Vehicle protection system unavailable

[ACE]

2006 Brera 2.2 manual

Request for assistance from the Brains Trust

The "Vehicle protection system unavailable" message has started popping up intermittently when the key fob is inserted in its slot to start car.
This is accompanied by the yellow steering wheel/key symbol on the dash.
Usually it is sufficient to remove the key and replace it for the message to disappear.

MES reports: "B1001 - Steering lock/unlock" ... and suggests checking for a "short circuit on actuator terminals"

The steering lock - the metal box attached to the steering column under the dash - has been removed, disassembled (there were no apparent physical faults or damage), cleaned (physical & contact cleaner), regreased (li), reassembled and replaced.
The lock was tested for locking functionality before complete reassembly. I.e. connected to car, powered up, but not bolted in - yet. The tongue in the lock retracts as soon as the key is inserted and pops out again about 5s after the key is removed from the lock. As expected.

On reassembly in the car, the fail message still appears - intermittently.

The two micro switches on the micro-board appear to be functioning. (Established by testing resistance across the switch poles - on vs off. The micro-board was separated from the main board for this.)

There is no apparent physical damage to the boards. e.g. no signs of heat or burning.

The large toothed wheel appears to move (i.e. rotate) just far enough to trigger its micro switch.

But the toothed wheel seems to require some force to make it rotate fully - especially towards the end of its travel, corresponding with it climbing up the cam.

So, if the wheel is turning; if the boards are good; if the switches are good; what else might it be that is causing the message on the screen?

And are the "actuator terminals", referred to above, the switches on the micro-board?

ECU connectors (beside battery) have also been treated to a dose of contact cleaner.