W210 DAS2 key question

[JeremyG]

I'm currently running a '96 W210 E230 estate with the DAS2 key (I believe) - rectangular, with the pop-out blade.

I bought the car with two keys, one of which has always been more reliable than the other at starting the car - both work fine at unlocking it.

Anyway, today one of my 5-yr old sons dropped the good key and - to his horror - it split open, spilling the circuit board, key blade and spring mechanism onto the floor (you should have seen the look on his face...).

I reassembled the key to find it would lock and unlock the car fine but would not start it. Then I noticed what appeared to be a further piece of broken triangular plastic on the floor - which on closer inspection was some sort of chip, stamped Philips and around 10mm long by 3mm thick.

I guessed this was the immobiliser chip but couldn't see any obvious marks on the chip or the key casing to identify where it should be located. So I just dropped it into the case under the LED on the circuit board and to my surprise the key now started the car perfectly.

So I'm assuming this is some type of RF device that disarms the immobiliser by proximity to the ignition lock; it is not connected directly to the circuit board or key blade. Can anyone confirm this is the case?

Cos my question at the end of all this is, is the RF chip OK rattling about inside the key case, or can I fix it with a blob of superglue?

Or is there a fixing point I've missed?

Thanks all,

Jeremy

 

[jberks]

If it works its fine. I'd probably glue it in place to prevent any damage though.
As you assumed, its activated by RF from the key switch so, so long as its in the right proximity it should be fine.

 

[ant500sl]

Another point with this system is that when the batteries start to get low the key will unlock the car but will sometimes not deactivate the immobiliser. It may well be that replacing the batteries will make your unreliable key work fine.

This is exactly what happened on my 96 c36, one key was fine and the other had a mind of its own. The dodgy key gets left in the drawer and when you need it for an emergency its even worse. Mercedes probably know this as they suggest keeping spare batteries in the glove box and have provided a keyhole in the passenger door so you can get to them.

 

[JeremyG]

Thanks for your quick replies. Have superglued the chips in place in both keys and now both work, and neither rattle. Job done!

(I'm wondering if the dodgy key was dodgy because the chip was moving around inside the key casing and was not always near enough the lock to be detected.)

 

[jberks]

Another point with this system is that when the batteries start to get low the key will unlock the car but will sometimes not deactivate the immobiliser. It may well be that replacing the batteries will make your unreliable key work fine.

This is exactly what happened on my 96 c36, one key was fine and the other had a mind of its own. The dodgy key gets left in the drawer and when you need it for an emergency its even worse. Mercedes probably know this as they suggest keeping spare batteries in the glove box and have provided a keyhole in the passenger door so you can get to them.

This is true on the single button keys but on the 'electronic' ones, treh batteries only work the remote locking. The immobiliser is operated via a transducer in the switch - hence why in spite of the chip not being attached to any power source, it still works.