2004 R1100S ABS fault codes

[rangeron]

I have a 2004 R1100S with 90k on it. Dutifully maintained. The ABS dash light came on and stays on, same with brake failure light. Did a GS-911 on the bike and shows: #17438 Pressure in rear wheel circuit too high and another of #17914 Faulty power supply to warning lamp relay. Any ideas? Take off ABS unit to rebuild?

 

[20774]

I found those fault codes in some older threads; see if they provide any insight or possibilities for a fix:

https://forums.bmwmoa.org/showthread.php?83877-ABS-III-fault

https://forums.bmwmoa.org/showthread.php?49729-ABSi-problem-on-R1150GS-2004-model

 

[jrogers]

Mine has done the same I cleared the codes and rode it and they came back on a couple days later. Cleared them again and they haven't ever come back on.
I did notice a few drops of fluid came out the overflow hose.

 

[rangeron]

The forum post from 12/10 shows the exact same 2 fault codes. Been cleaning the relays! Where is the warning lamp relay?

 

[pauls1150]

I don't know "how close" these are for an S model, but here's a picture for the fusebox under the seat for the twin-spark RT:


and one for the older 1100RT:

 

[rangeron]

I have ordered a new ABS warning lamp relay. Charging up a new BMW battery, but I don't think that's the problem. I have the rear brake pads off awaiting replacement pads all around. I may bleed the rear brake to see if that changes the high pressure reading. Then I will attempt to reset codes.
A friend removed his module on older K bike and sent it to Moscow ID for rebuild. Fixed the problem and he recently sold the bike. Hoping I don't need to do that.

So, stand by. If anyone has any other ideas, I'm open to suggestions!

 

[pauls1150]

Do you still have the factory brake hoses? The lining degrades over time, leading to a lack of flow and/or little bits clogging not just the line, but the tiny "return bleed" hole in the master cylinder.
This is why so many of us are happy customers of the Spiegler replacements.
https://spieglerusa.com/catalog/category/view/id/36
Aside from price, there are NO downsides to using these lines.

 

[rangeron]

Good tip. I had Speigler lines put on awhile back because I heard the old stock ones crapped out over time. Thanks tho!

 

[rangeron]

Since last post

As I mentioned, replaced all the brake pads. Replaced the ABS warning lamp relay. That fault then cleared. I replaced the battery with BMW gel. After that the rear caliper was binding as to the point of hard to roll bike backwards,etc. The GS911 still showed high pressure in rear wheel circuit, as in 1000 PSI in it and 250-290 in the other circuits. With the replacement caliper I attempted to bleed rear brake. There is no servo sound on the rear brake. I believe it's been out awhile. I bled the brake and that lowered the pressure to 800 PSI. All the fluids are clean, all the previous ABS warning lights still the same after clearing the faults.
Without the Servo sound, is the module crapped out and thus requiring removal and shippping to Module Master?

That's my current tale of woe. Thanks for any help?