Dear fiat forum members

Would somebody to tell me what this fault codes mean?
I have got just tested my fiat punto multijet diesel because the engine management light was flashing, coming back and on. The local garage did a diagnostic test showing the following code errors which come back even when they cleared the trouble codes. They charged me for 47 pounds and they have recommended to check the car with oscilloscope which would cost me 80 pounds.
The codes PO106 Barometric/turbo pressure plausibility
PO504 brake signal

Could somebody tell me what could be the problem before they rip me off with fixing or other things.

thank you very much
Alex

p0106 means your MAP sensor is faulty and giving a signal that can not be correct. you may need to replace the MAP sensor, but first check the hose on it for any splits or cracks as a simple leak can also be the cause of this error.

p0504 means there is a problem with the switch on the brake pedal. i often see this when the brake lights still work. the switch has 2 circuits which the ecu compares, this fault shows that the ecu is noticing a difference between the 2 circuits. the most common cause is a short in one of the switches 2 circuits, but a faulty switch is also a common cause.