Tacoma 2nd gen error code c1422 brake booster ?

if I apply more than half pressure on brake pedal I lose brakes and can hear a loud hiss /air release can be heard by brake pedal . I got error code c1422 but brake fluid seems fine pedal not stiff . In order to get brakes back I have to lift off and re apply half pressure to regain brakes .

 

Are your brake lights on when you are NOT pressing the brake pedal?
This is the first and easiest test.

As this is basically what that code means. (kind of)

 

No brake lights aren’t on when not pressing them . Brake switch is not faulty innova scanner shows it’s working

 

When you say you lose brakes do you mean the pedal gets hard or it goes to the floor?

Actually we need to see if they work, the code means it is seeing brake pressure increase but not seeing a signal from the stop light switch.

 

Brake pedal goes soft . It goes to the floor and can hear air escaping

 

That's interesting, hearing air escaping would suggest the booster was leaking but if that was the case I would expect the brake pedal to get hard instead of go to the floor.
You do have the vacuum booster (non TRD OffRoad) correct?

 

I do have a vacuum booster yes . Only time pedal goes hard is if I turn car off and press brakes twice .

 

I'm really not sure on this, the pedal going to the floor suggests a hydraulic failure in either the master cylinder or ABS module but the hissing suggests a failing booster. Then there's the code for the brake pressure sensor.
It's quite unusual for all this to happen at once, really need someone that's good with brake systems to take a look at it.