Accessing Meritor ABS Diagnostic Codes

[wolfe10]

Have had an intermittent ABS light illuminate while driving. Sometimes more than a thousand miles between occurrences.

Removing the passenger's front kick panel, I see the ABS diagnostic port and a toggle switch below it.

Would like information on reading the codes using the blink codes on the ABS dash light.

Specifically, what are the steps to check for codes: Ignition key on/off? Toggle switch below ABS diagnostic plug on/off or other. The Meritor troubleshooting manual mentions a momentary switch which I did not find. It could be that Alpine installed the toggle switch instead of a momentary switch.

Thanks for the assistance.

Brett
2003 Alpine
Hydraulic over hydraulic brakes
Meritor Wabco ABS

[Old Scout]

Brett--you are exactly at the point in your research that I was a few years ago. Couldn't find the "momentary switch" to induce the flash codes. My ABS light has been going on and off for years--one day it is on all day, then the next day it is off and might stay off for several days. Interestingly, if/when I stop for fuel and let the engine run [which is my practice], more often than not the ABS light will be on when I return from fueling. I have cleaned and re=positioned the wheel sensors, check reservoir fluid levels, etc but have never found a root cause. Despite the light being on, brakes and ABS appear to continue operating normally......Accordingly, I tend to live with it.....

[SteveS]

Exactly the same situation with me as with Old Scout.

[tiredvet]

Same here,drives me nuts.It's enough to make you want to pull that bulb.

[wolfe10]

So, has anyone taken their coach in to a service center (truck shop) to have the ABS diagnostic plug accessed to check for codes? Results?

[wa8yxm]

Merritor ABS is a lost cause.

[Old Scout]

My recollection on the forum is that finding someone who knows about Meritor ABS is nearly impossible. The best shot seemed to be shops that build/work on school buses as this system is/was often used on that type of vehicle.
Somewhere along the way I read that you can induce the flash codes by shorting one of the monitoring plug leads to ground. All I managed to do was blow the 12v fuse somewhere [which I cant find]. How do I know this?????--I found I didnt have independent 12v power to my engine plug when I tried to install my SilverLeaf SPpc cable/serial adaptor [OOOPS].....

[sfi4]

Good Evening;

Here's the Meritor / Wabco Manual if you need it

It shows in the diagrams the connection for the Blink Code Switch

Also has the codes / troubleshooting instructions

Hope it helps

[tiredvet]

Originally Posted by sfi4

Good Evening;

Here's the Meritor / Wabco Manual if you need it

It shows in the diagrams the connection for the Blink Code Switch

Also has the codes / troubleshooting instructions

Hope it helps

Many thanks.Guess what I'll be doing on our up coming trip.

[wolfe10]

sfi4,

Thanks for the link. Yes, I had already downloaded the Meritor/Wabco manual. But, was on the coach today with it and could not determine how to access the blink codes. Again, no momentary switch as mentioned in the manual. That is the reason for the original post.

[tiredvet]

Originally Posted by tiredvet

Many thanks.Guess what I'll be doing on our up coming trip.

Well darn it anyway.Maybe EM can solve the issue?

[Old Scout]

Yup--should have mentioned that I too have downloaded the manuals--no joy!

[Beagle RC Air]

I have a Wabco/Meritor toolbox cd. It worked to bleed the modulator on the abs. Anyone need one they can have it for what I paid for it.$49.95. I think it is bootleg copy but it worked.

beagle

[wolfe10]

Beagle,

Please explain "bleeding the modulator" and how a CD accomplishes this.

Was your ABS light on (all the time, intermittently, not at all) prior to this-- after this as well?

How do you use the CD/how do you connect the ABS diagnostic port to your computer (at least I assume this is to your personal computer).

Thanks for the tutorial!

Brett
2003 Alpine 38'