1997 key repair - PeachParts Mercedes-Benz Forum

VW1300 · #1 08-08-2012, 10:13 AM

The switchblade key for my 1997 E300 had a broken case that was taped together when I got the car. It worked though - both the remote and the key itself could start the car reliably. REcently I picked up a cheap replacement case on ebay and I was going to transfer the guts and key of my old one into the new one.

The cheap replacement wasn't an exact fit for the guts, so I put everything back in the old one with some fresh batteries. When I did so, a little tiny chip fell out - it had a Phillips logo on it with a bunch of numbers. I'm guessing this is part of the driver authorization system perhaps - I put it back in where I thought it was and put the whole old case back together.

I went outside and started the car with my flat key. While the car was running, I pushed the remote button and it matched up to the lock system and worked fine. However, when I tried to start the car with the rebuilt switchblade key I heard a "pop" from the engine, and it cranked but no start. I tried again, same thing. PUtting the flat key back in started the car successfully.

It seems something related to the driver authorization system got damaged when I was messing around with the remote guts. Or perhaps I'm not matching it back up somehow. When I get home, I can take a picture and post the inside of the key and show exactly what I'm talking about - but just in case, has anyone dealt with something like this, and/or know if I can still fix this?

My bailout plan is to purchase a flat key from the dealer ($40) and attach it to the working remote fob and be done with it, but I'd like for the whole thing to work properly if possible.

Thanks,

Jeremy5848 · #2 08-08-2012, 10:20 AM

Without actual experience to go on (my very early 1996 E300D lacks DAS) I would nonetheless agree with your guess that the little chip had something to do with DAS. (Your flat key has a similar chip embedded in it.) Without DAS your car will not start -- you know that. Unfortunately, if you cannot get the switchblade key to work you will have to order a new one from a dealer and possibly have it programmed at a dealership. As the plumber says, "This not be cheap."

Jeremy

VW1300 · #3 08-08-2012, 09:40 PM

Jeremy:

Thanks as always for the W210 advice. I have searched to the ends of the internet for information on the DAS chip in the switchblade key and have had no luck. I'll call the dealer and see if they have any info, if not I'm on the hook for another key. Part of the problem of finding information is that '97 has the one-year-only setup of a metal cut key with the chip inside, in '98 they went to the so-called Smart Key which is very different. The '97 ignition may be the worst of both worlds - subject to both mechanical AND electronic failures.

By the way, I still haven't had any time to remove my crossover pipes to check the resonance flaps like we talked about two weeks ago - still getting that P0200 code. I have the two big gaskets to put back on, but work/family/other stuff has been crazy lately.

Thanks,

VW1300 · #4 08-10-2012, 10:20 PM

FOLLOW-UP:

Went to dealer service counter today and asked if they knew anything about the '97 DAS switchblade key. They told me that not only must the little chip be present inside, but the IR circuit board is also involved with starting the car. Makes no sense to me since the flat key has no circuit board and starts the car anyway, but perhaps the computer is smart enough to know which key is which.

They had no idea if it could be repaired, and I'm on the hook for a whole new key fob. I just bought another flat key because I'm cheap like that.

nelbur · #5 08-10-2012, 10:54 PM

When you placed the little chip back in the remote, did you place it up close to the key end. I believe the chip is interrogated by the coil just outside of the key cylinder, so you would likely want the chip as close to the coil as possible.

I have the same car and have had some keys decide to no longer start the car. The original valet key just stopped working for no obvious reason, and one of my flat keys stopped working when I drilled a hole where a key should have a hole. Both will crank the engine but they will no longer get the engine to fire. I have just had a new ignition cylinder installed, and have not tried the two problem keys since, but I don't expect any change as both turned just fine. After 220,000 miles the old remote key and the old cylinder had both worn so much it was hard to turn the ignition. The new flat key worked fine with the old cylinder. I found that a new cylinder was cheaper than a new remote key.

DAR2KMR2 · #6 08-11-2012, 12:23 AM

I too had a worn ignition cylinder and worn keys in my 1997 E300D and at almost 300k miles it became hit and miss on getting the car started with the 3 keys I had ..... took the car in to the shop and they replaced the ignition cylinder since it was worn and then I only had one key that worked all the time and two that would unlock the car but wouldn't turn in the ignition cylinder becasue they were too worn. Having only one key I thought it best to buy another .... so I went to the dealer and they wanted $250 for one key with remote. The parts guy made it sound like that was my only option until I noticed in the binder he used to look up the part number that there were a few "other" part numbers listed for my model so I asked him what those numbers were for .... then he admitted that I could just buy the blade and replace it myself .... so I asked him how much for the blade? He said $15. $15 rather than $250? Then he smiled ... yep its the best value around. So I bought two new precut blades, installed them in the remote myself, and now I have three functioning remotes with keys!

Jeremy5848 · #7 08-11-2012, 02:39 AM

That's unfortunate, but true, that some salespeople will act dumb and let you spend all kinds of unnecessary money. Then they wonder why customers don't come back.

An additional note on the ignition circuitry in these early 210s: although the 1997 model year has DAS and a transponder 'ring around the collar,' it still uses a mechanical ignition switch (you knew that, right?), the last W210 to do so. This mechanical switch has metal contacts that can burn or corrode over the years and miles. This happened to my wife's '96 (AFAIK has the same switch as 1997 except for the transponder ring) and it began to be hard to start. The dash lights would not come on (except for SRS) and the engine would crank but not fire. If you kept trying the engine would eventually start but something was clearly on its last legs. I replaced the K40 relay to no avail; the starter motor and solenoid also were OK. I eventually decided that it had to be the ignition switch.

The full story is here -- and I didn't bleed to death -- but that's another story. Bottom line, I removed the ignition switch (210 545 06 04) and took it to the dealer. Once there, the parts guy (fortunately I have made extensive efforts to keep these guys on my side) was savvy enough to recognize that my 210 didn't have the $400 electronic switch (from 1998 onwards) but rather the '96-97 mechanical switch. Even then he couldn't find the part number that was on the old switch but rooted around until he found an S-class that used an almost identical switch (129 545 02 04) and sold that to me for about $100. Problem fixed, car returned to normal.

I later took the old switch apart (not a difficult job) and discovered burned contacts in one of the main circuits. That was the cause of the entire problem. I cleaned the contacts and put the switch away as an emergency spare. If you run into a similar problem with your '96-97 W210 (or with an older Benz), you may be able to repair your switch and save a lot of money. You've probably read threads here about fixing window switches? This is much the same thing except that the ignition switch has bigger pieces that are easier to work on.

The learning for me -- and for you -- is that the '96-97 cars are orphans of the W210 series and the dealer's parts catalogs (EPC and all that) do not necessarily have the right parts. As of right now, EPC still shows the wrong ignition switch for my car's VIN and refuses to admit that my switch exists! Since most parts-counter people have it beaten into their heads that "the computer is always right," you may have a very difficult time. Friends or not, no way they would have listened to me if I hadn't had the old mechanical switch to shove under their noses. Be warned and prepare!

Jeremy