isx12 cm2250 fuel pressure only builds if injector harness is disconnected

[num1enloe]

so ive got a 2010 pete 365 with an isx12 cm2250 that died on the highway.
whent customer called i drove out to take alook and found something ive never ran into before. the injectors are being supplied 5.4v at all times the key is on. which is apparently enough to crack them open. i discovered this by accident when doing the injector leak down test i had removed the harness for easier access to loosen the other end of injector supply line to pivot out of the way and install the cummins cap on the rail. i at first thought i had found the leaky injector. but than noticed i hadnt plugged that harness back in. i had an extra injector harnes laying around so i connected it and found between the two of each injector nuts i had 0.3v than i tested each one for voltage to a frame ground and found the 5.4v. i than tested the harness for shorts and found nothing. so i than tested the ecm directly with engine harness connectors disconnected and found the ecm was sending the 5.4v signal. am i overlooking something or is my ecm faulty?
ecm is fully updated and engine showed no signs of a weakening fuel pump prior to this last load of hay. ive tried reflashing the ecm but still it sends this voltage to injectors.