MBWorld.org Forums - c63 odometer delays when engine starts

hello guys ! i just bought a c63 2009 with 178k km...everything was alright untill i went to a garage to change brakes and some small issues but everythibg was mechanical nothing related to electrical issues....when i went back i stoped the car beside a shop, locked it with open windows, then when i got back tried to unlock the car with the key it didnt work so i opened it from insied it started ab alarm sound i tried to start the engine but it didnt start, few seconds kater then it turned on and directly i went to the garage , he told me there was an IC not welded well so it worked fine....the problem is that sinxe that happen, whenever i start the engine the rpm needle in the odometer shows after 1 or 2 seconds from starting the car....pleaseeee I need to know ehatvis the problem???? and is it something dangeeous????