Nissan First P11, brake problem

Hello everyone. I introduce myself to this my first message. My name is Manu, a mechanic ex officio, hobby and obligation, for the reasons that most concern us.
I have a first Nissan, model P11, from 1999, 2.0 TD 90 hp with 224,000 km.
It is in good condition, I take care of everything I can. But he complains of small "diseases."
The problem I have is that the brake warning light is turned on, in the control box. I have made several checks. The brake pills are fine, from. And after., The brake fluid has a good level. I have come to verify that the light is turned on-pee when I accelerate and speed speed or speed.
I think the problem is in the brake depressor or the aspiration system that comes from the engine.
What do you think? Has anyone had something paared?
Thank you very much for your help, advanced.

Good compa, if the light to which you reference is in an except and looks like a white shot, is that of the brake booster that indicates lack of depression in the system, it is usually accompanied by a stolen brake pedal and in that case repair or change the booster. If it is the one that indicates ABS, there is no choice but to take it to a workshop and connect a scanner for ABS to know the problem.

Thanks for the response so fast.
My car has no ABS system. The light that comes on is the one that has the symbol of exclamation between two square brackets
(!), I think I remember, even if I will check today.
May it be a resident of the servofreno, or the empty tubes that reach it?
There are also times that the engine is being crowded at an intersection or semaphore, leaving it in the dead man.
Can it have something to do with the above?

Hello good!!!
I keep testing with my car, before giving hand to the breakdown without knowing where to do it.
I think I have eliminated the resident's breakdown. If the brake pedal (pumping) intermittently plants the light when the servo remains without pressure (bone without depression), the brake warning light is turned on and the few seconds goes out, when the empty pressure recovers.
The light turns on more easily when it accelerates and let the car retain the gear speed, sometimes the engine is covered, for example when stopping in a semaphor.
The pedal does not get hard at any time, only when I cause the loss of vacuum in the servo, voluntarily.
I don't know what you will have and whether it will be dangerous or not, to circulate or for the engine.
Does anyone have any idea?