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1998 E320 Key does not work after car batter change

9K views 30 replies 7 participants last post by  dhlii 
#1 ·
The battery died in my sons 1998 E320 Wagon.
After replacing the battery The key will not turn in the ignition switch and the dash says "Take Key"

What is the procedure to make the car and key happy with each other again for a 1998 E320 ?
 
#4 ·
You need someone to come and determine whether the EIS or the key causes the problem. A little gizmo will determine that.

In the meantime, you can check the key infra red operation by holding the key tip towards a digital camera or smartphone in camera mode, and press any key.. You should see the blinking LED when a key is pressed at the screen. Your eyes will not see the infra red light but the camera does. If no blinking light, possibly the key is bad.

There is really not much you can do, other than have the car towed to the dealer and let them diagnose, and order a key, if the key is bad, or find someone who understands these issues to come to your place for diagnosis.
 
#10 ·
You need someone to come and determine whether the EIS or the key causes the problem. A little gizmo will determine that....

There is really not much you can do, other than have the car towed to the dealer and let them diagnose, and order a key, if the key is bad, or find someone who understands these issues to come to your place for diagnosis.
If every time, the battery died / disconnected and then replaced /reconnected, the EIS failed, we would have a mountain made up of bad EIS devices :). The EIS has the smarts to detect low / high battery conditions and should be able to protect itself. I recently scanned my EIS just for fun, and there were two stored codes. "Battery voltage too high", and "Battery voltage too low", indicating that the previous owner had some issues with the battery.

Typically if the key is "temperamental" in the first place, people apply force to turn the smart key, and this makes the matters worse, and turns the intermittent failure a permanent one. The good news is the key can usually be repaired. I did repair my own key and few other keys, after diagnosing that the key is the problem.
Just for clarification and not to start any arguments, your statements above are contradicting & confusing to say the least. :confused: Your initial suggestion was to have "someone come and determine whether the EIS or the key causes the problem" then it appears to suggest that there is nothing wrong with the EIS - "If every time, the battery died / disconnected and then replaced /reconnected, the EIS failed, we would have a mountain made up of bad EIS devices :)

Just late last year I had the EIS replaced on one of my cars because of "intermittent" loss of communication.:( This is after almost 13 years of owning the car. After replacement, The OLD keys still worked on the new EIS. One of the true enjoyment of owning these vehicles is the "like new" ride you can achieve with a minimum of maintenance and replacement of critical parts. My cars are purchased brand new and are "keepers" so any repairs I make are strides toward making the vehicles "show quality" and are considered investments.

As a matter of fact, yes, there is a mountain of faulty EIS, simply because they can be repaired. NOT in America, but Canada & UK have reputable places that fixes them. Most are shipped overseas to China and the Philippines to be repaired & sold again as surplus parts. PLUS the fact that they will occasionally fail if you kept & drive your cars long enough, not because of simply disconnecting/reconnecting batteries. In conclusion, EIS are repairable while fried smart keys are not. If they are, I would like to know how.:dunno:

Physical repair of keys is possible like swapping a bad fob shell with a replacement shell - just remove the PCB carefully & you'll have a perfect working key again. I have done it before. OR upgrading to the nice looking chrome key from the black plastic key, but requires transferring the EEFROM chip in the process. There are places that claims to be able to fix them but may require some specialty tools & equipment like a hot air station needed for carefully soldering, etc.

For the benefit of others on the forum and for reasons unknown to me, can you tell us how you diagnose and repair a faulty or fried smart key as you stated? :)
Thank you.:beerchugr:
 
#5 ·
"Take Key" usually means bad key or ignition lock. Try to use the other key & see if it starts the car. If both keys fail, something happened in the process of removing/installing the new battery. :( Without pulling codes, I will suspect a bad EIS. If the EIS unit becomes faulty, the “Turn & Start” function will be de-activated and the module will be locked for security purposes. This will stop the vehicle from starting. It is very unfortunate but also a very common problem as there are many reasons why these units are failing – most are due to human error. Some of the most common reasons are jump starting while key is inserted in the ignition, power surge & very low battery voltage. These can cause memory loss to the EIS module and it cannot be repaired or re-flashed even with using the Mercedes STAR diagnostic system. Sad to say, the only solution will be to replace the EIS with a new unit which can work out to be expensive when working out the total bill with programming and labor. :|
 
#7 ·
The most logical advise is to have it scanned using SDS to determine the real cause. :)
The risk with EIS is sequential failure, because it is an authorization device which is responsible for allowing many devices to function, such as the engine, the keys, RCL, shifter, etc. A sudden EIS failure will interrupt the functionality of these components. :(
 
#8 ·
If every time, the battery died / disconnected and then replaced /reconnected, the EIS failed, we would have a mountain made up of bad EIS devices :). The EIS has the smarts to detect low / high battery conditions and should be able to protect itself. I recently scanned my EIS just for fun, and there were two stored codes. "Battery voltage too high", and "Battery voltage too low", indicating that the previous owner had some issues with the battery.

Typically if the key is "temperamental" in the first place, people apply force to turn the smart key, and this makes the matters worse, and turns the intermittent failure a permanent one. The good news is the key can usually be repaired. I did repair my own key and few other keys, after diagnosing that the key is the problem.
 
#11 ·
No arguments:) just discussions:)

I do not think there is a conflict.. The post from the OP is just saying that the battery died and replaced and now the EIS and the key do not mate. IF that is all that happened, and the EIS and key worked perfectly prior to battery failure, there is no reason why the EIS or the key should fail PROVIDED that proper procedures are followed. If they did fail, there would have been a general recall from MB as, every car eventually needs a battery change.

Unfortunately, we do not know whether the OP has had problems with the key / EIS before, or everything worked perfectly, whether the car was attempted to be jump-started prior to towing , whether the key was in when connecting / disconnecting the battery, and whether any attempt was made by someone to "fix" the key or the EIS. Without knowing the history of actions / operation, it is not "remotely" possible to say if it is the EIS or the key. So more details are needed, and that is what I asked.

Regarding the diagnosis, I have a device that detects the application and removal of the energy field that powers the key. Based on the field presence / absence and timing, I can get some idea where the problem lies. Sometimes the problem is the ESL (the steering wheel lock). If the ESL does not talk to the EIS, the key will not turn either.

The first and second generation keys suffer from electrical problems around the energy pick up coil (loose coil, broken trace(s), solder joints etc.). These sorts of problems are typically repairable. I suspect the OP has a first-gen key like mine. I do not transfer chips, but there are people on these forums who do.
 
#12 ·
No arguments:) just discussions:) ............

.......Unfortunately, we do not know whether the OP has had problems with the key / EIS before, or everything worked perfectly, whether the car was attempted to be jump-started prior to towing , whether the key was in when connecting / disconnecting the battery, and whether any attempt was made by someone to "fix" the key or the EIS. Without knowing the history of actions / operation, it is not "remotely" possible to say if it is the EIS or the key. So more details are needed, and that is what I asked.
YES, of course :D :thumbsup:

And I completely agree with what you said "Without knowing the history of actions / operation, it is not "remotely" possible to say if it is the EIS or the key.

That is why I responded with a logical advise below, as follows:

The most logical advise is to have it scanned using SDS to determine the real cause. :)
The risk with EIS is sequential failure, because it is an authorization device which is responsible for allowing many devices to function, such as the engine, the keys, RCL, shifter, etc. A sudden EIS failure will interrupt the functionality of these components. :(
I hope the OP (@dhlii) comes back & updates us with details once the issue has been resolved :smile so we can all learn from his experience :laugh :givemebeer:
And thank you for the clarification :thumbsup:
 
#13 ·
Amidst all of this uncertainty (cars/keys/world) the CRAZY thing is running around with just 1 key.

When you only have 1 key and you have issues turning key/starting car, it is MUCH harder to identify the issue.

When you have 2 keys and ONE of the acts funny, it's obvious.

When you have 2 keys and they BOTH stop working at same time, it's probably not the keys.

I just got back from a road trip to Palm Springs. As usual, I took my 2nd key and left it in the hotel safe. If I had dropped my original in the desert sand, or the hotel pool, or spilled a drink on it, I was covered. I can not understand going through life with just one key. Seems like the recipe for constant anxiety.

Drop the $300-400 and get a 2nd key. When you start having EIS/Key trouble it will be very easy and quick to know what direction to go in.
 
#14 ·
Amidst all of this uncertainty (cars/keys/world) the CRAZY thing is running around with just 1 key.

When you only have 1 key and you have issues turning key/starting car, it is MUCH harder to identify the issue.

When you have 2 keys and ONE of the acts funny, it's obvious.

When you have 2 keys and they BOTH stop working at same time, it's probably not the keys.

I just got back from a road trip to Palm Springs. As usual, I took my 2nd key and left it in the hotel safe. If I had dropped my original in the desert sand, or the hotel pool, or spilled a drink on it, I was covered. I can not understand going through life with just one key. Seems like the recipe for constant anxiety.

Drop the $300-400 and get a 2nd key. When you start having EIS/Key trouble it will be very easy and quick to know what direction to go in.
Logically Sound Advice :grin :thumbsup:
 

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#16 ·
Sometimes, the OP would come back with a "Oh by the way,............." to tell the whole story. Till then, we can just keep guessing.

Typically, the PCB track gets cracked at one side only, So if you take the key out, and turn it 180 degrees and re-insert, it can start the car before the problem crack progresses. The torsion as you turn the key, separates the coil lead from the track, so no power is generated, when you re-insert the key as described above, the torsion pushes the lead back into the track, and, and with some luck, the car starts. This is a tell-tale sign of a cracked PCB track for this particular type of key (gen 1). For Gen 2 keys, the pick up coil core breaks, and the coil dangles inside the key till the coil wire breaks. Of course there are other failure modes.
 
#18 ·
Well the "OP" is back.

First the driver of the car is my 18 year old son, who I love but is not mechanically or automotively inclined in anyway.

The "history".

The car belonged to my father's business long ago. Keys got lost constantly.
It is my understanding that the car will only recognized 8 Keys ever and the current key is #8 - someone please correct me if I am wrong,
The other 7 were lost by my fathers employees a decade ago.

Yes, I would love to have a 2nd key. I have not done anything about it - beyond telling my son that if he loses the key it is going to be really expensive.

After the business closed my father drove the car for a few years. Then he bought a 2013 ML350 he was going to trade the E320 in but they offered him crap - might have had something to do with the deer he hit.
Anyway he bought the ML, gave me the E320 - I repaired the suspension damage - deer did little body damage.
And when my son got his license it was passed down to him. It is a good car to be driving if you are in an accident.
I was rear ended by a volvo in a 1994 E320 and I had about $500 in damage and drove away the volvo was totaled.

At times I what to send the ECU to one of those places that bumps up the horsepower - and ask if they can cut it in half - this is too much car for my 18 year old.

He drives it to work about 3 days a week. Work is about 5mi away. That is close to all the driving he does.
That is pretty hard on the battery. So it was not surprising when this winter the battery failed.

The car was not jumped, no
It died at home and having lots of older cars and tractors - and parents and inlaws who have died and left me all their crap I have lots of tools - including 4 battery chargers - one is even really nice.

Anyway it was charged - over night, and over night and over night ...

After several days of charging we still could not get it to start.

I do not beleive that anyone attempted to start the car with a charger connected - but there is an 18year old in this story, so anything is possible.

Anyway after several days of charging I tested the batter and was reading 11.7 volts - so I had my son take it to Autozone to see if they could test/charge it and if not get a replacement.
The declared the battery dead charged way too much for a replacement.
That was installed and when we attempted to start the car the message panel said "take key"

I know that the key was not in the car when the new battery was installed - because I was there.


So that is the "history"
 
#19 ·
Now about me.

I am not a mechanic or a MB expert. But I am also not a complete noob.

I swapped an engine in a 1980 Honda CVCC when I was much younger - and the car ran for several years afterwords.
But I am not doing that ever again.

I can change a wheel bearing or replace the gaskets on the air suspension pump on my Audi.

Professionally I am an embedded software developer, and I work for my self, so I got all those tools like hot air soldering irons etc.
Though I am 58 and big SMT components are more than my eyes can manage - though otherwise my electronic skill level is high.
Not that of an EE, but still pretty good. But it is not something I do every day.

I said I work for my self - well that means I am poor. That is not really true, but I do not live in Silicon Valley. I live in "pennsyltucky"
I like it here. I have two acres in the woods and live in a home office that I designed and have been building slowly for the past decade.
But where I live is not a hotbed of embedded software development.
So I live off of consulting work - I get very well paid for that - when I have work, which is about 1/3 of the time.

About half my work in the past 5 years has been on HMI's for agricultural and construction vehicles - though I did one project involving Diesel Busses. So I know my way arround CAN and J1939 - and I have CAN equipment and software.

But there is a difference between speaking fluent CAN or pretty good J1939 and speaking fluent car or Mercedes.
I can hook up a BBB (BeagleBone Black) and a PCAN and tell you what the speed of the right front tire of your car is.
But that is not the same as reprogramming an E320 ECU.

Oh, and the money thing means I am not going to spend several thousand dollars trying to fix a nearly 20 year old E320.

Frankly, I would think that would be understood here.
Are there people who can chose to own 20 year old MB's who can afford to send them to MB for repairs ?

I would love to make my Son deal with this - it is his car, and I have work right now.
But did I mention he was 18 ? If I leave it to him the car will never move again.
 
#20 ·
So I am after some help diagnosing this.

There are lots of things I can do, and though I would like to have the car running yesterday - I have more time than money.

What I am particularly looking for help is isolating the problem.

I can probably manage to transfer the eeprom or whatever has the magical coding from an old key to a new key if that is the problem.

But playing arround with the key is going backward if the problem is the EIS or the ECU.

Oh, I forgot that in the "history" The car has been reporting "check engine electronics" for probably a decade.

There has been alot of advice in some of the posts. But it is all over the place and I need to try to isolate the problem before desoldering chips from the Key or trying to find somebody to clone my ECU or ....

I am gathering the EIS and the Key are at the top of everybodies most likely culprits list - would that be correct ?

If I pull the DTC from CAN/J1939 am I going to be able to tell whether it is the Key or EIS ?

Am I correct that the car will only recognize 8 keys - without resorting to electronic hacking of the vehicle ?

Am I correct that the EIS is where the Key programming is stored ?

It appears there are people who do key reprograming of EIS's - can I get my EIS "cleaned" do that I can add more keys ?

Can I verify that all the Key slots for my EIS are used ?

If the EIS is dead can I buy another off ebay and find someone to clone it from the dead one ?

If the key is dead does that typically mean - totally dead, or is it still possible to move a chip to a new key and recover ?

There are probably other questions and I probably have not asked the right questions.

But the first step is to isolate the problem - so given the level of expertise I have described how do I do that ?

Some of the questions imply that I have read some things on this on the web and have guesses as to the answers.

But I am here asking people who hopefully know more than I do about MB's

Though I am begining to think that I am in the wrong business. That I might be able to pay my mortgage if I learn how to reprogram ECU's and EIS's and .....

And I get peved when I am told I need some 50K software hardware combination to reprogram some car computer.
I wrote the software to do that for tractors and skid steers and ....
It is not that complicated. The hard part is getting the secret knowledge needed.

And even if you can not get that. reprogramming most programmable chips is not all that hard either.
The hard part is knowing what to put in or take out.
 
#23 ·
So I am after some help diagnosing this.

There are lots of things I can do, and though I would like to have the car running yesterday - I have more time than money.

What I am particularly looking for help is isolating the problem.

I can probably manage to transfer the eeprom or whatever has the magical coding from an old key to a new key if that is the problem.

But playing arround with the key is going backward if the problem is the EIS or the ECU.

Oh, I forgot that in the "history" The car has been reporting "check engine electronics" for probably a decade.

There has been alot of advice in some of the posts. But it is all over the place and I need to try to isolate the problem before desoldering chips from the Key or trying to find somebody to clone my ECU or ....

I am gathering the EIS and the Key are at the top of everybodies most likely culprits list - would that be correct ?

If I pull the DTC from CAN/J1939 am I going to be able to tell whether it is the Key or EIS ?]

If the key is not turning you will not be able to connect an OBD2 scanner and read the codes (not engine related codes anyway, as the ECU is not powered up, so no communications). You need to be able to turn the key first. For EIS related codes you "may" be able to read codes from the EIS but only through the 38 pin diagnostic connector. The EIS is powered up and woken up when you insert the key. But you need a special type of scanner to read the EIS data. I never tried this with the key not turned.


Am I correct that the car will only recognize 8 keys - without resorting to electronic hacking of the vehicle ?

I thought it is like 3 rows times 8 columns but I may remember it wrong.
In any case, if the keys were made due to key losses (as declared), they may have been erased, due to theft presentation measures​

Am I correct that the EIS is where the Key programming is stored ?

One of the places, but the EIS also needs to match the ECU and the ESL, as well as the keys.​

It appears there are people who do key reprograming of EIS's - can I get my EIS "cleaned" do that I can add more keys ?

I am sure you can.​


Can I verify that all the Key slots for my EIS are used ?

If you can read the EIS data, it will tell you key slots status​

If the EIS is dead can I buy another off ebay and find someone to clone it from the dead one ?

You can get the chips transferred provided that the chips are OK,​

If the key is dead does that typically mean - totally dead, or is it still possible to move a chip to a new key and recover ?

No, it can be partially dead (remote only, or ignition only) or totally dead (chip problem, common power circuit problem)​

There are probably other questions and I probably have not asked the right questions.

But the first step is to isolate the problem - so given the level of expertise I have described how do I do that ?

You need to start from somewhere, and I would start from the key as I described previously. You can make a tool to try to isolate the problem too.​

Some of the questions imply that I have read some things on this on the web and have guesses as to the answers.

But I am here asking people who hopefully know more than I do about MB's

Though I am begining to think that I am in the wrong business. That I might be able to pay my mortgage if I learn how to reprogram ECU's and EIS's and .....

Start with what you can do first. (Key tests).​


And I get peved when I am told I need some 50K software hardware combination to reprogram some car computer.
I wrote the software to do that for tractors and skid steers and ....
It is not that complicated. The hard part is getting the secret knowledge needed.

And even if you can not get that. reprogramming most programmable chips is not all that hard either.
The hard part is knowing what to put in or take out.
See some replies above:
 
#21 ·
Based on the history (assuming you have good battery voltage at the battery terminals or charge points under the hood), I would do the following first:

1) check your car key. If you see the red LED blink when you press any key and stop blinking even if you keep the key pressed. this is an indication that the micro controller inside the chip is working (even though the remote function separate from the ignition function, they use the same controller.

2) Check the Infra-red light at the tip with a smart phone camera. When you press a key you should see it blinking through at the camera screen.

3) Have you changed batteries in the key ? If you did, you can remove the printed circuit board, after removing the white plastic "lock" at the back edge of the PCB. Once you remove it, you can measure the resistance between the tracks along the coil at the tip. If open, you have one or more tracks cracked (common failure). If you read something like less thann 100 ohms you have connectivity at the tracks. A close visual inspection also can show you a crack (magnifier)

If cracked you can fix the crack with some careful soldering and put everything together and try.

You can have up to 24 keys I think (3 *8).

If the problem is in the EIS your best bet is to have a complete set from a donor car at ebay (ECU, EIS, key and the ESL) making sure that it comes from the same same car (part number should match). That should not cost a lot.
 
#22 ·
The Car Battery is brand spanking new. The key problem happened as part of the process of replacing the battery.
The old one only manage 11.7v - almost certainly a dead cell. It has been off and on bitterly cold here and weak batteries sometimes freeze and that is not good for them. Regardless th eold batter was 10years old so it was time to replace it.
It better be able to put out 12.5v.

But I will check it.
 
#24 · (Edited)
Wait a second . . .

. . . we attempted to start the car the message panel said "take key"
Key insertion microswitch in the EIS stuck? Didn't we just have a member have that problem? Lemme see if I can find a picture or thread . . . well, this is not the thread I was thinking of, but it does show good pics of the microswitch I'm thinking of:



Click on that picture to go to the thread. While that's a W220 EIS and ours doesn't look quite like that (they're not interchangeable) I think I recall that our actual key sense microswitch is similar.

AFAIK, the two MCUs can be swapped from your existing EIS to another one, merely the usual fine SMT swap skill needed, the tutorials I've seen don't show using even a hot rework station. I've got a couple of spare JY EIS units sitting in my garage, just to someday play with; you can have one if you think you want to try a swap. You'll have to transfer those two MCUs, but it sounds like you have that skillset.
 
#25 ·
The key insertion is recognized, however the barrel lock is not released so you cannot turn the key.

If the key is inserted , and you hear whirring from the steering column, and the column lock is released, this would indicate the key is recognized by the EIS (so that it requested an ESL unlock). Once the unlock ack message is received from the ESL to the EIS, the EIS will unlock the barrel lock so the key would turn. If it does not, then this is an EIS mechanical / electrical problem, not an authorization issue.

So if the steering columns is not whirring, the chances are the key is not recognized (or the ESL is bad, which is possible but less likely).
 
#26 ·
"Take Key"

When do you see this message? For example, if an incorrect key is inserted?

(I have spare keys that don't fit my car . . . running outside to try one in my car . . . )

OK, now I see that the "Take Key" message is displayed with working and non-working keys. Got it, sorry for the tangent.
 
#27 ·
Thank you!

I will start with you suggestions regarding the key.
I highly doubt the car has gone through 24 keys so if that is correct that is worth knowing.

Wouldn't that mean one way of "testing" the key would be to try to add another key ?
Is the add key procedure for a W210 here somewhere ?

I presume that any donor key that works is acceptable for parts swapping,
But that adding a key - requires a special key.
Are these only avialable through MB ?
 
#29 ·
You should see some answers to your questions in the link below. Your car has DAS3

Mercedes-Benz Forum - View Single Post - Help!! with 2000 C 230 Smartkey replacement

I assume whoever ordered the lost keys replacements went through the procedures with MB dealer(s) paperwork., and if declared lost, those keys will no be active, so you will have only one active key (if 7 had been declared as lost).

If you contact the dealer they should order you a replacement key, as they have a centralized database for all transactions regarding key mamagement (assuming that the car has its original or MB replaced EIS), no something that was bought from a Junk Yard or Ebay.
 
#30 ·
As I said, you open the door, get in the car, and insert the key without turning. If you hear a whirring sound from the steering column, that means the key is recognized. If not, the key is not recognized or the Key lock is not handshaking with the EIS.

"take key" indicates that the EIS is powered, and your door is opened (as if you are getting out of the car and it reminds you, It does not mean the key is valid. It just says that there is a key inserted and take it out.

So if the EIS is powered, and you have a good battery (12.5V you mentioned), it would be key or the EIS issue (with less likelihood of ESL).

Does the key lock / unlock the doors remotely ?
 
#31 ·
I thought I should provide the end resolution to all of this.

I pulled the EIS from the car and sent it as well as the one key I had to
The Master Locksmith <info@themasterlocksmith.com>
They determined that the key was defective, repaired it, programmed the key/EIS for an additional key - now I have a spare.

Mail between the US and UK took a while - but the car had been out of service for a long time.

On return, I reconnected the EIS and both the new and old key worked.

I still had some subsequent problems.
For some reason the EIS lock - that prevents removing or turning the key no longer works properly.
I had to disconnect that cable to be able to start the car reliably and remove the key reliably.
I also had to tear abort the center console as aparently spilled coffee had wreaked havoc with the "neutral switch"
and I was frequently finding I could not start the car at random.

At this point the dash board and center console are half re-assembled,
but the car is working reliably.
 
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