servo keeps running

[Tim Cullis]

The bike has been running fine, local urban journeys for the last week. All of a sudden, when I switch the ignition on, the servo starts up and won't stop. The red warning triangle is on and the brake failure light is flashing, however the braking is normal (i.e. not residual braking). So apart from the warning lights, the only thing that's wrong is the persistent whining.

The front brake lever is clear of the hand guard, the rear brake is making contact with the bendy metal strip.

The dealer says don't ride it, get BMW Assist to recover it to them, but I don't want to go through that rigmarole if it's something simple. So, any ideas?

Tim

 

[Wizard]

So, any ideas?

Right, who's going to ge the first smartarse with "Buy an 11xx" "Trade it in for a non-ABS" or whatever sad wee troll their infantile mind can come up with

 

[Wizard]

Tim, have you tried putting a meter across the brake switches to see if maybe one of them (probably the rear) is sticky? Or even check the brake light goes on/comes off smoothly.

 

[newman7096]

I had a problem with no servo at all recently but luckily managed to diagnose it myself.

The little metal brake light switch situated just above the rear brake lever had been knocked and had got stuck under the adjustment bolt. When I turned the ignition on and started the engine the it would show a brake fault however once I repositioned the metal switch normal service resumed.

I know its a bit different from your fault but it may be worth a check of the switch.

 

[Tim Cullis]

Brake lights operate smoothly. I've already checked the little metal brake light switch and it's making contact when the bike starts up.

Tim

 

[Cestria]

I'm not sure how the brake switches on the levers (that operate the servo's) are set up - if they are normally open or closed with the brakes OFF, but I would be finding out and checking both front and rear switches carefully. Hopefully thats where your problem is, crud gunging the switch up so it's not operating properly maybe or possibly an open circuit (wires or connectors corroded through maybe) if they are normally closed with the brakes off. If not I would think you are looking at controller failure which sounds expensive-hopefully for BWM. Good luck.

 

[Shep]

The bike has been running fine, local urban journeys for the last week. All of a sudden, when I switch the ignition on, the servo starts up and won't stop. The red warning triangle is on and the brake failure light is flashing, however the braking is normal (i.e. not residual braking). So apart from the warning lights, the only thing that's wrong is the persistent whining.

The front brake lever is clear of the hand guard, the rear brake is making contact with the bendy metal strip.

The dealer says don't ride it, get BMW Assist to recover it to them, but I don't want to go through that rigmarole if it's something simple. So, any ideas?

Tim

I had almost exactly the same symptoms on the last GS, it was a faulty ABS unit sorry mate, the only difference was that mine reset when the ign was switched off, it also cause the alarm to arm and operate as soon as the ign was switched off.

I'd check the switches very carefully, the rear light contacts for corrosion (not sure how that works but i assume some power is allowed to jump from rear light contact to the brake light contact, then somehow confuses the brake circuit, personally i'd get it recovered by BMW assist if its under warrantee, thrash the hire car to within an inch of its life, just to get your moneys worth

Shep