I would like to tell you about one of the diseases of Mercedes cars – steering lock (ESL).
The Mercedes access authorization system in w204, W207, W212 includes a steering lock or steering latch (ESL, ELV). Accordingly, from its name it is clear that it performs the function of locking the steering shaft, when removing the key from the ignition. The blocker was installed on older models, but had a different processor and everything there is simpler, so this is a separate topic.
This way the ESL looks like
Due to the design features of this element is not very durable and brings great trouble to the owners of these cars. If the steering lock on the car is faulty, the ignition does not turn on, but it could be opened and closed with a key.
At diagnosing the car you could notice the following error codes A25464 , A25407, A25408 , A25409 etc. Sometimes even difficult to distinguish the fault latch from malfunction of the ignition switch, so leave it to the professionals.
What should you do when the steering latch is broken? There are several ways to fix this problem:
1. Give the car to dealer for repair, they will order a new latch and a programming key from Germany (about a month of waiting and a whole bunch of money).
2. Repair of the blocker, replacement of the motor, cleaning, lubrication (the most cheapest variant). Sometimes it is not possible to resolve, when the lock is locked electrically, usually occurs when the latch tab is locked in the middle position, or after repeatedly attempts to start with a faulty latch.
The following equipment can be used to restore the electronic part of the latch: https://carscanners.net/product/mercedes-esl-doctor-renew-repair-w204-212-164-esl/
3. Installation of the emulator instead of the steering latch, the most durable way to repair and average price. At the same time, the steering wheel will not be mechanically blocked, the electronic emulator completely simulates its operation. Safety of a car does not suffer, since on more recent models the blocker simply is not present.
I usually recommend to install the emulator, it is not necessary to bring the car to the service and you can just bring the ignition lock with a key and latch, these elements could be connected on the table and could be diagnosed without a car.
The following equipment can be used for program ESL emulator: https://carscanners.net/product/mb-clinic-all-in-one/
4. I also sometimes make a motor replacement, but there are some drawbacks of this method – latch will be noisier and sooner or later it will fail again. In short cheap and cheerful, mainly for cars for sale…