SL-Class (R230) 2003 -- 2012: Discussion on the SL500, SL550, SL600

SL/R230: Suggestions to re-vive a keyless go system

Old Sep 20, 2019 | 05:45 PM
  #1  
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2003 SL55, 2004 E320 CDI Estate
Suggestions to re-vive a keyless go system

Hi all, I've recently bought an 03 SL55. It's in great condition and I'm planning some preventative maintenance in the next few weeks. It has keyless go from the factory but it's completely not working. When the button is pressed on either the doors or shifer there is nothing. The previous owner said it never worked and he never tried to fix it.

I've been looking for the fuse, the fuse locations don't seem to match the diagram I found online as the car is a euro right hand drive. However every 7.5 amp fuse I've pulled looks fine. I've tried disconnecting the battery but no difference, I'm going to look for the relay next and try swapping it with another one to see if that makes a difference. I don't have star (but plan to buy a chinese clone) but I do have the iCarsoft MBII reader. However it cannot see the keyless module at all.

I'm thinking either the keyless has been coded out of the car (due to faults I would assume) or that there is no power to the module. I remember reading somewhere if the system has multiple faults it just shuts down but might be remembering that wrongly. I would also assume if that was the case you could still connect to it from the MBII reader.

The only other electrical issues are the CD player auto changer is dead, and the radio reception is a bit poor. Not sure if this is relevant.

My key batteries are both new.

Any ideas are welcome. I'm considering buying a star clone but I'm somewhat confused as to exactly what to order.

Last edited by Rawhide; Sep 20, 2019 at 05:51 PM.
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Old Sep 20, 2019 | 06:05 PM
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2003 SL500
AFAIK, in 03 models keyless is operated by a wallet size key card, not by the key. If you have no card, I doubt that you'd be able to get system to work.
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Old Sep 20, 2019 | 06:34 PM
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Originally Posted by alk247
AFAIK, in 03 models keyless is operated by a wallet size key card, not by the key. If you have no card, I doubt that you'd be able to get system to work.
Hmm - my car is an 03. I contacted MB and they told me that they could create a new key for me (when I was doing some research) and said it was a key based system and not the card. They could be wrong and i can try again now I have the chassis number.

However surely that doesnt explain why I cannot connect to it, nor get an error message when I press any of the buttons?
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Old Sep 20, 2019 | 06:50 PM
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Originally Posted by Rawhide
Hi all, I've recently bought an 03 SL55. It's in great condition and I'm planning some preventative maintenance in the next few weeks. It has keyless go from the factory but it's completely not working. When the button is pressed on either the doors or shifer there is nothing. The previous owner said it never worked and he never tried to fix it.

I've been looking for the fuse, the fuse locations don't seem to match the diagram I found online as the car is a euro right hand drive. However every 7.5 amp fuse I've pulled looks fine. I've tried disconnecting the battery but no difference, I'm going to look for the relay next and try swapping it with another one to see if that makes a difference. I don't have star (but plan to buy a chinese clone) but I do have the iCarsoft MBII reader. However it cannot see the keyless module at all.

I'm thinking either the keyless has been coded out of the car (due to faults I would assume) or that there is no power to the module. I remember reading somewhere if the system has multiple faults it just shuts down but might be remembering that wrongly. I would also assume if that was the case you could still connect to it from the MBII reader.

The only other electrical issues are the CD player auto changer is dead, and the radio reception is a bit poor. Not sure if this is relevant.

My key batteries are both new.

Any ideas are welcome. I'm considering buying a star clone but I'm somewhat confused as to exactly what to order.
if you need a real SDconnect Xentry star install, contact me, that will avoid buying crap
I also posted a keyless go thread
https://mbworld.org/forums/cl-class-...onversion.html



PM me
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Old Sep 20, 2019 | 09:38 PM
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From: Kirkland, WA
2003 SL500
Originally Posted by Rawhide
Hmm - my car is an 03. I contacted MB and they told me that they could create a new key for me (when I was doing some research) and said it was a key based system and not the card. They could be wrong and i can try again now I have the chassis number.

However surely that doesnt explain why I cannot connect to it, nor get an error message when I press any of the buttons?
I only get an error message when I push button on the top of the gear shifter for keyless start.
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Old Sep 21, 2019 | 05:52 AM
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Originally Posted by alk247
I only get an error message when I push button on the top of the gear shifter for keyless start.
Thanks - thats what I remember from my e55. That surely means no power, disabled or coded off.
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Old Sep 23, 2019 | 02:21 PM
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Run your VIN through www.datamb.com and make sure keyless go was really an installed option. FWIW, I coded out keyless go on my car, but it still works.

Last edited by JettaRed; Nov 5, 2019 at 11:46 AM.
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Old Sep 23, 2019 | 02:32 PM
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Originally Posted by JettaRed
Run your VIN through www.datamb.com and make show keyless go was really an installed option. FWIW, I coded out keyless go on my car, but it still works.
if you coded it out properly it does not work anymore
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Old Sep 23, 2019 | 03:04 PM
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Originally Posted by JettaRed
Run your VIN through www.datamb.com and make show keyless go was really an installed option. FWIW, I coded out keyless go on my car, but it still works.
Thanks. Mb have confirmed it was factory fitted and as its a euro spec car it is likely the key type rather than card based.
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Old Sep 23, 2019 | 03:29 PM
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Originally Posted by Rawhide
Thanks. Mb have confirmed it was factory fitted and as its a euro spec car it is likely the key type rather than card based.
go in the trunk, lookup the part number of you keyless go module and you will not need to guess anymore
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Old Sep 24, 2019 | 06:30 AM
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Originally Posted by pmercury
go in the trunk, lookup the part number of you keyless go module and you will not need to guess anymore
I was taking the boot apart as you posted. I do have the newer style unit which is key based. It looks dry and pins are fine. I will check the fuses again as I found a blown 7.5 amp fuse behind the seat but didn't have a spare.

After that I will replace the module, then see if coding is required as a last resort.
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Old Nov 5, 2019 | 11:49 AM
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Originally Posted by pmercury
if you coded it out properly it does not work anymore
Then I probably didn’t do it properly. However, when I first start the car I get a “Keyless Go — take it to the Workshop” message (or something like that).
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Old Nov 5, 2019 | 01:01 PM
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of course you have to edit settings and variant codings with Xentry DAS
this is not plug and play
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Old Nov 5, 2019 | 01:10 PM
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Originally Posted by pmercury
of course you have to edit settings and variant codings with Xentry DAS
this is not plug and play
I did. I remember now the I was trying to disable the stupid “Don’t Forget Your Key” reminder chime because with push button start, the key is always in my pocket.

Never got rid of the chime, but I did add a Workshop warning message. 🤪 Seems to have no effect on the Keyless Go function.
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