Hello.

I just bought 1999 slk230 a few days ago from a private seller.

The vehicle came with following keys.

Key A.
Remote with a key. Remote is broken. Replaced battery, can't get battery check light on. The metal key lock/unlock door and started fine til this afternoon.

Key B
Brand new remote with a key that the sellar told me that he bought from the dealer for this vehicle. Remote flashes red light when I push any buttom. Remote does not work. The metal key does not even open door nor start the engine. The seller told me to take it to dealer when I bought the vehicle.

Now I was just trying the brand new remote making work by fllowing instruction on the manual. Then, I can't start the engine by the metal key A. It still lock and unlock the door, but turns over just once and give me "Start Error" message on the odometer. Remote on key B still does not lock/unlock the door.

I just bought it on Saturday and I have not even be able to register my car at DMV. Does anyone know how to remove this "Start error"?

Please help me!!!

Thanks.

 

You don’t have a key programmed with the correct RFID. You will need to visit a dealer. With VIN and proof of ownership you can get a key. There is no other way.

I assume you’re in the USA; you didn’t say.

New cars come with two key/remote fobs and one flat key.

The USA SLK key fob consists of three separate components integrated into one package: a mechanical ignition key, a radio frequency (RF) transmitter, and a radio frequency identification (RFID) module.

The flat key consists of the combination of a mechanical key and an RFID imbedded in the plastic head.

The mechanical key is of course cut to match the mechanical lock on the ignition switch. It can be removed and replaced from the fob, so it is possible to alter this portion of the fob to match another vehicle.

The RF transmitter is powered by a battery and activated by the buttons on the remote to lock and unlock the doors and, if so equipped, arm and disarm the alarm. It works much like a garage door opener and uses a rolling code technology. This technology requires that the transmitter and receiver be in synchronization. The receiver must know the next code(s) to expect from the transmitter. Since the owner’s manual describes how to synchronize transmitters, it is reasonable to assume that the RF transmitter portion of a fob bought off eBay could be synchronized to your car (although I have never tried it). Note that when you synchronize it is actually the receiver (the car) that is programmed to or learns the transmitter, not vice versa.

The RFID is a small passive device, meaning it has no power supply of its own. Its main components are a coil, a capacitor, and a chip. These components are typically sealed in glass, cylindrical in shape, and quite small – like a grain of rice. In fact they can be made small enough to be imbedded under the skin of animals and even humans. Surrounding the SLK ignition switch is a coil. When you turn your key to start your car, the Dive Authorization System (DAS) sends a high-frequency burst to the ignition switch coil. This induces a current in the nearby RFID coil which charges the capacitor. The capacitor in turn powers the chip for a short time. The chip sends back a coded pulse which is now received by the ignition switch coil and relayed back to the DAS. If the DAS likes it, it tells the ECU to start the engine. If not, it says START ERROR.

The RFID can be programmed once and only once with a code to broadcast. It can be programmed using a special transmitter. It is programmed with a code, or number, than matches the DAS in your car – in effect, your VIN. Since it cannot be reprogrammed, it is not possible to use one from a different car to start your car.

If you buy a fob off eBay, it will have the RFID already programmed to another car. It can’t be changed.

Disclaimer: I don’t know any of this for 100% certain, but it’s what I have pieced together from various bits of information.

 

I bought 2 set of remote with a key from a dealer.
Now they work fine. Thank you foy your info. Paid over $250 though.