Priority 1 brake warning light.

[Bob Holmes]

I have been getting a priority 1 warning fault system indicator on the dash for the brakes, and is as the manuals states “This symbol is accompanied by three warning chimes and then the big symbol is then replaced by a smaller one in the top left corner until the fault is rectified”.
However, within a few seconds of this happening, all red lights go off and it does this ever time, no other fault lights, just brakes, I have plugged VCDS into the car, no faults, pads are good, I have shorted out both fronts pads, no difference, hand brake works fine, it’s not every trip and can do it more than once in a trip, each time it does it, the fault never stays and VCDS shows nothing, fluid is good, servo works fine, car stops as good as ever.
If I corner really hard to the left I can normally make it happen 1 out 8 times but also happens with all types of driving and if I try the brakes while the fault is active they work fine and fault goes, if I don’t touch the brakes, the fault still goes. Pressing the dash “check button” not fault.
Can anyone help please?

[zollaf]

the thing about cornering wouldpoint me to something that changes whilst cornering and that thing could be the fluid level. is it full, could it take any more, could the sensor be a bit over enthusiastic. maybe work out if its a make or break sensor and either unplug it or short it out and see what happens ?

[Bob Holmes]

the thing about cornering would point me to something that changes whilst cornering and that thing could be the fluid level ?

That had crossed my mind but as the fluid has its owner indicator ( I think ) I had ruled that one out, however, the level is mid-way between min and max as I change the fluid regularly and saw no point filling up to the top only to suck it out again, thanks for your reply, I will put more in as I do corner to the limit of the tyres from time to time.

[Bob Holmes]

could be the fluid level. is it full, could it take any more, could the sensor be a bit over enthusiastic.

I did just that Zollaf, put another 100ml in and that sorted the fault, I guess it was just at the tipping point for the fault to clear it’s self so quickly, thanks for your help.