Leak search on heat pump system. Pump down condenser and put 375 PSI on system for 1.5 hours. Did not drop any at all within that time. Check outdoor unit. Use bubbles to try to locate leak. Could not find leak. When I started the unit backup it ran perfect and the AC mode. Upon starting the Heat the circuit board outside gave me an error code flash 7. Which stated that the valve was responding but system was not operating properly. I put EEV through test and it said it was opening and closing just fine. I will need to get with Trane tech support to find out what revolutions can be taken.