Remember, the fuel pump operates upon key rotation to 'ON' until fuel system pressurization, there should be a whirring at the right rear wheel well underneath inside frame. Can you have someone press the interior lock/unlock button (upon command) a couple of times until the system can be reliably isolated as the right pump motor noise? Listen closely at the lower right rear bottom of the trunk (car not running), so you can hear how long the pump for the pneumatic locking system is/is not running? Since this also involves the passenger door (sometimes, correct me if I am wrong) it is like 180 is focusing on, an air leak in that branch line somewhere. I haven't seen (or remember seeing) a schematic of the tubing routes/ports so there may be a long way to go for that trunk actuator. A small leak may open/close the passenger door but being at a threshold where it sometimes doesn't open the passenger door actuator (but) in all cases the trunk actuator is starved for the necessary activation all the time. The dash button should work better than the FOBs, as it is direct wiring not effected by any interference or other EM/battery influences. If the dash door control is not working in one position (wasn't clear enough it operates the rest without problems in lock/unlock mode), you have more problems than a possible line leak.


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