To summarize, even the PICKit3 (hardware+firmware) has voltage issue, the MPLAB IDE v8.92 doesn't care and doing well the job. Even I minimize the voltage limit to 3,458 (in settings) and get the output 3,13 V still the read/program process is going well. When I set it, the 'real' output voltage is 3,25 V (accordind to MPLAB) and the read/program process is going well without errors. In MPLAB IDE v8.92 the maximum voltage limit for my target chip is 3,599 V. An external power supply might be necessary. The target circuit may require more power than the debug tool can provide. When I set it, the 'real' output voltage is 3,25 V (accordind to MPLAB) and I get the same error '. In MPLAB X IDE v3.45 and MPLAB X IPE v3.45 the maximum voltage limit for my target chip is 3,5 V. I played a little bit with voltage (power) settings. Meanwhile I got some advises from Olimex support and the result is below: Of course everybody is choosing the easiest method. In the field I'm trying to have minimum of cables and connections, it minimizes the chance to connect something wrong. In field I always have power on the target. I tried on different MPLAB versions but still see the voltage difference about 0,3V between real output and set in power parameter.Р”Р„lso I tryed PICkit 3 with external power suplyer 7V and still see the same 'low' VDD on output pins. There is any callibration tool for PICkit 3 VDD ? Or what I'm doing wrong? How come? In power settings it is set 3,25V. If I disconnect the programming cable from board I see 3,07V. I measured voltage level between pin 2 and 3 on PICkit 3 and saw 2,97V. This could be due to the USB port power capabilities or the target circuitry affecting the measured VDD. PICkit 3 is trying to supply 3,250000 volts from the USB port, but the target VDD is measured to be 3,000000 volts. I was trying to program a PIC32MX250F128D without success.

Pickit 3 debug