Mercedes W202 does not see the key in the ignition lock

Mercedes W202 does not see the key or how to clean the dust and repair the ignition lock

 

 

I'll start with the fact that the car does not see the key well and does not perceive commands to start: either it does not respond at all to turning the key in the ignition lock, or it responds with a delay, after a pause.

I shined a flashlight into the lock and saw an excessive amount of dust. And it seemed to me that the problem was buried right here - in the dust.

 

 

So I removed the lock, put it on the table and started to disassemble it...

 

 

 

I checked the contacts for oxidation, everything is fine.

 

 

 

I continued the inspection, in the process I unscrewed two screws from the front part of the lock.

 

 

The sides of the lock have clips that we pry up to separate the lock body.

 

 

Voila!

 

 

Now we start to disconnect the plastic from the board.

 

 

Soldered this joy in three points, the read coil (antenna) of the key, which cast doubt on my suspicions about the dust... Hmm, but I continued :-)

Let's continue, in three points, the reading coil, the solenoid that allows you to release the key and the limit switch, the so-called mikrik. As I understood over time, a mikrik that works when the key is in the slot.

In addition, it is also fastened in three places with three screws. Coincidence..? Do not think...

 

 

I continued to disassemble, at the same time investigated the operation of the mechanism.

Removed the antenna coil, the same clips as on the lock body.

 

 

After dismantling the antenna housing, the reason for the excessive amount of dust was visible almost immediately.

 

 

In addition to the dust, the mechanism that presses the microk when the key is present became visible, and it attracted attention because it had excessive wear.

But for now I decided to clean the parts of the lock from dirt.

 

 

Often, this dust gets on the photocells that read the position of the ignition lock, and the information about the turned key is not read. But this problem is more common for newer Mercedes.

In this case, everything was fine with the light and photocells of the board.

 

 

Now it's time for the limiter, mikrik, switch))

 

 

As it turned out, it did not press, and the reason for this was excessively worn plastic, which was an intermediary in this mechanism. Soldered 0.2 mm of plastic, filled everything with glue with a piece of pieced insulating tape.

After that, I put the lock back together and everything worked perfectly.

 

 

The reason was a worn out mikrik mechanism , which signaled the presence of a key in the ignition lock, and the lock itself ignored any actions and manipulations, whether turning the key or turning on the starter, because it did not see the presence of the key in the key receiver slot.