1999 300TD...key switch is locked up
 

Can't turn on key switch. It's locked up. Key unit slides in like normal but can't turn it. Have played with it but can't get it to turn. Same thing happened couple of months ago, but after playing with it for several minutes it finally did turn on. It's been fine until now?


Another problem started several weeks ago, don't know if the two are related? Some time when I turn the key on and try to start it, it clicks like there is a battery problem, then when I try a second or third time it will start like normal? Battery charge is around 12.5V


Will appreciate any thoughts.


Bill

When you inert the key there should be a slidy/clicky sound which is the steering lock disengaging, does that still happen? If not first thing is try new key batteries

Battery voltage sounds good. Do the inside lite come on when you open door. If no, check battery cable connections.

This is a "DAS" failure - Drive Authorization System.

The key has a chip inside that communicates with the EIS (switch module). There is a passive RFID chip in the key nose but also there is an IR handshake that happens.

First things first, make sure you are getting proper voltage to the electronics - does the mileage indicate on the display when you open the door?

Check key batteries as suggested earlier. Try just taking the batteries out, wiping them (like with a cloth?) and reseating them.

Did you happen to drop or damage your keys? I have heard of this happening, where the key gets dropped and the internal circuit board gets a crack in it. Or of course if the key gets dunked in water you're doomed.

The solution for this, if you only have the one key, and it's damaged, is a tow to the dealer.

Why would the key batteries matter? I thought the batteries were simply for the remote unlock.

gps
 

bump

Batteries in FOB's are funny things. I had a similar situation with my 2002 VW TDI. The immobilizer started tripping not allowing the car to start. Tried several things and finally changed the FOB battery. It solved the problem even though the FOB worked the remote locks perfectly with the old battery. Go figure

This happened on my E300 last year. Changing FOB batteries did not work so I had to tow it to the dealer, leave it for two days till the new FOB came in and $265 later all good. Seems like over kill for a new key but thats what you may have to do.

Good luck.

Geez guys.

First off, key batteries have NOTHING to do with starting the car. The battery inside the key is for the unlock/lock function and that's it. You can take the battery out of the key and it'll still start the car.

There is a relationship between the key and the EIS in the car. When you insert the key into the slot on the dash, the car senses that key is correct, ''wakes up'' everything and allows you to turn the key to activate power to the car then start it as well.

Sometimes keys die just because they are old. Some die from dropping them, other times it just happens out of no where. It's totally random when and how this happens from what I've seen personally and researched. Keys are only programmed to your car and your car only. You can't buy used keys from eBay and ''program'' then or whatever term you want to use. They are only sold at the dealer and they take ordering keys very seriously. You need to bring the car to the dealer and the parts guy will need your license, registration and will probably walk outside to check random VINs around the car.

So what if you have two keys and the car still isn't recognizing them? You probably have an issue with the EIS under the steering column. This again is a dealer only part that can only be purchase and installed at the dealer. The last time I had to buy one a few years ago it was close to $1,000 for the job with the part being like $650. You don't need to buy new keys, the dealer can reuse the ones you have. The job only takes a day but the key needs to be towed the dealer if you use the manual method of putting it in neutral.

What you do if I were you is to test both keys. If you only have 1 key, good luck. It's going to tough to figure without spending money.

Transponder /induction coil come adrift from remote circuit board.
W210 1998 Smart Key Transponder Coil Repair - Mercedes-Benz Forum