How do I know if my ABS module is dead?

Good Day,

Is there a way to tell if the iabs module in my 2003 GS is officially kaput? It's the server assist type, the one that Module Masters doesn't have a rebuild yet, (i think they've been a month away for 4 years).

My was getting a "low pressure in rear circuit error". I flushed/bled, didn't solved the problem. I switched out to new stainless brake lines, still didn't resolve it. Tried a couple of fixes I saw in other forums and now I have no rear brake pressure at all--probably my screw up.

I Finally relented and called the dealer to make a service appointment, but they are booked out for 2 weeks plus. I'm hoping there is a way I can at least find out where I stand sooner than that.

Also, if anyone knows a good place to find listing of local mechanics, that would help.

Thanks for taking the time to read this.

jonnyballgame34 said:

Good Day,

Is there a way to tell if the iabs module in my 2003 GS is officially kaput? It's the server assist type, the one that Module Masters doesn't have a rebuild yet, (i think they've been a month away for 4 years).

My was getting a "low pressure in rear circuit error". I flushed/bled, didn't solved the problem. I switched out to new stainless brake lines, still didn't resolve it. Tried a couple of fixes I saw in other forums and now I have no rear brake pressure at all--probably my screw up.

I Finally relented and called the dealer to make a service appointment, but they are booked out for 2 weeks plus. I'm hoping there is a way I can at least find out where I stand sooner than that.

Also, if anyone knows a good place to find listing of local mechanics, that would help.

Thanks for taking the time to read this.

Click to expand...

Welcome to the forum!

Where are you located? Not sure what the other fixes were that you tried. Without your location and more information on how and when this started and what fixes were attempted it's tough to guess what might be wrong and what might help. One thing for sure is that the dealer will likely recommend replacing the unit which is in the thousands of dollars.

I'm sure GSAddict will come to the courtesy phone shortly... he's having a very busy summer with servo brakes and bad brake lines this year!

You might want to contact Module Masters even though the web site still shows that module rebuild as being "Under Development". Someone here, in another thread, mentioned that their K1200(?) iABS module was in the process of being repaired by MM. (Edit: Found the reference:https://forums.bmwmoa.org/showthread.php?91016-02-K1200RS-Brake-Warning-Light&p=1139216&viewfull=1#post1139216)

Another option is a company in Germany, RH Electronics, which has been rebuilding these modules for some time. Possibly a little more expensive than the price MM was planning a few months ago, and I suppose the shipping cost/time would be greater.

lkraus said:

You might want to contact Module Masters even though the web site still shows that module rebuild as being "Under Development". Someone here, in another thread, mentioned that their K1200(?) iABS module was in the process of being repaired by MM. (Edit: Found the reference:https://forums.bmwmoa.org/showthread.php?91016-02-K1200RS-Brake-Warning-Light&p=1139216&viewfull=1#post1139216)

Another option is a company in Germany, RH Electronics, which has been rebuilding these modules for some time. Possibly a little more expensive than the price MM was planning a few months ago, and I suppose the shipping cost/time would be greater.

Click to expand...

Yep...They've started rebuilding. My rebuilt module is "in the mail" to my BMW shop to have it installed. Looking forward to getting the Brick back in next couple of weeks.

GSAddict also repaired a dead iABS module this past summer. This was done using some donor parts and a lot of sleuthing. Some of the components seem to be unobtanium which has been a big part of the problem for repair shops. I also hear Module Master is now repairing iABS units but I suspect that is only under certain circumstances.

I contacted Module Masters about a year ago and was told that they could probably repair mine when I told them what the symptoms were. I ended up buying a used one.

Thanks to all who've taken time to look and reply on this.

I'm in Connecticut-

Problem started with brake error and getting error about low pressure in rear circuit. I should add that if I reset it, initially I could ride anywhere from a couple to to 20 miles or so before it came back. Usually it would show until my first significant use of the back brake, but the it started coming almost immediately

-tried changing pad because I had a pair handy, and rebleeding

-switched from rubber hose in back to stainless. Frankly I'd been lax on maintenance so I really expected this to be the fix.

-I took out the plungers and inspected them per this link

https://forum.hexcode.co.za/forum/index.php?topic=4.0 I'm unsure if I made things worse doing this or it's just a timing coincidence, but it wasn't long afterward that I lost all pressure in rear brake. The pedal does nothing now.

I talked to Module Masters a month ago when this first started and they told me they were waiting on one part and hoped to have it within a month.....but when I talked to them yesterday they said the same thing, and looking through other forums it seems they have been saying "next month" for a long time.

Doesn't help that I'm not exactly a crack mechanic, most of the stuff I have to learn as I go along and I haven't had a lot of luck finding detailed documentation that dumbs it down for someone like me. I'm also trying to figure out if there is a way to fill/reset it with my GS911. The Clymer manual says that fills, etc. have to be done by BMW with the moditec, not sure if I need to believe that.

I do fully expect the dealer to tell me it's shot, but I don't want to wait two weeks to be told that because I'm going to have them fix it. I'll wait for Module Masters to be available, but if that's the case I'm going to need to think about adding another bike.

Again, any and all advice is appreciated. Thank you

Just realized I failed to ask a rather obvious question. If it is related to the module, is there anything the dealer can fix, or am I likely to just be told it needs to replaced no matter what the problem?

Module Masters rebuilds ABS modules. They show $250 for a BMW on their home page.

https://modulemaster.com/rebuilds/

EDIT: Sorry, I missed your earlier comment on Module Masters

jonnyballgame34 said:

Just realized I failed to ask a rather obvious question. If it is related to the module, is there anything the dealer can fix, or am I likely to just be told it needs to replaced no matter what the problem?

Click to expand...

As I said in Post #2 "One thing for sure is that the dealer will likely recommend replacing the unit which is in the thousands of dollars."

They don't do repairs on much these days. They do R & R. Remove and Replace. Current price at MaxBMW is $2795.29 plus labour and tax of course.

Johnny,

You mentioned you bled the brake, was that just the rear one? When was the entire system bled and fluid changed, has it been done on an annual basis. Can you advise how many miles are on the bike.

happy wanderer said:

As I said in Post #2 "One thing for sure is that the dealer will likely recommend replacing the unit which is in the thousands of dollars."

They don't do repairs on much these days. They do R & R. Remove and Replace. Current price at MaxBMW is $2795.29 plus labour and tax of course.

Click to expand...

Actually that is less than what I expected, especially given Module Masters already has set the price at $750 even though the rebuild is still under development.

jagarra said:

Johnny,

You mentioned you bled the brake, was that just the rear one? When was the entire system bled and fluid changed, has it been done on an annual basis. Can you advise how many miles are on the bike.

Click to expand...

Jagarra,

Thanks for looking at my question.

-It was front and back
-Changes have not been done on an annual basis---this bike has deserves way better than what I've given it in terms of maintenance. Right after the brake problem started my fuel pump died. These are the first two mechanical problems I've had in 15 years and almost 100k miles.
-It has 95k miles on it

Find someone that has a GS-911 scanner and get them to scan the bike for the ABS fault codes.
Post them here when you get them please.

GSAddict said:

Find someone that has a GS-911 scanner and get them to scan the bike for the ABS fault codes.
Post them here when you get them please.

Click to expand...

I can do that, thank you does attachment work and is this all you needed to see? Thanks again

jonnyballgame34 said:

I can do that, thank you does attachment work and is this all you needed to see? Thanks again

View attachment 70046View attachment 70047View attachment 70048

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Forgot to add rear brake test.. this is actually a little more pressure than I expected. The front came in low too, but I didn't take the time to shim the pads first so I expect that was the problem.

jonnyballgame34 said:

Forgot to add rear brake test.. this is actually a little more pressure than I expected. The front came in low too, but I didn't take the time to shim the pads first so I expect that was the problem.

Click to expand...

Thoroughly bleed the rear control circuit via the 3 bleed screws. Do the sequence twice at minimum.
Do the same on the front control circuit.
I prefer a power vacuum bleeder to do an effective job.

Then do the test with the calipers on the rotors. You need to be able to hold/maintain the pressure in the green for the specified time period for a pass.
It takes quite a push/squeeze to do that.

GSAddict said:

Thoroughly bleed the rear control circuit via the 3 bleed screws. Do the sequence twice at minimum.
Do the same on the front control circuit.
I prefer a power vacuum bleeder to do an effective job.

Then do the test with the calipers on the rotors. You need to be able to hold/maintain the pressure in the green for the specified time period for a pass.
It takes quite a push/squeeze to do that.

Click to expand...

Ok, was just out giving this another shot. Running into a problem---even with the vacuum bleeder, I can't get the fluid to come through the bleeders on the ABS until. I can get a little here and there but can't really get to where it is flowing steady, only drag out the occasional drop. And I can't really get any pressure from the pedal. ... THis is what had me assuming there was an issue with the module or I needed to find additional instructions.

Will try again first thing in a.m. Thanks again

jonnyballgame34 said:

Ok, was just out giving this another shot. Running into a problem---even with the vacuum bleeder, I can't get the fluid to come through the bleeders on the ABS until. I can get a little here and there but can't really get to where it is flowing steady, only drag out the occasional drop. And I can't really get any pressure from the pedal. ... THis is what had me assuming there was an issue with the module or I needed to find additional instructions.

Will try again first thing in a.m. Thanks again

Click to expand...

Make sure the rear master is at total rest and not partly activated otherwise you will not be able to pull the fluid thru
Remove the boot and confirm the piston is resting right against the circlip.

GSAddict said:

Make sure the rear master is at total rest and not partly activated otherwise you will not be able to pull the fluid thru
Remove the boot and confirm the piston is resting right against the circlip.

Click to expand...

to make sure I"m not doing something stupid, you mean like this? Maybe I just need to get a better bleeder vac because I can't get it to draw through-driving me nuts