So this is where I am now. Have a switch, but don't know how to proceed from here. I did go to my local repair shop, but they told me they couldn't recode it, and I'd have to go to the dealer. The dealer wants $930 to do the job, but first they want to do a diagnostic for $200. So this could get expensive.
At Australian ECU Repair, we only specialize in Mercedes-Benz ECU repairs and re-manufacturing of customers 'own unit'. All our repairs include a complete rebuild and re-engineering to eliminate common factory faults, enabling us to supply every ECU with up to 1 year unlimited KM warranty*
W211 ecu repair
The Sensotronic Brake Control unit is a unique unit. Mercedes-Benz were one of the first vehicle manufacturers to employ a brake-by-wire system on a car (W211, R230). Called sensotronic (SBC), the system no longer relies on the driver to produce hydraulic pressure. The brake pedal is connected to the computer (ECU) by wire (brake-by-wire).
This ECU is a very common fault for the Mercedes A Class, it causes the engine management light to come on and fault code for the Air Mass/Flow Meter to be stored in the ECU's memory. This fault can cause the engine to run rough and idle poorly.
Mercedes E Class W211/R230 SBC Repair CODE C249F – Sensotronic Brake Control (SBC) If you own a Mercedes E Class W211 or SL R320 and have a brake error, then you must replace the SBC unit which can be very expensive from the dealer.