Australian Car Repair Issues? Ask an Auto Mechanic for Answers ASAP
Hi and Welcome to Just Answer! Every time you insert key into electronic ignition switch you should hear ESL (Electronic Steering Lock) motor operate. If you do not hear that and steering is locked, then ESL has failed and vehicle Start is not allowed. It is unfortunate but it is quite a common issue for Mercedes.
electric motor is the one that fails not electronic board or software 90% of the times. Mercedes will not sell that part as it is brink of security and they are the only one to install, in witch case you have to row the car to MB dealer. But if you are willing to do it yourself you can purchase a motor from internet and replace it. motor cost is around $30 plus shipping charges, but labor can be challenging. You will need to remove steering column from vehicle and do some drilling in order to remove it from column and get access to replace motor.
Here is one of the videos you can find on youtube for motor replacement,
please reply if you have any questions,