Overview
This document contains information on:
General
Function requirements
Function
General
To start the combustion engine, the powertrain control unit actuates the starter. During the starting procedure, the combustion engine control unit coordinates the injection sequence and firing order.
The start quantity control in the combustion engine control unit calculates the fuel quantity required to start the combustion engine.
Function requirements
Engine management ON (circuit 87M)
Engine not in operation
Drive authorization system 4 (DAS 4) start enable
Drive range P or N engaged (automatic or dual-clutch transmission)
Function
Due to the start position of the ignition key, the electronic ignition lock control unit transmits its status to the body/drivetrain signal acquisition and actuation module. If the combustion engine control unit detects engine running and the end of the starting procedure, the driver can regulate the engine speed via the accelerator pedal sensor.
Function schematics | |||
Function schematic for starting | Engine 608 in model 118, 177, 247 | ||
Engine 282 in model 118, 177, 247 | |||
Engine 654 in model 118, 167, 177, 247Engine 654 in model 213, 238, 257 as of model year 2021Engine 656 in model 167, 223 | |||
Engine 254, 264 in model 213, 238, 257 as of model year 2021Engine 256 in model 167Engine 256 in model 213, 238 as of model year 2021 | |||
Engine 176, 177 in model 167 | |||
Engine 139 in model 118, 177 | |||
Engine 256 in model 223 | |||
Engine 176, 177 in model 223 | |||
Engine 279 in model 223 | |||
Additional basic functions | |||
End of start, basic function | Engine all (CAR) | ||
Control units | |||
Combustion engine control unit, basic function | Engine all (CAR) | ||
Powertrain control unit, basic function | Engine all (CAR) | ||
Electronic ignition lock control unit, basic function | Engine all (CAR) | ||
Components | |||
Accelerator pedal sensor, basic function | Engine all (CAR) |