mitsubishi electric air conditioner outdoor unit model PUHY-P200YGM-A

We have a vrf Mitsubishi that on heating the compressor is making a short cycle. It starts for one minute and stops for two minutes . we are suspecting that is low on refrigerant but we cannot overide the program so thu unit runs full speed to check the pressures. the indoor units are with a wireless remote and there in no falut code on them . actually the unit has no fault it is only not sufficient on heating . we added some refrigerant and the pipe temperature was improving so that is why we keep assuming that it is low on refrigerant .

Could you be so kind to tell us if there is a test run button to check the performance .? and how ?

read through this manual http://www.mediafire.com/view/?pgsc06lqx377plt
- run through the refigerant checks list- best option is to reclaim and weigh whats in
if its lost gas then pressure test and prove its integrity before recharging

Test run >> outdoor unit's SW 3-1 to activate (test run) and SW3-2 for ON/OFF entire system
Refrigerant adjusting mode >> outdoor unit's SW4-3 need to ON