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Discussion Starter #21
person with smart car wont start, mine doing same thing did you ever figure it out, mine had a cup of water spill on the dash, right over the fuse box then quit
No I have never determined why may smart won;t start, I thought it was the SAM unit so I sent the SAM unit,ECU, instrument cluster and a key to SOS diagnaustics and they put my modules in there test car and everything worked fine. my ignition tests good, the imobilizer ring is good. I have narrowed the problem down to the CAN Bus I think.
The Smart cars are notorious for having leaking windshirlds, seems the windshield leaks and lets water get on the SAM unit and shorts it out or corrodes the conections and causes the SAM unit or connections to fail. In your case spilling a cup of water onto the SAM unit (fuse box) if the car quit immediately then the water probably shorted out the SAM unit. This is just my opinion as I am not a professional Smart mechanic.
 

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thank you for replying so fast, im sorry when I said it quit right away it did not it made it home the when tried to start again next day would no start. can you tell me what the CAN BUS is, thanks
 

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Discussion Starter #23
thank you for replying so fast, im sorry when I said it quit right away it did not it made it home the when tried to start again next day would no start. can you tell me what the CAN BUS is, thanks
CAN stands for central area networking, and bus is a group or cluster. an example of a bus would be your fuse bus. CAN was developed by Bosh and consists of 2 wires that connects all of the modules in your car such as the ECM, TCM, SAM, instrument cluster, ABS module and so on. Each module receives and transmts signals through these two wires. Each module has its own bianary code so no other module will get a code intended for the module the coded signal is intended for. Every module communicats with each other over these two wires. Each module receives a command from the SAM unit and responds back to the SAM unit. The 2 wires consist of a CAN high and a CAN low, the CAN is connected to the OBDII port and the CAN is what a code reader or scan tool communicates with when pluged into the OBDII port. Any module that malfunctions has the info stoed in the CAN BUS as to what the malfunction issue purtains to.
Since water was spilled on your SAM unit that would be the first place I would start to look for the problem, however you can not just plug another SAM unit in, it will not work because the SAM will need to be programed to your car which can only be done by a Mercedes Benz dealer or someone with a Star diag tool loaded with Mercede Benz software. If you took the SAM unit from a wrecked Smart and put it in your Smart it would not work without being programed to your Smart. The only way I know of to replace any of the parts without programming is to get the SAM unit, ECM, instrument cluster and a working key from another Smart and put all the modules in your car. this could get expensive but it will be expensive to take your Smart to MB dealer. Another option would be to contact SOS and send them your SAM unit, ECM, instrument cluster and a working key, They can test your modules in their test car, if they determine your SAM is bad they can provide you with a SAM unit and program it to your car. They do not need your car to do this, but they do not test the modules for free, I think with shipping I had to pay around $240.00 just to have them test my modules and then found that my modules were all ok. But at least I now that the problem is somewhere else.
It might also help if you would explain in exact detail what your smart does when you turn the ingnition on and what happens when you try to start it.
 
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