Weird start/non start issue security system? - PeachParts Mercedes-Benz Forum

chaosrob · #1 05-07-2022, 07:54 AM

Short time 1999 e300 owner here and was needing some input from long term owners and or people well versed with the platform.

Recently my car has begun not wanting to start when I first get in it and insert the key. The lights all come on but the glow plug light doesn't light up and it will not engage the starter when I turn the key. If I lock and unlock the door then insert the key it will start. I thought this may be a low battery in the fob so I changed it to no avail. I thought it might be the transponder in the fob so I grabbed the other key and it still does it. Then I thought it could be because I leave the key in the car (not in the ignition) since it is garaged and moved the key away from the car when sitting, no dice.

The problem is intermittent and always rectifies itself after the lock unlock procedure but I am afraid it is just going to give up the ghost completely at some point and leave me stranded. Can someone possibly point me in the right direction of what the issue may be? TIA

jay_bob · #2 05-08-2022, 09:12 AM

This vehicle has the first generation DAS (Drive Authorization System). I've had experience with this when I had my E300.

Do you have the all black plastic key (panic button in the rear end) or a replacement (with chrome sides and the panic button on the piece that inserts into the dash)?

The on board diagnostics does keep track of what is holding it out from starting, but this requires the dealer level Xentry system to properly diagnose.

Several forum members (including myself) have clones of the system for diagnosis. If you edit your profile and put where you're located it will help other members know where you are.

One thing to be careful of is that the dealer will happily sell you a new key for around $400, matched to your VIN. The problem is that you have the first generation system and the latest type chrome keys (that were in use up through about 2016 or so) are not compatible with the first generation system.

If you just bought the car and the key is football shaped with chrome sides the seller may have gotten a replacement key from the dealer before selling it. The problem is that the new keys only work intermittently in my experience.

When I had this problem the dealer said they could replace the electronics in the dash but it would cost more than the car is worth.

But there is another option, there are locksmiths out there who specialize in these computer chip keys. They have a tool that pulls the security codes off the chip in the ignition switch (take out the switch module, disassemble the module, unsolder the security chip and put it in a reader to get the codes, then put it all back together) and use that data to make replacement keys (using NOS or surplus old style keys).

chaosrob · #3 05-09-2022, 06:55 PM

Thank you very kindly for your reply.

Here are the keys I received with the vehicle

Quote:

Originally Posted by jay_bob

This vehicle has the first generation DAS (Drive Authorization System). I've had experience with this when I had my E300.

Do you have the all black plastic key (panic button in the rear end) or a replacement (with chrome sides and the panic button on the piece that inserts into the dash)?

The on board diagnostics does keep track of what is holding it out from starting, but this requires the dealer level Xentry system to properly diagnose.

Several forum members (including myself) have clones of the system for diagnosis. If you edit your profile and put where you're located it will help other members know where you are.

One thing to be careful of is that the dealer will happily sell you a new key for around $400, matched to your VIN. The problem is that you have the first generation system and the latest type chrome keys (that were in use up through about 2016 or so) are not compatible with the first generation system.

If you just bought the car and the key is football shaped with chrome sides the seller may have gotten a replacement key from the dealer before selling it. The problem is that the new keys only work intermittently in my experience.

When I had this problem the dealer said they could replace the electronics in the dash but it would cost more than the car is worth.

But there is another option, there are locksmiths out there who specialize in these computer chip keys. They have a tool that pulls the security codes off the chip in the ignition switch (take out the switch module, disassemble the module, unsolder the security chip and put it in a reader to get the codes, then put it all back together) and use that data to make replacement keys (using NOS or surplus old style keys).

jay_bob · #4 05-09-2022, 11:39 PM

The key towards your fingertips is the original key. Looks like for 99 they moved the panic button onto the business end of the key (my 98 had it in the butt end of the key).

The key in your palm is a later generation smart key. I can tell because the first generation keys that have the chrome sides, were built with a single membrane plastic piece (similar to your older key) for the lock, unlock, and trunk. The later version chrome keys have the buttons as discrete pieces of plastic that actually travel up and down.

When I ordered a replacement key for my 98 (in 2019) they sold me a key like that in your palm that worked intermittently. I also had the original black key for the car still and it worked fine. The person who sold me the car had gotten another key from the dealer in approximately 2011-2012 and it was the chrome with membrane style buttons and it worked fine. Unfortunately that 2011 era key got lost.

Now a little deep in the weeds theory on how these keys work. There are actually 3 things going on inside the key.

The first thing is the lock/unlock/trunk function, this uses radio waves to a receiver in the vehicle to handle the lock/unlock/pop the trunk functions via the PSE pump under the back seat. The W210 has pneumatic operated locks similar to the earlier generation vehicles dating back to the 1960s, they couldn't quite let that technology go even in the 1990s, after just about everyone else had been using solenoids by then and for quite a while before.

The second thing is an infrared emitter and receiver. This has 2 functions, first if you aim the remote at the receiver windows in the driver and passenger door handles, and hold down the unlock button, it will open all the windows and sunroof in addition to unlocking the car. Holding down the lock button closes all the windows and sunroof and locks the car. The receiver windows in the 210s have gotten roasted by UV from the sun by now and chances are this will only work if you are in the shade, have a fresh set of batteries in the key, and hold it directly over the door receiver window. The second thing the IR is used for is to help with authentication of the key. There is an IR transmitter/receiver also in the key slot in the ignition switch that also communicates with the key when it is inserted. I believe what happens here is this is re-synchronizing the rolling code for the lock/unlock function, since even in the 90s people were stealing cars by spoofing the remote unlock code.

The third thing the the key does is that there is a passive RFID chip in the nose of the key. I believe it is the same part as the grain of rice sized microchip they put in your dog or cat in case it gets lost. This is activated by a wire ring around the key slot, the code from the microchip is compared to the stored numbers in the security chip in the ignition switch, and only if they match will the drive authorization happy dance commence.

There is a whole chain of events that happens between key insertion and a successful start. Having access to Xentry is essential to see where things are breaking down. I see now you're in the STL area, don't know any forum members offhand who live near you with a Xentry unfortunately.

What happens if you use the original black key?

chaosrob · #5 05-10-2022, 05:47 PM

Thank you again.

It still does it intermittently, maybe I will try replacing the battery in that one as well.

It seems to work more frequently

Quote:

Originally Posted by jay_bob

The key towards your fingertips is the original key. Looks like for 99 they moved the panic button onto the business end of the key (my 98 had it in the butt end of the key).

The key in your palm is a later generation smart key. I can tell because the first generation keys that have the chrome sides, were built with a single membrane plastic piece (similar to your older key) for the lock, unlock, and trunk. The later version chrome keys have the buttons as discrete pieces of plastic that actually travel up and down.

When I ordered a replacement key for my 98 (in 2019) they sold me a key like that in your palm that worked intermittently. I also had the original black key for the car still and it worked fine. The person who sold me the car had gotten another key from the dealer in approximately 2011-2012 and it was the chrome with membrane style buttons and it worked fine. Unfortunately that 2011 era key got lost.

Now a little deep in the weeds theory on how these keys work. There are actually 3 things going on inside the key.

The first thing is the lock/unlock/trunk function, this uses radio waves to a receiver in the vehicle to handle the lock/unlock/pop the trunk functions via the PSE pump under the back seat. The W210 has pneumatic operated locks similar to the earlier generation vehicles dating back to the 1960s, they couldn't quite let that technology go even in the 1990s, after just about everyone else had been using solenoids by then and for quite a while before.

The second thing is an infrared emitter and receiver. This has 2 functions, first if you aim the remote at the receiver windows in the driver and passenger door handles, and hold down the unlock button, it will open all the windows and sunroof in addition to unlocking the car. Holding down the lock button closes all the windows and sunroof and locks the car. The receiver windows in the 210s have gotten roasted by UV from the sun by now and chances are this will only work if you are in the shade, have a fresh set of batteries in the key, and hold it directly over the door receiver window. The second thing the IR is used for is to help with authentication of the key. There is an IR transmitter/receiver also in the key slot in the ignition switch that also communicates with the key when it is inserted. I believe what happens here is this is re-synchronizing the rolling code for the lock/unlock function, since even in the 90s people were stealing cars by spoofing the remote unlock code.

The third thing the the key does is that there is a passive RFID chip in the nose of the key. I believe it is the same part as the grain of rice sized microchip they put in your dog or cat in case it gets lost. This is activated by a wire ring around the key slot, the code from the microchip is compared to the stored numbers in the security chip in the ignition switch, and only if they match will the drive authorization happy dance commence.

There is a whole chain of events that happens between key insertion and a successful start. Having access to Xentry is essential to see where things are breaking down. I see now you're in the STL area, don't know any forum members offhand who live near you with a Xentry unfortunately.

What happens if you use the original black key?