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451 Electronics

1715 Views 8 Replies 8 Participants Last post by  jimvw57
I know that just about every part on the Fortwo can be repaired or replaced. But the big problem to a Fortwo owner would be troubleshooting electronic problems. I'm talking about the types of things that would require the Mercedes Star Computer system to troubleshoot or flash certain components of the electronics.

I seem to remember here on the forum it being discussed that if the SAM were to totally fail on your vehicle that you just couldn't purchase a used part and replace it on your's because of the serial number or mileage stored in it would be wrong. Can they be switched out and the vehicle still operate? I would guess that maybe replacing the Sam from another vehicle you would also have to have the matching ignition keys because the new Sam wouldn't allow you to start the car due to lockout.

Also can the ECU be traded from another vehicle since it holds firmware also? I would guess that other electronic devices like transmission controller etc,...could feasibly be replaced from another car without a Star Computer?

DCO
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I know that just about every part on the Fortwo can be repaired or replaced. But the big problem to a Fortwo owner would be troubleshooting electronic problems. I'm talking about the types of things that would require the Mercedes Star Computer system to troubleshoot or flash certain components of the electronics.

I seem to remember here on the forum it being discussed that if the SAM were to totally fail on your vehicle that you just couldn't purchase a used part and replace it on your's because of the serial number or mileage stored in it would be wrong. Can they be switched out and the vehicle still operate? I would guess that maybe replacing the Sam from another vehicle you would also have to have the matching ignition keys because the new Sam wouldn't allow you to start the car due to lockout.

Also can the ECU be traded from another vehicle since it holds firmware also? I would guess that other electronic devices like transmission controller etc,...could feasibly be replaced from another car without a Star Computer?

DCO[factory.
I know on my 451 there is a wiring harness for fog lights. If I were to install factory fog lights and use a factory button set for the dash, I still have to take the car to a smart center or MB dealer so they can hook up their STAR computer at around $100 to tell the " SAM" to allow factory fog lights to work.
If I were worried:

Buy a replacement SAM from the dealer and have them program it.

Ask them to return your old one as a spare.

Not sure but I think the mileage can be programmed...
Not too knowledgeable on the smart electronics, but I remember upgrading my PT Cruiser GT’s PCM to a mopar stage 1. This was a non canbus system but still had to send out the PCM to flash the vin number/skm number onto it (for keys to be recognized) and even had to go to dealership after to flash in some other things like pinion factors for speedo/odo to work.

I’m sure it’s doable on the smart but feel it’s very likely to require dealership computers to flash pertinent info onto car unless you swap ECM, SAM, and Ignition/keys all together from a identically equipped parts car.


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IIRC, a SAM replacement unit has to be activated by a star machine, be it a MB dealership, independent, eBay unit, or otherwise.

As for just hot swapping the SAM, ECU, etc and ignoring wrong odos and such, I can't say. I don't recall anyone ever trying that.
I've got a spare SAM from a wrecked smart but I'm not willing to try exchanging it.
Hoping the day never comes that I need to try it!
If purchasing a used SAM be sure you match the options list so you have less risk of it not working, ie if you have fog lights make sure the wrecked one it comes from had fog lights. Someone with EPC can do this matching for you....
I am having an issue with my coolant fan turning on. I replaced with a new fan. Still no luck. I believe it's my SAM. I found a replacement with same numbers as mine. Replaced in the car tonight and won't start. I get the key symbol on the dash. The imobilizer is activating.

I guess and hope that my SAM can be programmed to my car to work and that solves my cooling fan issue.
As posted above, the replacement SAM needs to be encoded or matched to your car. Since the SAM runs everything, it needs to know the serial numbers to everything else like the dash, key switch, transmission computer, abs, etc. A job for someone with the computer and software required. SOS can do it, and of course the local MB dealer

S.O.S. Diagnostics S.O.S. Diagnostics
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