08 Vision has an intermittant Brake pressure issue. Lamp and chimes come on everyday just on the afternoon route. I replaced a sticking brake lamp switch earlier thinking that was the cause. This is the Bosch Hydro-Max system. Bosch trouble shooting... Brake indicator buzzer malfunction - Vehicle specific- -see service manual. WTF!?!
Well, I tell you what I did. I know this is not a fix but it works. I have a bus that a driver uses who is never absent. Well one day he was absent and the sub had the problem that you describe. I WAS able to duplicate it and could not locate the problem. The regular driver came back and got in his bus and I didn't know it. When he got back in I said you know that thing has a light coming on don't you? He said "no it doesn't". So after some back and forth what he is doing is putting his foot on the brake pedal before he turns on the key. That's the answer because I was able to make it do the same thing. Go figure! By the way this is on an '06
Found the yellow warning signal input wire had a cold solder joint at the ring terminal on the motor. It is also shared with the motor (red)wire from the relay. Funny how the motor worked but the reference didn't. I had to drive about 30 miles for it to screw up, pulled over, then I started checking the wires at the module. I found when I grounded the yellow through a test lamp the light went off and the buzzer STFU. Traced wire to the motor.
“The good thing about science is that it's true whether or not you believe in it.” Neil deGrasse Tyson
2008 Vision (Brake Pressure) ON (Fixed)
Posted - 04/29/2010 : 08:00:38 AM
