ABS Failure

[bblalock]

Ok, I've "Searched" and read almost everything concerning this but no luck with a fix, yet. 52,500 miles. 3 days ago I almost couldn't bring her to a stop, and the failure light was blinking. Happened 3 times that day. It appears that after a number of braking cycles it starts to cycle pump on-off-on-off. The 'failure ' light will blink fast and the '!' will be on. When the brake is released the '!' goes off but the 'failure' continues but at the 1 per second pace. It also likes to fail if I manually back up.
The fluid did not appear low but I have since added to and then over-filled the rear and the two ABS reservoirs('05). No luck. I have removed and cleaned the front and rear sensors. No luck. I hope to have the fault codes read tomorrow.
Is there anything else I can try that might clear a simple problem if it isn't the ABS gone bad? I read somewhere about a reset of the ABS.

[jrlakin]

Is your battery good??? Have you had the brake system flushed recently?

[bblalock]

I ride every day, almost, so it always seems to be in good shape. Never a starting issue.
I'll check my records but I think the dealer serviced it when replacing the main seal at 36,000 back in May.

[jzeiler]

Well there is no "reset" for this system. It will clear itself if the cause of the original fault is repaired. The GS-911 unit will read the fault codes and help pinpoint the issue causing the fault. The only reservoirs that are monitored are the two on the ABS unit.


Are you still running the original battery? It sounds like after several brake application you get the fault and that is indicative of a weak battery.

[bblalock]

John,
I did turn the key on and pulled the brake lever and the lights continued but the ABS did sound odd after a bit. Puked some fluid since I filled'er up. I would have thought a weak battery would show itself doing that.
My wrench said there is a possibly the faults might show a light switch situation. That would be a good thing, if I am so lucky.
As I might have mentioned I'll try to check the faults tomorrow, Saturday or Tuesday at the dealer.

[jzeiler]

Benton,


A better check would be to start the bike and drive until the roll out test completes (all warning lights off). Then sit and pull hard several times (at least 4) on the brakes to see if a fault shows up. Even with the engine at idle this will show a low voltage fault if the battery is weak. If that does not cause it to show a fault your battery is most likely NOT the culprit. Best to get a readout of the codes as they do remain in memory even after the warning lights go out.

[bblalock]

John,
The faults are to read later today.
The battery took a full charge, per the BMW tender. Seemed to be longer before the first fault.
I'll post the verdict when it is known.

[cfell]

Benton... when in doubt, "whup it out"...

Better to spend $100 on a new batt than $1k on new ABS.

Also, it is amazing what a "flush" can do to improve "performance"...

[bblalock]

As an update, after much testing it appears the ABS module is failing. As long as I release the brakes and allow it to reset it stops just fine. So now, BMW has been contacted by Capitol BMW and they may replace the unit and I pay only labor.
The reason for this deal is 53k in 26 months. The engine seldon gets cold.
I can easily live with that. New two year warranty on the unit.
It pays to do business with a dealer, let them make some profit so they can stay in business.
Just my .02

[LAF]

It pays to do business with a dealer, let them make some profit so they can stay in business.
Just my .02

+1 on this.

As I say they are my only advocate in a warranty situation. If I don't spend a little money with them to support them, what is to motivate them to support me?