Fuel and ignition system 9112 · Control unit programming 2470 Functions of VarioCam

Fuel and ignition system 9112 Control unit programming 2470 Functions of VarioCam Plus in ME 7.8 Motronic engine management Additional functions system ? Control unit type: This checks, if the data status of the Both individual systems of the VarioCam control unit is current or not current. Plus (valve timing and valve stroke) are ? Saving document field in working pro- actuated by the Motronic engine manage- tocol: ment system All completed Motronic control unit Control of the VarioCam Plus requires as programming is shown with vehicle input variables, the engine speed, acceler a- identification number, service number, tor pedal position, engine oil temperature, part number, date and program status. coolant temperature and gear recognition (Tiptronic and manual transmission). The OBD (EOBD) driver's torque and power requirements are compared with the control unit maps and World-wide via the on-board diagnosis sys- then a decision is made as to whether the tem (OBD – USA) or Europe on-board diag- VarioCam Plus system has to be switched. nosis system (EOBD – Europe/RoW) the The switch-over point is then calculated driver is informed by an appropriate warn- from these values. ing (Check Engine lamp) in the instrument cluster. The functions are adapted to the Elements of the following functions run different world-wide legal regulations. simultaneously during a switch-over proc- ess ? Throttle valve position (E-gas) ? Mixture formation ? Ignition ? Actuation of solenoid hydraulic valve to adjust valve timing ? Actuation of solenoid hydraulic valve for valve stroke 2_19_02 ? A permanently lit "Check Engine" lamp indicates an emission-related fault ? A flashing "Check Engine" lamp indi- cates a combustion fault which may damage the catalytic converter 2 - 6 Service Information 2002