I have started my BEW with the cam sensor unplugged. It just takes a few more revs to start. Not sure why you had your experience Frank. The BEW can run on crank sensor alone. The BRM can run on either the crank or the cam sensor.
What can happen is if the Cam and crank sensor disagree, the ECU can get confused on the timing and refuse to run on either the BEW or the BRM. I have had one PD that would not start until I unplugged the cam sensor. Leaving it plugged in caused more problems.
Yes Poopie is right on changing out the sensor. It is a pain but can be done with the belt in place.
If the cam sensor and crank sensor disagree too much, and the ECU meets certain criteria (who knows how the logic is set up?) so it can tell which is in error, then it will change block 43 field 2 (torsion=cam to crank timing) to a default 0.0, throwing out the cam sensor input, and continue to run.
What really can foul it up is a constantly changing relationship between the crank and cam. One PD came to me barely limping along, running very poorly. The problem was excessive slack in the TB, causing rapidly and constantly varying relationships between the cam and crank.
So jettasetta, I would always replace the TB on a car I bought used, unless I knew for a fact that all the proper parts were replaced and knew the source of the parts, and who did the work. This just makes sense, to avoid a crashed head from a TB failure. I have had three cars come to me with very very cheap chinese copy timing belts on them, bought from prothe ( a very cheap parts place out of NC), one of these belts had broken in less than 10k, the others were very very close to breaking - badly cracked at each belt tooth.
In your case it is possible for this to also cause the code you are getting if there is slack in the TB.
This code is usually most likely from bad wiring, then bad sensors - either crank or cam, if the timing is properly set and the belt tight. In the ECUs logic the cause has been attributed to the cam sensor, but remember that it sees this as implausible because it compares it to the crank sensor.