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New purchase, iabs failure fun

T

tpmcleod24

New member
Hello, wish i was here to celebrate the purchase of a really nice low mileage 2004 1150rt. However, I am here to sadly say i recently purchased a really nice low mileage rt with iabs failure. Test drive was fine, but after a longer drive home from the purchase, the failure light came on with the 4hz flash and general light on. If the bike sits, i can get the lights to clear and even had it clear and work fine on the way to the mechanic. I had a local independent bmw mechanic do a full flush on the system and had very dirty fluid. After the work, everything worked good until about 30 mins down the road on the way home. The lights come on, the front still has servo assisted braking, but no rear servo assist. Eventually both go into residual mode. The code thrown states high pressure in the rear circuit. It has the original rubber hoses.

I understand there may be an opportunity to have a rebuild by module masters, but am concerned about future failures. I am considering removing the iABS unit, but have not been able to find a comprehensive procedures with clarity on having to re-wire or not re-wire for brake lights.

Any information on iabs removal for a 2004 rt would be much appreciated.

Thanks,
Travis
 
You may have answered a question already, change out those rubber lines...then do another flush including voiding calipers

Some folks have removed the pump, imagine a youtube or regular search will lead tou down that path...but,doyou really want to?
 
No, really do not want to, but do not want to keep putting money into it only to find out it was the abs module. Would the brake lines still cause a problem that fast after the two flushed performed by the mechanic?
 
If the lines break down internally like they all eventually do, little rubber bits can clog orifices and keep fluid from flowing either direction.
If the module fails , typically done from the get go, blocked lines just make things worse.
 
tpmcleod24 said:
Hello, wish i was here to celebrate the purchase of a really nice low mileage 2004 1150rt. However, I am here to sadly say i recently purchased a really nice low mileage rt with iabs failure. Test drive was fine, but after a longer drive home from the purchase, the failure light came on with the 4hz flash and general light on. If the bike sits, i can get the lights to clear and even had it clear and work fine on the way to the mechanic. I had a local independent bmw mechanic do a full flush on the system and had very dirty fluid. After the work, everything worked good until about 30 mins down the road on the way home. The lights come on, the front still has servo assisted braking, but no rear servo assist. Eventually both go into residual mode. The code thrown states high pressure in the rear circuit. It has the original rubber hoses.

I understand there may be an opportunity to have a rebuild by module masters, but am concerned about future failures. I am considering removing the iABS unit, but have not been able to find a comprehensive procedures with clarity on having to re-wire or not re-wire for brake lights.

Any information on iabs removal for a 2004 rt would be much appreciated.

Thanks,
Travis
Click to expand...

The rebuild by Module Masters comes with a warranty, I believe 5 years. But you still have to have someone do the work of removing and reinstalling. I had a '02 K bike ABS module rebuilt by MM and work done at a dealer. Depending on who does the work, you may be looking at $1-$2k bill. Contact MM and see what they'll charge for your rebuild and turnaround time. :dunno
 
If you're able to bleed the brakes you shouldn't have any trouble replacing the servo unit. There are no special tools needed except the funnel used for putting the the fluid in the under tank reservoir.
 
Change out the lines to SS teflon. That has to be done no matter what.
Then fill/flush thoroughly.
If you can't get the modulator to function correctly after that, then have it rebuilt or bypass it.
 
Module Masters is not currently re-building iABS. Please double check with them prior to removal, if that is the path you choose.
 
henzilla said:
I thought that as a factor, but the high pressure code took me to blockage somewhere
Click to expand...

The simple things. The ECU on our bikes aren't AI yet. They are actually very dumb.

I had the exact same issue on a k-bike this past summer. Chased ghosts for weeks. Turned out to be the alternator. Yep.

Just fixed my buddie's 2005 F-150 with "low compression on #5, need to do the heads" and "we need to replace the EGR valve because of low flow" and "your rear abs sensor that we just replaced didn't help because we need to rebuild the rear end" with a new battery.

Always start simple and then start again at simple.
 
Again, thanks for the replies. I have the parts and tools coming in this weekend, will hopefully be able to do the brake line replacement and flush. I should be able to clean and check clearances on the sensors as well. We will see were that lands us.

I have tested the battery at off, startup and idle and all appears well from a battery and charging perspective. The mechanic confirmed the same.

This bike does have an aftermarket led modulated brake light. My experience with LEDs is that they draw less power than standard bulbs. I assume it could be possible that the draw on this is fluctuating and being detected as a failure. I would not expect that to result in a pressure to high, but weirder things happen.

I have been suspecting a possible rear brake switch, and attempted to test that for open/close, but not sure if I am testing right. I removed the connector and put a lead on the female "hole" under the pin. I then ran a continuity check between the female hole and the pin above it and it stays closed/shorted, regardless of switch position. The same happens on both sides, as there are two pins and two female "holes" underneath them. I assume I should see an open when i depress the brake pedal and "open" the switch. The rear lights do come on as expected, so I assume I must be testing wrong. Any thoughts on testing the rear brake switch?

As far as the module rebuild goes, i have submitted a request into module masters and will be monitoring that to see when they may be able to perform a rebuild. I read on one of the other forums that it may be as early as this month that they could start working the pipeline of requests.

I'll update following any progress.

Thanks to all,
-Travis
 
tpmcleod24 said:
Again, thanks for the replies. I have the parts and tools coming in this weekend, will hopefully be able to do the brake line replacement and flush. I should be able to clean and check clearances on the sensors as well. We will see were that lands us.

I have tested the battery at off, startup and idle and all appears well from a battery and charging perspective. The mechanic confirmed the same.

This bike does have an aftermarket led modulated brake light. My experience with LEDs is that they draw less power than standard bulbs. I assume it could be possible that the draw on this is fluctuating and being detected as a failure. I would not expect that to result in a pressure to high, but weirder things happen.

I have been suspecting a possible rear brake switch, and attempted to test that for open/close, but not sure if I am testing right. I removed the connector and put a lead on the female "hole" under the pin. I then ran a continuity check between the female hole and the pin above it and it stays closed/shorted, regardless of switch position. The same happens on both sides, as there are two pins and two female "holes" underneath them. I assume I should see an open when i depress the brake pedal and "open" the switch. The rear lights do come on as expected, so I assume I must be testing wrong. Any thoughts on testing the rear brake switch?

As far as the module rebuild goes, i have submitted a request into module masters and will be monitoring that to see when they may be able to perform a rebuild. I read on one of the other forums that it may be as early as this month that they could start working the pipeline of requests.

I'll update following any progress.

Thanks to all,
-Travis
Click to expand...

Just to reiterate from a previous post, I had a 2000 RT with ABS warning lights and original rubber brake lines. Upgraded the lines to stainless, purged and flushed the system and the problem went away. As you plan to replace the lines anyway, at least give it a try before you tear everything apart....?
 
flhfxd said:
Just to reiterate from a previous post, I had a 2000 RT with ABS warning lights and original rubber brake lines. Upgraded the lines to stainless, purged and flushed the system and the problem went away. As you plan to replace the lines anyway, at least give it a try before you tear everything apart....?
Click to expand...

Agreed, that is the plan. I plan to replace lines and flush and see how things work out. I would not be looking to remove the module until i have attempted the lines, flush and sensor validation.
 
Don’t forget to include a careful look at brake lever/hand lever operation and the microswitches associated with them, as a malfunction there can also trigger an ABS fault.

Best,
DG
 
Quick update....brake lines replaced, fluids replaced and bled. So far, all is clear, will be test driving this evening.

I did have a rookie mistake with with one of the fluid level sensors on the module. I was cleaning up some minor spillage that had gotten into the connectors when removing the funnel. I bent one of the pins in the front circuit fluid level sensor connector and it ultimately broke off when trying to straighten it out. I was able to insert a piece of wire into the connector and after a few tries was able to get it to make contact with the "stub" on the male side. So far, no codes being thrown. If codes get thrown from the sensor, i will need to figure out a more permanent solution (hopefully not having to replace the module)...

Fingers crossed, drive test tonight weather permitting..

-tp
 
I now own a really nice low mileage 2004 rt with a functioning brake system. Went for a 35 mile ride and experienced no issues or lights. Every ride before had a the issue occur within 15 to 20 miles of riding. So far so good.

Thanks to all for the suggestions and support.

For reference, I drained brakes, replaced lines with speigler kit, filled and then bled. The initial drain still showed some dirty fluid, either left from the previous flush or due to the brake lines braking down very badly.

WARNING: Be very careful with the fluid level sensor connectors on the abs unit, the two pins do not favor morons.
 
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