Ohhhhh. Just thinking again, Also the "SLIGHT MISFIRE AT IDLE" also ties in with my theory, And The other thing that springs to mind is Common sense thinking about Testing supplies and earths to the ecu in the case is not proof of the ecu being faulty because you have lost Comms to the ecu. You Can still have all your lives and earths to the ecu, The ecu appears Dead and suddenly comes back to life after several minutes of being left to cool off. Its all down to Electrical interference.

P,S I Might also be talking coblers.