GF80.61-P-3012GM Engine Start/Stop, Function

GF80.61-P-3012GM Engine Start/stop, Function
- with CODE (889) Keyless Go


General function requirements
The engine start/stop function allows to start and stop the engine.

The engine start/stop function comprises the following subfunctions.
^ Function sequence for starting engine
^ Function sequence for circuit switching
^ Function sequence for stopping engine

Additional function requirements for starting engine
^ Transmission is in position "P" or "N"
(signal from intelligent servo module for DIRECT SELECT (A80))
^ Brake pedal actuated (signal from ESP control unit (N47-5))

The signals are routed by the central gateway control unit N93) from the engine compartment CAN to the interior CAN and thereby transmitted to KEYLESS-GO control unit (N69/5).

Function sequence for starting engine
Actuation of the KEYLESS-GO start/stop button (S2/3) is read in by the EIS control unit (N73). It transmits the signal to the KEYLESS GO control unit via interior CAN.

The KEYLESS-GO control unit then transmits the wake-up and locating signals to the transmitter key via the:
- Keyless Go cockpit antenna (A2/60)
- interior Keyless Go antenna (A2/61)

The transmitter key transmits its access authorization code and its position to the roof antenna module (A2/93), which relays the information to the KEYLESS GO control unit. The access authorization code is transmitted to the EIS control unit via the interior CAN.
If the access authorization is valid, c. 15R and c. 15 are switched on by the EIS control unit and the engine is started by the ME-SFI control unit (N3/10) (with gasoline engine) or CD control unit (N3/9) (with diesel engine).

Possible error messages in instrument cluster (A1):
- If a transmitter key is not recognized in the interior compartment when starting, the instrument cluster indicates "Key not recognized" and the start attempt is inhibited. The status of the circuit remains unchanged.
- If the DIRECT SELECT gear selector switch is not in position "P" or "N" when the engine is started, a chime sounds and a corresponding text appears in the instrument cluster.

Each time the vehicle is started or if a door is opened with the engine running, the EIS control unit requests the KEYLESS GO control unit to check the transmitter key.
If a transmitter key is not recognized in the passenger compartment, the instrument cluster indicates: "Key not recognized".

Function sequence for circuit switching
If the brake pedal is not depressed when the KEYLESS-GO start/ stop button is actuated, only circuit 15R is switched on. Repeated actuation activates circuit 15. Further repeated actuation switches circuit 15R and circuit 15 off. If the driver door is closed, circuit 15C remains active for t = 30 min.

Function sequence for stopping engine
The signal "Stop engine" is transmitted to the EIS control unit by pressing the KEYLESS-GO start/stop button and then the engine is switched off via circuit 15. If the driver door is closed, circuit 15R remains active for t = 30 min.

Switching off engine depending on vehicle speed:
- Speed below v = 3 km/h: Switch-off occurs immediately
- Speed above v = 3 km/h: Switch off occurs only after pressing KEYLESS GO start/stop button for an extended period (t > 3 s).