System Operation
Smart Start
The PCM enables the starting process when a key
providing a valid code is read via the PATS. This
code is then verified in the GEM and compared
with the saved code. If this code is recognized as
correct, synchronization with other modules is
carried out. After successful synchronization, the
engine is cleared to start in the PCM. The PCM
connects earth to the starter relay, which then
connects power to the starter solenoid. As soon
as the engine reaches a certain speed, the PCM
disconnects the starter relay and so turns off the
starter. This protects the starter.
If the engine does not turn or turns only slowly, the
starting process is aborted by the PCM.
The starter is not activated if:
• the engine is running (i.e. the engine speed is
above a particular value),
• the PATS does not permit the engine to be
started,
• the clutch pedal is not operated (vehicles with
manual transmission),
• the gear selector level is not set to P or N
(vehicles with automatic transmission),
• the brake pedal is not operated (vehicles with
automatic transmission).
Emergency starting function
If the keyless vehicle system is unable to recognize
the passive key, the vehicle can be started via the
emergency starting function.