The steering lock will engage once the ignition times-out, assuming that the lock hasn't previously been disabled in the CCF as I did on my D4 and have also done on my L322.
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Or the starter motor has failed, I think it is possible to tow start a D3 (not sure about D4) or even push start it down a steep hill in low range, I haven't tried the tow starting on mine, but have the started it by rolling it down a steep hill low box 3rd gear, which is what it seems to go to by default. That was on tarmacadamed, metalled road, on dirt the gentler tow starting in high range may work.