WBO2 heater problem

[PIC]

Hi. I have installed second hand vems (v3.6) and now i have problem with WBO2. It seems that the heater does not work. When i turn the heater on from VemsTune > Tools > WBO2 Calibration > Start Cal. or from Terminal program with mde02 nothing happens. The sensor has 13.5V on pin 3 and on pin 4. I tested the pin 4 with scope and found no negative pulses. Then tested the fet Q18 gate and it has 0V all time. Then tested at processor pin 33 and still nothing (0v). How could i be sure that the heater is turned on? May it be that the processor is dead?