'03 RT "brake failure" light is flashing rapidly upon start-up

[Joe G]

After a long day of riding yesterday, all of a sudden the "Brake Failure" light, upon start-up, started to flash much quicker than usual. Braking action was almost nonexistent at the foot pedal, and only moderately effective at the hand lever.

 

This had happened to me once before, and I found out that shutting the bike down and coasting, then starting it up again eliminated the light. And yes, the brakes did work right afterwards: I tested them individually before proceeding.

 

When this happened yesterday, I repeated this procedure, but the light didn't go out, even though I had normal braking power, so I continued on through the small town I was in. And then suddenly the failure warning light went out.

 

I stopped on the town's outskirts for a moment and shut the bike down out of habit. When I turned the key to "Run," the light started to flash at its regular pace, but then went into hyperdrive again. Did my procedure again, but it didn't work this time. Pulled over, cycled the bike through a few start-ups...nothing. The light continued to flash rapidly.

 

Pulled out, ran the bike up to the local speed limit ( maybe 25-30 ) and the light went out. I tested the brakes, individually and gently and I had brakes through both circuits, and at the normal level of effectiveness.

 

Got home, stopped for some food, and the bike did the same thing when I started it up. I shut it down, turned the key to the "Run" position, the light started to flash at its normal "slow" speed, but then sped up. At this point I had to grab for the hand lever because I was rolling backwards, something objects do here in The Hills of San Francisco. And the light slowed down to its regular speed!

 

Being the good scientist I am, I turned the bike off, and I repeated the process. Same result. Now, some would say that this is the definition of insanity...personally I think I'm a frikkin' genius! But Whiskey Tango Foxtrot is going on here?!

 

The search engine and I do not get along, not one iota. And I know that I can't be the first rider on this board to have had this happen to them, so if anyone knows the answer as to wtf is going on, I'd appreciate hearing it.

 

And I've already lubed the muffler bearings and bore gifts to Baal this week, so those answers are out!

 

Lemme know. Merci beaucoup.

[GlennW]

A weak battery can cause a brake system fault on startup. Once a fault is detected, the computer shuts off the servos leaving only residual braking.

 

Also, holding the brake on during startup can trigger the fault.

 

Hope this helps.

 

GW

[Boffin]

This could also be low brake fluid. Whatever it is though, you seem to hav a fault in a critical system. Is the bile still in warranty? If so its a no-brainer. Even if it is out of warranty, I would get the dealer to read the fault-codes out of the system - some will do this for free - so that I knew where to start looking for the fix.

 

Andy

[Turbodog]

I'll second Andy and Glenn. Low brake fluid levels or low battery power would be the first things I'd consider.