'97 E420 - Won't Start - Related to Key? - PeachParts Mercedes-Benz Forum

jgl1 · #1 06-15-2002, 02:04 PM

1997 E420, 55K miles. Using the original master key (switch blade style, with central locking system IR transmitter), starter engages and spins motor readily but ignition system apparently disabled and engine fails to start.

Using a spare master (blade only, no transmitter or battery; obtained from M-B) motor starts readily.

Will renewing the battery in the original master key remedy this problem or is this related to a fault in the key's security chip. requiring renewal of the master key?

euro 287 · #2 06-15-2002, 06:17 PM

Most of the time the chip comes loose in the key, you can tell by grabbing the key and shaking it , you will hear something jingling around, thats the chip. The little red/green lights will flash on the mirror saying no authorazation for start. Just get a new key from Mercedes and throw away the old one.,

euro 287 · #3 06-15-2002, 06:19 PM

Sorry almost forgot something important, you will need to leave the new key on for about 90 minutes for it to program. It uses a rolling code. I believe if you want to pay the extra bucks Mercedes can code it there at the dealer with you car.

Gilly · #4 06-15-2002, 10:58 PM

You're thinking of a smartkey, MB didn't have smartkey until 98.
Gilly

jgl1 · #5 06-16-2002, 09:37 AM

Correct. 1997 W210s were not equipped with the Smart Key (DAS).

But they did have EIS (?), didn't they? Which is why a key copied at a locksmith won't work - the key won't have the required integrated chip.

Since the chip recognition system is apparently working (with the spare), all that should be required is renewal of the master key. Correct?

Or, have there been problems with the on-board chip recognition/start authorization system?

Gilly · #6 06-16-2002, 09:34 PM

EIS and smartkey go hand in hand-no smartkey, no EIS. The EIS is the module a smartkey is inserted in to.
You are confusing the EIS and smartkey system with DAS. DAS is Driver Authorization, which is any system MB uses to make the engine non-operable if an incorrect key is used. They used several systems. I have info in my library at work which gives the different systems used and a brief description of how they operate. If there is an interest I can transribe some of this info on this thread.
You are correct in your reasoning about the reason a key for a DAS equipped car needs to be ordered via the MB key facility.
I also believe you are correct in assuming you have a bad key, this is not shall we say "uncommon". If the system always works with one key and never works with another, I don't see a need to do any diagnosis, just order a key.
Gilly