scoubix

The 5AS can be accessed (and the EKA read) even if the car has been unlocked with the key only. It's only the later Pektron unit that would need unlocking (either with remote or known EKA) to be accessed. At least that's what the T4 would allow you to do, never had the chance to test with pscan but I would imagine it's the same since this is down to the ECU internal coding to allow access or not based on car lock status.
You mention your car is a 1995 216. Do you mean an early mk3 Rover 200 (bubble) or a late mk2 (R8) 216 with the Honda engine? It is my understanding that the Honda-engined cars never had any form of EKA.