...until they felt as they hit a solid stop.... Cranked up and the ABS light stayed on. Idled for about 5 minutes without it doing anything but blink at me two times...didn't stay off at all, just a momentary blink.

Guess I need to check the OHM reading on the sensors.

Question, please.... Where does the wire actually plug in on the sensor. Is it the larger black rubber part (about the same diameter as the sensor) or is it at the end of the wire where it goes into the black rubber part?

Or....do I need to put it on the road for a little bit to let the ABS system do its self check while moving? I know the manual says it does a self test and you may hear some clicking after start-up while it it testing itself. I was unable to move it more that about a foot right now without backing around a huge camillia bush here at home. Maybe someone can verify if I need to drive it to get the testing done and the indicator light to show me all is working as it should.

Thanks,

[ichn2go]

Capt joe, the sensor plugs into the wheel. The wire coming from the sensor plugs into a connector. Remove the wire from the connector and ohm the wire going to the sensor..Yes ,,you must move the coach about 1/4 to 1/2 a mile for the ABS system to reset itself. drive at low speeds. GIve Glenn a call at OEM Engineering a call and he will tell you all about what you need to know..Sensors are about 70.00 plus shipping. Good Luck

[billyb]

you might have to disconnect the negative battery cable for about 15 minutes and then after reconnecting it, drive several miles

[Capt Joe]

Thanks Guys.....
Just got off the phone with Glenn...He sure is a nice guy over the phone. He confirmed that I do need to drive at least 1/4 mile to have the ABS reset itself and you do have to go over 5mph. He was also very helpful in checking the sensors by testing the OHMs so if the light stays on after my drive in the am...and disconnecting the neg batt cable if the drive by itself doesn't clear it, I'll be on the phone back to Glenn to order any new sensors I may need.

Thanks again...Nice to have such an informed band of brothers to help each other out with these type of thing. I did e-mail the Workhorse folks and their reply was that I needed my 'system code checked'...which would, I'm sure even thought that is probably the correct corporate answer, wind up costing a pretty penny for something I should be able to do without having to go through the hassle of going to the Service Center.

Thanks again. I'll post later with the final outcome.

[ichn2go]

Capt. Joe,, I never disconnected any battery.. I just ohmed the ASB sensors till I found the bad one...You may as well order 1 new sensor from Oem Engineering ,,but for your peace of mind give Glenn a call and Ohm your Abs Sensors...Good luck

[ichn2go]

Capt Joe, we are fortunate to have Glenn around ,, I have spoke to him many times and he is truly a fine fellow. He even called me to ask if I found the problem ...you were wise to give him a call and yes its cheaper to ohm than have the Abs system read. First of all you have to find a place with a Tech2 that has a GM ABS system installed in it. I had to go to a ex Workhorse Dealer ..There was nothing wrong with the Abs System and it only cost 101.20.. OHM Capt Joe OHM..

[oemtech]

OBTW - I don't think a Tech 2 will read the Menitor Wabco ABS System.

[DriVer]

Quote:

Originally Posted by oemtech OBTW - I don't think a Tech 2 will read the Menitor Wabco ABS System.

Dale, Where'd this info come from?

[oemtech]

Quote:

Originally Posted by DriVer Dale, Where'd this info come from?

I got from the Meritor Wabco Maintenance Manual No. 39.



Section 2 Page 10.

Quote:

** NOTE: The Tech 2 cannot access the Meritor Wabco® ABS module. Diagnosis can be accomplished using the Toolbox® software connected to a PC using the appropriate adapters and cables. Diagnostic “blink codes” can be retrieved using the procedure described on the following pages of this section. Workhorse chassis are not equipped with a Blink Code switch. To access the fault codes perform the following steps: • Locate Pin 8 of the Black X-2 Connector at the ABS ECU • Backprobe the circuit at the connector with a jumper wire • Ground the other end of the jumper wire for 1 second and them remove • The ABS should begin to flash the stored code(s) in memory

[Capt Joe]

Dale,
Anything in that manual on a blink codes without having to jumper anything. As noted above, after cleaning my sensors today, whenever I started the MH, my ABS light would, after about 5 seconds, blink once then a few seconds later blink again....then remain steady on. Should this tell me anything? If needed, I'll actually time it in the am. I'm going to take her for a ride to see if the ABS self diagnostice will reset it after the cleaning. Glenn told me it needs at least a 1/4 mile ride and have to go over 5mph to get it to reset.

Thanks,

[oemtech]

My ABS stayed on after I cleaned and reset the sensors... It went out after I drove about 1/2 mile.

The manual goes into great detail about the blink codes.