05 GS ABS and Speedo failing

[mickb]

2005, R1200GS, 27,000 miles, servo and ABS brakes...

A couple of days ago on my way to work I noticed the ABS light had started flashing fast (4Hz), the red warning triangle was on and that the speedo had stopped working (fallen to zero). I pulled over, turned the bike off and then re-started it. Everything was okay for a few mins then the same thing again!!!

As well as the red triangle of death, flashing ABS light and no speedo there seems to be no servo assistance to the back brake when it does this, also I can hear the servo working continuously even with no brakes applied.

I’ve been out again tonight to do a bit more checking and the problem seems to happen mostly when I use the brakes and come to a halt. As the cockpit lights up the brakes fade away (I guess the servo assistance packs in) but very suddenly the front brake slams back on like a real SOB and crams my nuts into the tank, I tried it a few times (careful with the nuts) with the same result. I’m sure the brakes slamming back on isn’t me over compensating when the servo fades, scary.

A bit of a play in the shed with the bike on the side stand and it does the same trick after a few pumps on the front or rear brake levers, even with the ignition on but no engine running. Turn it off then on again and all’s fine for a while.

Battery/voltage is fine, terminals are tight, quick check on the rear wheel speed sensor wiring and brake light switches all come up good. Brake pads front and rear seem okay too.

All the electronics/computers were checked at Pidcocks in Nottingham without fault and the ABS software was updated a month or so ago (V.12 I think).

I was told all the brake fluid had been flushed and replaced just before I got the bike 3,000 miles ago at the 24,000 mile service.

Brakes loosing servo assistance and ABS is one thing but I really don’t want to experience the fade then slam back on at any sort of speed or round a bend.

There seems to be a few threads on a similar note to this. Have BMW owned up to anything? This could be deadly!!!

Any ideas ?

 

[Ali-bear]

There was a similar thread recently.

Apparently some swarf can build up on the rear wheel speed sensor over time (its magnetised). Solution is to disconnect wire, remove sensor, clean swarf off it and put everything back.

May not be this but its worth a try.

Welcome to the site

 

[John Armstrong]

There was a similar thread recently.

Apparently some swarf can build up on the rear wheel speed sensor over time (its magnetised). Solution is to disconnect wire, remove sensor, clean swarf off it and put everything back.

Think similar things happen on the F650 single as well.

See here: http://faq.f650.com/GSFAQs/SpeedoABSSensorFAQ.htm

 

[mickb]

Could be the sensor I guess.

It’s only about 2,000 miles since the rear wheel gear box popped its outer seal and I changed the seal, cleaned the sensor and changed the oil.

There were quite a few fines on the sensor then but I guess if the box is producing enough metal in 2,000 miles to confuse the sensor that the box is probably on its last legs. It feels smooth enough though.

I’ll have a look anyway, and post what I find, thanks.

 

[Charlie]

Had a similar problem on my 05.

When my switch gear failed I went to take it to the dealership and found myself riding without speedo or rear brake. (Luckily I didn't experience the fade and subsequent brake slamming on you describe). They ran a diagnostic and found nothing wrong (makes you wonder what a diagnostic actually diagnoses) and guess what, it all started working fine again. Since then I have put a new battery in and (touch wood) haven't experienced it again. Don't know if one of those clever GS911's would tell you anything but may be worth tracking one down.

 

[mickb]

Hmmm. Back wheel out, cleaned the sensor, which had a few more metal fines on it, put it back, bugger, same problem but it only did it once. I've been faffing in the garage for an hour or two and can't get the problem to repeat again.

I'll try it on tarmac tomorrow. Nuts at the ready!!!

Hope it's okay as my local dealer, Pidcocks in Nottingham say they can't fit it in 'till a week on Saturday.

Watch this space...

 

[Greybeard]

I had exactly the same symptoms on my '05 GS a few weeks ago. Are you sitting down?

When I took the bike to the local dealer they diagnosed that the ABS modulator was faulty. The bad news is that a replacement part was £1,200 - yes one thousand two hundred. Luckily although my bike was a year out of warranty BMW offered the part free of charge (after a manual goodwill request was made by the dealer - the bike was slightly overdue for a service) but I paid for the labour (£355) and got a 2 years parts guarantee as a result.

If you have had the bike serviced according to the schedule (particularly with reference to the ABS unit / fluids) then I think you should be able to get the part under goodwill arrangements automatically.

Good luck!

 

[nedflanders]

This was exactly the same fault that I had with my bike when it was a year old, it only happened after alot of short runs, I had to ride through town to get to work so the servo was getting alot of use with slow riding etc. Took the bike to the dealer and no fault was recorded in the ECU, turned out that if the battery is low on power(voltage could be OK, mine was but the battery could still be crap under load) the first thing to stop working is the speedo and the ABS light will come on. My advice is if your doing alot of short runs put it on a battery charger overnight, take it for a decent run or if your running alot of accessories get a better battery. After fitting a new battery when the original gave up(and rewiring the intercom so the bluetooth wasn't permanently on) I've never had the fault again.

 

[bezzer]

Ok this may be of no help. I had the same happen to me last summer. The cause. After ringing the dealer and being scared to death by the abs sensor price was...... The handguard had slipped slightly and was just touching the brake lever. Hence the brake was always being applied. Might be something to check. Could be a very cheap cure

Cheers

Nik

 

[mickb]

Getting closer...

I've checked the hand guards and brake switches, they all seem fine and dandy. Battery voltage is okay at 14.odd, I only changed it a couple of months ago for a ‘dogs dangleies’ Odyssey P535 so I hope it’s still good.

Pidcocks have managed to find me a slot at 2 PM today instead of next Saturday, so hopefully I should know what's up before the day's out.

 

[mickb]

Since I cleaned the rear wheel speed sensor the fault has only happened once, on the first start up after I re-fitted the sensor.

Rode it to the dealers and it’s been on the diagnostic computer, hmmm, “no specific faults found”. The guy showed me a couple of general failure reports on the ABS but nothing that was specific enough to tie it down.

So it may have been the rear wheel speed sensor that I took out and cleaned off that fixed the problem. Strange though, if it was the sensor, why did the fault also happen with the bike started but stationary???

So I’m left in a bit of a “suck-it-and-see” mode. I just hope it doesn’t decide to do it again while I’m bogging round a bend with the anchors on. This really P%$£^& me off with regard to confidence in the bike, ‘cos I think it’s a great piece of kit.

I’ll update if anything else happens on the subject (presuming I’m don’t end up arse-over-tit in a ditch when / if it happens).

 

[mickb]

Well, it's happened again, back to the dealers and turns out that the ASB modulator is failing.

The dealers have been great though, replace it quickly and got BMW to foot the complete bill, thank god, it came to £1,500.

Just hope that's the last I see of the problem.

 

[Greybeard]

... turns out that the ASB modulator is failing.

The dealers have been great though, replace it quickly and got BMW to foot the complete bill, thank god, it came to £1,500.

Sounds familiar... good that you got the parts and labour paid for

 

[luckylucian]

Well, it's happened again, back to the dealers and turns out that the ASB modulator is failing.

The dealers have been great though, replace it quickly and got BMW to foot the complete bill, thank god, it came to £1,500.

Just hope that's the last I see of the problem.

Did you have an extended warranty or was this a goodwill gesture from BMW?