I initially posted this over in the SL55 forum (here), but it's likely to be useful to some SL500 members.
It has been discussed over the years, but I couldn't find a thorough, descriptive explanation that covered the process end-to-end, so I thought I'd post it for everyone's benefit.

I successfully upgraded my 2003 SL55 from Keyless Go with card to Keyless Go with Key (heh).

What you'll need:
1. An updated Keyless Go module, ideally from an '04 to '06 SL.
The part number is A2305451232. This is a direct swap. The KG module is *not* keyed/coded against VIN, so you *can* get a used one (I did).

2. A key to match this Keyless Go module.
The part number is A230 766 03 06 9999. Don't bother with eBay keys. Go to your favourite dealer, who hopefully has a parts guy who's willing to work with you.

Step 1: Replace the existing KG module with the updated one
<I should take some photos to describe this somewhat accurately. It's similar to swapping out taillights.>
Location is on driver side, closest to the quarter panel. Same height as tail light, behind the carpeting.

Step 2: Order the new key
When you talk to the parts team to order the new key, they may either not want to order it outright, try to get you an updated part (newer key) or simply say "it's not compatible" (which technically it isn't for your VIN, but you've upgraded your KG module to account for that).

You'll still need to do VIN verification. If the parts dept sends the order for that specific key, for that part number to Mercedes Ft Worth, you *will* get the right key.
Mine cost me ~$400 and took 2 business days to arrive.

Step 3: Register/sync the new key
When you first receive your new key, it won't even unlock the steering wheel.
Leave the key plugged in and you should see 'Computing data' on your instrument cluster.

After ~15-30 minutes this should update (all times are apparently dependent on age and mileage).
At this point you should be able to turn the key to ACC and on to IGN.
Leave the key in IGN. The "Computing data" screen should appear once more.

This step will take several hours to complete. On my car it took ~3.5 hours.
I highly recommend that you turn off the climate control, headlights and radio. And if you have one available, hook up a battery tender/maintainer/charger to your main battery.

After this step completes, take out the key and verify it works to start the car.
Now take out the key and press that 'GO' button!

Step 4: Have a cold one and celebrate your success

 

Very nice!

In terms of cars with the newer SmartKey KG system, there have been some recent threads where an extra key was ordered and it worked immediately for RCL and DAS, but not for KG. The solution in those cases was to add the key in SDS. My understanding is that what you describe - the "computing" operation - is how this should work so nee need for SDS.

I assume that the old cards no longer work after replacing the KG control module?

 

I agree!

Yeah, I was a little surprised it worked almost out of the box without me having to go into SDS. I don't know enough about Mercedes key management to be able to explain *why*. But I'm happy it does.

The car never came with any. But yeah, they would probably stop functioning as soon as you change the KG module.

 

DAS (Drive Authorization System) reads the code from the key and then decides if it's one of the 32 possible valid ones. In terms of KG, it does not validate the code - it just reads it and hands it off to the components that do, namely the EIS (Electronic Ignition Switch). The KG control unit uses its antennas to scan for key codes in the vicinity. It validates the key code and then passes that info onto the EIS which authorizes it. the KG control unit has to have the valid RFID codes of the keys programmed into it. If not, it won;t even pass the code off to the EIS.

Here's some docs on the whole thing:

Control unit for MY2002: http://benzbits.com/r230/KeylessGo2002.pdf
Control unit for MY2003+: http://benzbits.com/r230/KeylessGo2003.pdf
Key Programming MY2002: http://benzbits.com/r230/KeylessGoKeys2002.pdf
Key Programming MY2003+: http://benzbits.com/r230/KeylessGoKeys2003.pdf

Here's more info on DAS (the R230 uses DAS 3):

http://benzbits.com/DAS.pdf

It seems that the KG control module is thus user-programmable for new keys, whereas the EZS is not. Also, certain other components are "anti-theft" coded, such as the ECU, TCU (for 722.9), steering wheel lock and shifter module. These have to be SCN coded, which is basically writing the VIN to them, but that can only be done using SDS with a live connection to MBZ.

 

Excellent, that's giving me plenty to read. Thanks for sharing.

 

I want to say Thanks to ArrArr. I found the new module on ebay for 29.00 and installed it when it arrived. I ordered the new key using the part number you posted. I got the key today and followed the instructions. The first programming took 20 mins. Then I was then able to turn the key. I turned it to ign and let it sit while I took my shower and watched a little TV. (1 hour 30 mins). It worked like a charm. Thanks again

 

Happy to hear it. That's exactly why I posted this. Enjoy your Keyless Go!

 

In a way, it's too bad that they didn't continue to support the card with the new KG system. I hate carrying a wad of keys in my pocket. I'd much rather just have a card slipped into my billfold.

 

Hi!
Even this tread is bit old, i have to add that A2307660306 9999 is wrong for programmed to cars VIN key. 9999 on the end for keys means it is unprogrammed = EMPTY (is for any car and needs extra programming to the FBS). For to VIN programmed cars there are two available options with designated ES2 code on the end: one is Replacement key and second one is addition key. Addition key does not need waiting time with "Computing data" on cluster as stated above, it opens Ignition right away. Only replacement Key needs "Computing data" time.
Regards,

 

Hi!
Even this tread is bit old, i have to add that A2307660306 9999 is wrong for programmed to cars VIN key. 9999 on the end for keys means it is unprogrammed (is for any car and needs progremming to the FBS). For to VIN programmed cars there are two available options with desifnated ES2 code on the end: one is Replacement key and secon one is addition key. Addition key does not need waiting time with "Computing data" on cluster as stated above, it opens Ignition right away. Only replacement Key needs "Computing data" time.This deletes = replaces old key in chain and thats why it is "Computing data".
Regards,

 

Well after reading this I went and grabbed the spare key for my SL and wham no Keyless Go functionality. So when I bought my 09 SL back in end of November, they couldn't locate the 2nd key (black tab) and only gave me one key (grey tab). A little over a month later I went to pick up the key, the guy opened the bag, and the lock unlock trunk and ignition all worked, but I never tried the Keyless Go (I just figured it would work) since I never even use the Keyless Go usually.

So is it possible to program the key myself or I need someone with SDS? If so, I can probably get my indy to do it free of charge (the engine and transmission mounts need to be changed along with the TPMS inoperative issue needing to be fixed, just more issues from when I bought the car ) or should I bother going after the MBZ dealer I bought the car from to do it free of charge? I feel like since they went ahead and got me the second key as part of the deal it should've been properly programmed.

I did read the PDF above but kinda lost on where to begin if that can help me solve it.

EDIT: I also read somewhere about the difference of just adding a new key versus deleting an old key then adding a new one. I'd prefer if I could delete the "lost" key since it is somewhere out there still most likely.

 

Super Good info, exactly what I've been looking for!

 

Does replacement key remote work? If yes than you key is not for KeylessGo (from outside keys are same but inside=PCB are different for Non Keyless and Keyless Keys) and you can't just reprogram it like that (needs special equipment and knowledge) these keys.

 

DAS 3 allows for 24 possible key codes, arranged in 8 "tracks" with 3 "segments" each. Imagine a spreadsheet where the tracks are the columns and the segments are the rows. For each track (column) only one key can be active. So, you can have up to 8 active keys at one time. The car is delivered from the factory with two keys - both for segment (row) 1, tracks (columns) 1 and 2. Any "extra" keys ordered will be assigned to segment (row) 1 of the next unused track (column). If a key is lost, you can have the shop determine which track it was assigned to (by delivering all known keys) and they can then either disable that track, or order a "spare" key for the track, which will come coded for the next unused segment of that track. When used, that key will lock out the lower segment for the track, thus disabling the missing key. If keys have been issued for all three segments of a given track, then the entire track must be disabled (via SDS) and an "extra" key for a new, unused track should be ordered.

Discounting the use of hacking and EEPROM programming tools, the only way to get a key for your car is from MBZ corporate, through an authorized dealer. MBZ keeps up with all keys that have ever been issued for every vehicle, so they know which tracks and segments have been used. When an "extra" key is ordered, they know to issue a key for the next unused track, segment 1. When a "spare" key is ordered, its track must be indicated by the dealer, and then MBZ issues the key for that track, on the next unused segment.

Now, in terms of KeylessGo, when a key is ordered, there is a specific part number for one with KeylessGo (option code 889) or without. If the shop looks up the part in EPC by the VIN, it will show the correct part number. Even if the shop orders the wrong key, i am not sure MBZ corporate would issue it as they know what options the car has by VIN, and the VIN is required to order a key. So, it is very unlikely that you would get a non-KG key for a car equipped with KG.

Keys ordered from MBZ corporate come pre-programmed and there is no shop coding or programming needed. "Extra" keys are ready to use for RCL (remote locking) and DAS (drive authorization). "Spare" keys (i.e. replacements that will override a lost key in a track) require a "teach-in", but this can be done yourself. Insert the key into the EIS (don't turn on the ignition) and then wait for about 95 minutes. You will see a message like "Vehicle calculating" on the MFD. Once completed, switch on the ignition. If the key is removed before teach-in completes, it can be restarted by reinserting the key, but the time will double!

All KeylessGo keys, even "extra" keys, must go through the teach-in process.

 

 

Need this for my CL, I have tried to make the used card I bought work, but it won't program.

 

Replied to your PM, but replying here too so anyone who stumbles on this thread and has the same questions can see it:

By installing the newer Keyless Go module (part number A2305451232), you're merely enabling the car to operate on the same frequency as the newer Keyless Go keys.
The older Keyless Go module that you have now in your 2003, just like my 2003 SL55, operates on a different frequency for the Keyless Go card.

1. Replacing the Keyless Go module does not require reprogramming the key. So yes, your current keys should still work to start the car (except they won't be KGO keys).
2. No. The newer 'metal' key is not compatible with 2003 or 2004-2006 Keyless Go modules (it is not a KGO key either, most of the time).
3. Yes, but you will need to getA230 766 03 06 9999. This is a black key, full plastic, no metal/chrome. Your dealer should be able to order this, though it will give a warning that the key will be incompatible (but it expects you to still have the 2003 Keyless Go module). Go ahead and order it. They'll tell you it's at your own risk.
The key will come programmed from Ft Worth, TX (Mercedes' center where they program and ship out all keys).
After receiving the key, insert it, let the car runs its computations, when available, proceed to turn the key to IGN,. After this step completes, you should be able to start the car both manually and via Keyless Go.

For what it's worth; ever since posting this thread I have *only* used KGO and it has worked flawlessly for me.

 

Hi ArrArr,

Hope you can help, I read your post about upgrading the keys on your 2003 SL55, very interesting

I am currently having issues with the Keyless and Remote locking on my 2003 SL55.

Symptoms:

• Keyless Entry/Start (KG) NOT Working - 'Key Not Recognised' appears on dashboard
• Remote Locking (RF) NOT Working - Cannot Lock/Unlock car at any distance
• Infrared Locking (IR) is Working, I am able to Lock/Unlock the car if I point the key(s) directly at the IR sensor(s) on the door handles (Where Boot, Doors and Petrol Cap all lock/unlock), which means the PSE pump is working.

So far I have:

1. Replaced main battery in boot
2. Charged Battery under bonnet (Was more or less already fully charged)
3. Replaced batteries in both key fobs
4. Checked all fuses (With 12v light tester)
5. Tried a couple of steps to sync the keys (Not sure if any of them were correct)
6. Connected to STAR, where there was no errors shown, however the '750 CGW. N93 (Central Gateway, Control unit)' was shown as 'NOT PRESENT' ??? (Not sure if this is normal or not)
7. Disconnected both batteries (overnight) in the hope a shutdown of the system resolved it
8. Unplugged all SAN connectors (Located behind drivers seat) one by one, after disconnecting both batteries.
9. Tested all other electrics in the car and everything else works including the alarm
10. One thing I have noticed is when the roof is down, the boot/roof separator button doesn't work, this cant be linked?

The car is mostly kept garaged, so can't be caused by a water leek (Boot and inside car are bone dry).

Any suggestions?

 

 

This article was amazing! Thank you for the information!

Has anyone tried to go a step further and retrofit a shift lever with start button? Would that work with the newer module?

Thanks again for the great article and instructions!

 

I have got a question for you guys.
I bought my 2003 with NO key fobs, it only came with the key card , the dealer wants $1000 for a new key ( car in not in the USA) . I have brought an SDS with me but somehow it got bricked , it was a china version.
My question is if I buy a complete key set with ECU and other modules like this
https://www.ebay.com/itm/Engine-cont...UAAOSwEGBcNyJK
I assume they key in igntion will work as its supposed too , but what about the new key cards? Will they need to be programmed to my exisiting keyless go module through star? Or do i just plug everything up and go?

 

Yes, no programming is needed, but there may be some settings in the engine management controller to tweak for optimum engine performance -- or not.

 

Thanks for the rapid response! So with this new set up it should just be swap over the components and it should work both key in ignition and push start?
Someone mentioned to me that the TCM module and shifter will need to be reprogramed to the new EIS ... is this true? This includes a shifter married to the ecu provided so im thinking that inofrmation is wrong, it will be a true plug and play kit..

 

I don't believe that is correct. However, this eBay auction does not include the shifter. The electronic parts which must all belong to a common VIN are the engine management computer, the shifter, and the ignition switch.

 

Gotcha! that one was way expesnive as well., For $300 i got 2 key fobs , 1 KG card , ECU , EIS, and shifter , so I should be able to swap everything and be good to go since all modules will have a common vin and have been previously married. Thanks for your help!