On first impression, this SOUNDS like a pressure switch problem. It's like a nominal pressure is maintained while at idle, but a high pressure condition occurs when the compressor is spun at higher rpms.
Check the continuity of the A/C clutch cycling pressure switch and the A/C pressure switch.
Since the A/C compressor is cycling normally, you can rule out the A/C clutch control relay, diode, and field coil. These are the only things that connect to the PCM and control the A/C system.