There is a small motor in the ESL, which in my case lasted 13 years, but the web tells me of much earlier failures. A sign of failure is the inability to start, but it might just start after retrying.
The carbon brushes on the motor wear out and knowing that the ESL is at he end of the steering column, you might just be lucky to get it started by hitting it.

1 Drive to a stealership for a AUS$2000 repair with a new ESL or into your garage for DIY. Changing the motor with a $5 Chinese copy or 50 euro original might do the trick to get the car started again? Watch lots of Youtube videos, incl. MIKEYZs, who shows you how to extract the ESL if the steering was not locked and to fix it in Part 2.

2 If you are unlucky as I was and started with a slowly dying motor until it finally died and left me with a locked steering wheel, then that presents you with more work. In that case the entire steering column has to be pulled out and the ESLs mounting bolt (10mm) has to be cut. The dying motor may have also upset the NEC security chip in the ESL and that means sending the ESL, ignition lock and key to Australian ECU Repairs or other electronic locksmiths to change the motor and the NEC chip and then to re-program the units. There is no need to remove the steering wheel, air bag, gauges to pull out the column, it is a two-man job to remove the cable while the column is half out.

3 Aliexpress/Fleabay sells you the motor, handle to pull out he mounting pins of the ESL and a cylindrical tool to remove the ignition lock, but one or two screwdrivers will do the trick, too. But the Chinese mail system is not operating at the moment as I found out. Cost to change the motor and the NEC chip is less than AUS$500.

4 Another solution is to dispense with the ESL altogether and send ESL, ignition lock and key to an electronic locksmith to add in an emulator. That emulator has the smarts (security checksums) copied from the good ESLs NEC chip or ignition lock and bypasses the security checks that way. If the insurance co. found your steering lock is no longer mechanically locking, then they will not pay out after theft. Australian ECU Repairs claims users with emulators have had to revert back to ESLs due to reliability problems?