Engine start/stop, function - GF80.61-P-3012GZ

MODEL 164 with CODE (889) Keyless Go up to Model Year 2008

Fig 1: EIS Control Unit Communication Diagram

Courtesy of MERCEDES-BENZ USA

Shown on model 164.1

Function

The engine can be started or switched off by pressing the start/stop button.

Start engine

Function requirements

The transmitter key is located in the vehicle interior
Selector lever is in position "P" or "N"
Service brake applied

Function sequence

When the start/stop button is pressed, the KEYLESS-GO system (KG) is woken up and the signal "Start engine" is transmitted to the EIS control unit

Parallel to this, the KEYLESS-GO control unit searches for and wakes up a valid transmitter key via the KEYLESS-GO cockpit antenna and the KEYLESS-GO interior antenna. The position of the transmitter key is transmitted to the KEYLESS-GO control unit via the roof antenna module. The KEYLESS-GO control unit transmits the access authorization code to the EIS control unit via CAN B.

If the access authorization is valid, circuit 15R and circuit 15 are switched on, if not already switched off, and the engine is started.

If the start/stop button is pressed, without the foot brake being operated, circuit 15R is switched on. Repeated actuation actuates circuit 15. Repeated pressing switches off the circuit 15. If the driver door is closed, circuit 15C remains active for approx. 30 minutes.

Errors occurring are output by the instrument cluster 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 interrupted (circuit 15R and circuit 15 remain off).

If the selector lever is not in position "P" when an attempt is made to start, the instrument cluster indicates "Selector lever to P or N".

Additional circuit switching operations are given in the table below.

Switch off engine

Function requirement

Selector lever is in position "P" or "N"

The position of the transmitter key is not checked.

Function sequence

The engine can be switched off any time by pressing the start/stop button the EIS control unit.

While driving, the start/stop button must be actuated for at least 3 s to shut off the engine.

Parallel to this, the selector lever position is checked.

The engine is switched off through circuit 15. When the driver door is closed, circuit 15R remains active and the steering is unlocked.

If the selector lever is not in position "P" when the engine is switched off, and audible warning signal sounds and the following text appears in the instrument cluster: "Selector lever to P or N".

If the selector lever is not in position "P" or "N" when an attempt is made to switch the engine off and the transmitter key is recognized, the text "Selector lever to P or N" appears in the instrument cluster.

If a door is opened when the engine is running and the vehicle is standing still, the EIS control unit checks the key when restarting If a transmitter key is not recognized in the interior compartment of the vehicle, the instrument cluster indicates "Key not recognized" The engine remains on, however, the car should be taken to a workshop without delay. If the transmitter key is available, the vehicle should be restarted with the transmitter key.

If the functions described are activated via the start/stop button and a valid transmitter key is inserted in the EIS control unit, the transmitter key is given priority if the selector lever is in position "P". If running, the engine is switched off.

If, after starting the engine, the transmitter key can no longer be located in the vehicle interior (system error or transmitter key not present), the instrument cluster outputs a warning message for approx. 5 s.

This is repeated every 5 km. After traveling > 20 km, a continuous warning message is output and an intermittent gong sounds.

Vehicles up to 31.5.07:

Next time the vehicle stops (v = 0 km/h) the engine is automatically switched off.

Vehicles as of 1.6.07:

These warning messages are maintained until the driver switches off the engine (no automatic engine switch-off).

In this case, it is not possible to start the engine on either version.

Actuation with start/stop button Initial status: Circuit 15R Off, Circuit 15 Off and Engine Off	Status after actuating start/stop button Prerequisite: Selector lever in position "P" or "N"	Status after actuating start/stop button Preconditions: Driver door is opened after operating pushbutton Service brake not actuated when operating pushbutton.	Status after actuating start/stop button Preconditions: Driver door remains closed after operating pushbutton, Service brake not actuated when operating pushbutton.
1st actuation	Circuit 15 On, engine is started Requirement: Service brake operated	Circuit 15R On	Circuit 15R On
2nd actuation	Circuit 15R On, engine is switched off Requirement: Doors closed	Circuit 15 On	Circuit 15 On
3rd actuation	Circuit 15 On, engine is started Requirement: Service brake operated	Circuit 15 Off Circuit 15R Off Circuit 15C Off	Circuit 15 Off Circuit 15R Off Circuit 15C On

Transmitter key, component description	A8/1	GF80.57-P-6010GZ
Keyless-Go control unit, component description	N69/5	GF80.61-P-4200GZ
Electronic ignition switch control unit (EIS), component description	N73	GF80.57-P-6000GZ