ABS Light illuminating

[Corkman]

I have 2001 Monaco Dynasty, ISL CM554 8.9L and the ABS light just today started illuminating while driving.

I've seem some threads indicating that the owners can use the ABS module/box to troubleshoot ABS issues (buttons and/or light).

Anyone know where the ABS module is on my coach, and/or have the ABS troubleshooting guide?

 

Thanks in advance,

Bill

[Jerry G]

I had similar in my 01 Dynasty.

Cummins and one other place said they could find nothing and brakes were OK

 

Decided to put black electrical tape over idiot light.

Stayed on for a couple years.

Got cut off and had to hit brakes hard(I use exhaust brake to slow mostly).

What do you know. Light went out and hasn't come on in another couple years for whatever it's worth.

[Russ R]

Mine came on. Took it to my mechanic who told me there was nothing wrong with the ABS. He said that there was no codes showing or stored. It is a circuit board that feeds the ABS light on the dashboard. The only thing it does is trigger the light. The circuit board is obsolete. So a replacement is not available. See attached picture of the board. I took the bad board to a local electronics company that repairs circuit boards. They told me that the "test button" was bad. They replaced the button and that took care of my problem. No more ABS light.

 

Edited December 6, 2022 by Russ R

[Ivan K]

Depends which make ABS you got. My 2000/2001 manual shows test button right beside the 6 pin engine connector by my left knee, under dash and that's exactly where it is. No circuit boards, just wiring to ABS controller in ceiling of a baggage compartment. Found it there whire chasing a broken retard wire. Blink codes worked for me perfectly.

[Corkman]

Where is that board, in your picture, located Russ?

Ivan, where are you getting the information about the blink codes?

[Russ R]

Outside Electrical bay under the driver. 

[jacwjames]

My ABS diagnostic module is also located in the front drivers side electrical bay.   Check your manual as mine has a detailed section on the ABS system including where the button or board is and how to retrieve codes.  If you do find the module and get a fault code report back. 

Russ R is correct, the board is obsolete but might be repairable.  https://www.nwrvsupply.com/product/info-only-no-longer-available-repair-info-only-16614041-kib-abs-repair-info-below/

Over the years I've had the ABS light come on and have used the diagnostic board to provide the fault codes.  It is a blink two part code.  If there is a fault it will provide the reason and if it is wheel specific.  ~6 years ago I had one that indicated that the sensor on the front drivers side wheel was out of tolerance.  Pulled the sensor, cleaned it, put it back in and that solved the problem.

I have also had the button on the diagnostic board stick.  The first time I took the board out of the bay by unplugging the harnesses and removing the 4 mounting screws.  I then took compressed air an blew the button out and got it working. 

This happen again last year except the button didn't seem to be springing back they way it should.  So I took the board back out and took the button apart.  Under the button there is a very small metal plate with 4 spring legs.  I carefully bent each leg a little and put it back together and it worked, the button would click as I was pressing it.  I think the reason the fault light was coming on was that the spring plate was not releasing from the contacts. 

One last word of advice is to understand how to check the codes.  I found out the hard way not to hold the button down for more then 2 seconds.  I held mine down too long and it put the system into Dyno mode which disables the ABS system.  The manuals said that when the coach is driven it should revert back to normal but mine did not.  When I checked for fault codes it showed Dyno Mode.  It took me long time to figure out how to get it out of this, normally a tech would use a computer which I did not.  I finally found a procedure to get it out of Dyno mode, took 2 people, one in the cab pushing the brake pedal and holding it down in a specific sequence while the other pressed the test button.  Finally got it out of Dyno mode and now release the button after a count of 1!!

 

[Ivan K]

1 hour ago, Corkman said:

Ivan, where are you getting the information about the blink codes?

Bill, it would depend on the system, the codes are somewhat different between them. There are documents in our downloads (chassis-brakes). Mine is by  Eaton and no circuit board in FRB. Just a momentary push on the button under steering wheel starts the blink sequence. 

Edited December 6, 2022 by Ivan K
Correction

[jacwjames]

I checked the 2001 Dynasty manual, the test button is under the dash similar to Ivan's.  Look at page 252 for info on the ABS system and how to check codes.

[Corkman]

Ivan K and jacwjmes, thanks for the help. I found the button for my Eaton (per manual it's an Eaton), and got the following codes:

10 -1

10-2

10-6

Now how do I find out what that means.

Edited December 6, 2022 by Corkman

[jacwjames]

It should have been a 2 part flash, here is a document that explains the system, the fault codes are listed starting on page 21

Make sure you follow the instructions, not sure on yours but on mine I have to turn on the key (no start), wait until dash lights go out, press the brake pedal one time, then press the button. 

ABS Brake Bendix Service Data.pdf

Edit>> checked the codes you listed, all have to do with a short circuit.  Need to confirm which system you have and make sure you have the right document to trouble shoot.

Edited December 6, 2022 by jacwjames

[Corkman]

Jacwjames. I updated my post, see above. If my manual says it is an Easton ABS system, that means mine is diff than your Bendix sys, correct, or is Bendix a subsystem of the Eaton system?

[jacwjames]

Eaton and Bendix merged in 2002

See if you can find the specific info on your ABS system and search for a manual

Chances are the one I attached is dated 2006 so it may work.

[jacwjames]

Here is the parts page for my ABS controller, not sure if yours will be the same as at some point Monaco added the ATC, which I have. 

You might be able confirm you system by finding this.  Mine is located in my smallest basement bay where the inverter is mounted.  It is mounted on the ceiling, this bay does not have the covering over the ceiling. 

Hopefully someone with a Dynasty will chime in. 

 

1 ABS Module.pdf

[Ivan K]

I agree with Jim, 10- codes are for PMV (pressure modulator valve) on left rear axle. I would check the connector and cable visually first and then there are ohm values to check on the valve. I could not open Jim's document but if it's the same as I use, you already know. I also have Eaton ECU and Bendix manual works for it.

Alternatively,  if you find the ECU, you could confirm the readings by unplugging the related connector and measuring without getting under the rig.

Edited December 6, 2022 by Ivan K

[jacwjames]

Ivan,

where is your module located!!

[Ivan K]

20 minutes ago, jacwjames said:

Ivan,

where is your module located!!

Mine is in ceiling of the last, pullthrough storage bay, in front of AH compartment. A bit towards passenger side between rails. I have a huge ceiling panel there and it was fun when I had to tone out a broken wire.