2001 lx470 with abs/vsc and buzzer

[grundsethp]

So I have the brake fault no one want to get but its a bit strange. The brake booster pump runs continuously so could it only be the brake accumulator that is bad. Anyone know how to check this? The reason I ask is the accumulator is much less expensive than the booster/accumulator or the whole assembly.

Any insight on diagnosis is welcome..thanks!

 

[grundsethp]

Fault code is c1256 and c1252

 

[happy the man]

grundsethp - howdy - having this same problem and wondering if you ever resolved it and if so, how? I replaced the pump motor and rebuild my master on my 98 two years ago. Unfortunately at that time I did not replace the accumulator. I'm currently getting a squealing noise now but the pump motor sounds fine to me. The squealing noise only occurs after the pump motor has run for several seconds.

I'm only guessing but to me it sounds like the noise starts when the accumulator starts to get pressurized. If you have any feedback or thoughts that might help out I'd love to hear them. Thanks and happy New Year!