LEMON Manuals: Even more car manuals for everyone
Home >> Smart >> 2015 >> Fortwo Electric Drive, 2D Convertible >> Repair and Diagnosis >> External Pages >> Different car >> Section 35 (Central Locking System - 212 Chassis) >> Basic Knowledge >> Keyless Go, function - GF80.61-P-0005FL

Keyless Go, function - GF80.61-P-0005FL

WARNING: This page does not describe the selected car, but rather 33 other vehicles, including the 2016 Mercedes-Benz E63 S AMG, 2016 Mercedes-Benz E400, 2016 Mercedes-Benz E350, 2016 Mercedes-Benz E300, and 2016 Mercedes-Benz E250. However, it is still accessible from the selected car via links, so may be relevant.

MODEL 212 with CODE 889 (Keyless Go) 

Fig 1: Keyless Go Block Diagram
G10242332Courtesy of MERCEDES-BENZ USA

KEYLESS-GO, general 

The KEYLESS-GO comfort function allows keyless locking/unlocking of the vehicle as well as starting and switching off the engine without inserting the transmitter key into the electronic ignition lock control unit. It is sufficient to just carry the transmitter key.

IMPORTANT Operation of the central locking (CL) via the transmitter key remains possible parallel to the KEYLESS-GO functions.

IMPORTANT MODEL 212

with CODE 551 (Anti-theft alarm system)

with CODE 889 (Keyless Go)

The antitheft alarm (ATA [EDW]) behaves in the same way as if the car were unlocked and locked with the transmitter key.

The KEYLESS-GO system includes the following partial functions:

Function sequence for position finding of transmitter key 

To reliably or securely realize the locking/unlocking and engine start/stop function, it is necessary to determine the position of and authorize the transmitter key.

The following illustration indicates the components with the KEYLESS-GO control unit uses to detect the area around the vehicle or in the vehicle where the transmitter key is located.

Shown on model 212.0 

Fig 2: Overview Of Keyless-Go Control Unit - Shown On Model 212.0
G10242333Courtesy of MERCEDES-BENZ USA

The position is determined when a capacitive sensor in a KEYLESS-GO door handle or the trunk lid/liftgate external operation switch is actuated.

The KEYLESS-GO control unit directly reads in the signals from the capacitive sensors.

The rear SAM control units directly reads in the status of the trunk lid external operation or liftgate external operation switch and transmits it to the KEYLESS-GO control unit via the interior CAN.

Then the KEYLESS-GO control unit transmits coded requests to the transmitter key via the KEYLESS-GO antennas. The transmitter key decodes these requests and transmits coded requests correspondingly when it is located in area A, B, C or D.

The KEYLESS-GO control unit receives the responses from the transmitter key via the rear window antenna and FM 1, AM, ZV and KEYLESS-GO antenna amplifiers and evaluates them. If the evaluation is positive, the KEYLESS-GO control unit authorizes the transmitter key.

IMPORTANT In the event of unusual load conditions of the vehicle (load with high volume of metal), the fields transmitted via the antennas by the KEYLESS-GO control unit are reflected or absorbed to a high degree, which can possibly lead to erroneous detection. The maximum overlap between the detected inside and outside area (measured at the side window) is approx. s = 10 cm depending on the vehicle contour. This means, the transmitter key is definitely located inside or outside the vehicle above s = 10 cm. At less than 10 cm (gray zone), the transmitter key position detection may be faulty.

Additional function requirements for locking/unlocking 

IMPORTANT The electronic ignition lock control unit sends the circuit 15 status over the interior CAN to the KEYLESS-GO control unit.

Function sequence for locking/unlocking: 

The locking/unlocking function allows the vehicle to be opened and closed via the CL.

The following control elements are available:

To lock and unlock:

To unlock:

IMPORTANT The sensor units in the KEYLESS-GO door handles are switched off when circuit 15 is switched on. Activation takes place when circuit 15 is switched off and a door is opened. In order to preserve the life of the on-board electrical system battery (G1), the capacitive sensor on vehicles up to 31.5.10 is switched off in the KEYLESS-GO door handles after t = 72 h. On vehicles up to 31.5.10 after switching off, the vehicle can no longer be unlocked by mere intervention (detected by the capacitive sensor) in the KEYLESS-GO door handle. The KEYLESS GO door handle must be pulled. On vehicles as of 01.06.2010 the capacitive sensors are set to the power saving mode. I.e., the "Checking cycle time" for the capacitive sensors is increased and the power consumption is reduced.

The locking/unlocking function comprises the following partial functions:

Function sequence for preadjustment of unlocking mode 

Basically the following types of unlocking are differentiated:

Simultaneously pressing the lock/unlock buttons on the transmitter key for t = 5 s, switches the system between two types of unlocking. The LED on the transmitter key comes on to confirm this change.

Function sequence for locking/unlocking vehicle: 

Unlocking possibilities: 

Option for opening trunk lid:

Locking possibilities: 

Unlocking (example of global unlocking at the left front door):

When you reach into the left front KEYLESS-GO door handle, the capacitive sensor in the door handle recognizes this. The KEYLESS-GO control unit reads in the signal from the capacitive sensor and transmits a wake-up signal to the transmitter key via the left rear door KEYLESS-GO antenna.

IMPORTANT In other vehicle areas, the KEYLESS-GO trunk antenna, the right rear door KEYLESS-GO antenna or interior compartment KEYLESS-GO antenna transmits a wake-up signal to the transmitter key.

The transmitter key sends its access authorization code and its position via the rear window antenna and the FM 1, AM, CL [ZV] and KEYLESS-GO antenna amplifier to the KEYLESS-GO control unit. The KEYLESS-GO control transmits this data to the electronic ignition lock control unit via the interior CAN.

If the access authorization is valid, the electronic ignition switch control unit transmits the request "Unlock" via the interior CAN to the following control units:

The left rear door control unit unlocks the left front door lock via the left front doors central locking motor.

The right front door control unit unlocks the right front door lock via the left front door central locking motor.

The left rear door control unit unlocks the left rear door lock via the left rear door central locking motor.

The right rear door control unit unlocks the right rear door lock via the right rear door central locking motor.

The opening request to unlock the trunk lid or liftgate is enabled by the rear SAM control unit via the external operation switch.

On vehicles with code (885) Extended theft protection, the following components are actuated additionally:

The left front door control unit actuates the left front door additional door lock actuator motor.

The right front door control unit actuates the right front door additional door lock actuator motor.

The left rear door control unit directly actuates the left rear door additional door lock actuator motor.

The right rear door control unit directly actuates the right rear door additional door lock actuator motor.

Function sequence for acoustic locking feedback (as of 01.06.2010) 

The acoustic locking feedback function is selected via the control level in the instrument cluster. The instrument cluster transmits the corresponding status via interior CAN to the front SAM control unit. When function is activated, the front SAM control unit momentarily actuates the horns via the horn relay after successful locking or unlocking. For this purpose the electronic ignition lock control unit transmits the "Lock" or "Unlock" request to the front SAM control unit via the interior CAN.

Number of acoustic signals:

IMPORTANT If a door, the trunk lid or the liftgate is still opened when locking, no acoustic locking feedback takes place.

Function sequence for optical locking feedback 

After the CL is locked or unlocked successfully, a visual feedback is output via the turn signals.

The electronic ignition lock transmits the request "Lock" or "Unlock" to the front SAM control unit via the interior CAN. The front SAM control unit then actuates the hazard warning flashing function by means of outputting the flasher frequency over the interior CAN. All turn signals are actuated synchronously on the vehicle. One flashing cycle is output when unlocking. Three flashing cycles are output when locking. If a door is still open when locking, there is no visual feedback. The front door control units send the status of the corresponding front door to the electronic ignition lock control unit via interior CAN. The rear door control unit transmit the status of the corresponding rear door via the interior CAN.

IMPORTANT Detailed information on performing the hazard warning flasher function is included in the function description "Exterior lights, function" in the partial function "Turn signal light actuation, function".

Function sequence for unlocking and opening trunk lid or liftgate 

External operation switch:

When the external operation switch is pressed, the trunk lid or the liftgate are unlocked and opened. The rear SAM control units directly reads in the status of the external operation switch and transmits it to the KEYLESS-GO control unit via the interior CAN.

With code 871 (Sensor system for trunk lid opening/closing)

The function is actuated by foot motion ("kick motion") in the rear of the rear switching module below the bumper. The rear switching module directly reads in the signals from rear switching module sensors, evaluates them and transmits the corresponding request to the KEYLESS-GO control unit via the KEYLESS-GO LIN.

In both cases the KEYLESS-GO control unit then actuates the trunk KEYLESS-GO antenna, which transmits a wakeup signal to the transmitter key. The transmitter key sends its access authorization code and its position via the rear window antenna and the FM 1, AM, CL [ZV] and KEYLESS-GO antenna amplifier to the KEYLESS-GO control unit. The KEYLESS-GO control unit transmits the access authorization code via the interior CAN to the electronic ignition lock control unit. If the access authorization code is valid, the electronic ignition switch control unit then transmits the request "Unlock trunk lid or liftgate" to the rear SAM control unit via the interior CAN. The rear SAM control unit then actuates the trunk lid central locking motor (model 212.0) or liftgate central locking motor (model 212.2) to unlock the rotary tumbler.

IMPORTANT MODEL 212.2 with CODE 889 (Keyless Go)

Further information on automatic opening and closing the liftgate, is given in the partial function liftgate control unit.

Function sequence for closing trunk lid or liftgate and locking vehicle (model 212.0/1 with code (881) Remote trunk closing (RTC)) or liftgate (model 212.2) 

Trunk lid control button (model 212.0/1):

The rear SAM control unit directly reads in the status of the trunk lid control button and transmits it to the trunk lid control unit via the interior CAN, which starts closing the trunk lid.

Liftgate control button (model 212.2):

The rear SAM control unit directly reads in the status of the liftgate control button and transmits it to the liftgate control unit via the interior CAN, which starts closing the liftgate.

IMPORTANT Further information for automatic closing the liftgate or the trunk lid is given in the partial function liftgate control function (model 212.2) and trunk lid control function (model 212.0/1).

After closing the trunk lid or liftgate, the vehicle is locked with the central locking unless a valid transmitter key is located in the sensing range.

Additional function requirements for engine start/stop 

Function sequence for engine start/stop 

The function engine start/stop enables to engine to be started and switched off via the KEYLESS-GO start/stop button.

The engine start/stop function encompasses the following subfunctions:

Function sequence for interrogation of transmitter key 

The KEYLESS-GO control unit starts the check for an authorized transmitter key under the following conditions:

IMPORTANT The trunk lid or liftgate are evaluated as if they were a door.

IMPORTANT If during the interrogation of the transmitter key no transmitter key is detected in the vehicle interior, the instrument cluster outputs the message "Key not detected" in red text. In this case it is possible to switch off the engine, however, it cannot be started.

Additional function requirements for starting engine 

Function sequence for starting engine 

The engine is started when the KEYLESS-GO start/stop button is pressed. The electronic ignition lock control unit directly reads in this request and transmits the status "Start/stop button pressed" via the interior CAN to the KEYLESS-GO control unit. The KEYLESS-GO control unit evaluates this and transmits wake-up and location-finding signals to the transmitter key via the center console KEYLESS-GO antenna.

The transmitter key sends its access authorization code and its position via the rear window antenna and the FM 1, AM, CL [ZV] and KEYLESS-GO antenna amplifier to the KEYLESS-GO control unit. The KEYLESS-GO control unit transmits the access authorization code via the interior CAN to the electronic ignition lock control unit.

If the access authorization code is valid, the electronic ignition lock control unit transmits the circuit status 50 via the chassis CAN (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013) to the CDI control unit (on diesel engine) or ME-SFI control unit (on gasoline engine) and the engine is started.

The electronic selector lever module control unit (on transmission 722.6) or intelligent servo module for DIRECT SELECT (on transmission 722.9) or fully integrated transmission control unit (with transmission 725) transmits the status "Transmission selector lever in position P or N" via drive CAN, CDI control unit or ME-SFI control unit (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013), front SAM control unit and interior CAN to the KEYLESS-GO control unit.

When the service brake is operated, the brake lights switch switches the applied voltage through to the Electronic Stability Program control unit or to the regenerative braking system control unit. The electronic ignition lock stability program control or regenerative braking system control unit transmits the status of the service brake via the chassis CAN (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013) to the electronic ignition lock control unit.

Function sequence for display of fault messages 

If no valid transmitter key is recognized in the interior compartment during a start attempt, the message "Key not recognized" appears in the multifunction display on the instrument cluster. The start attempt is interrupted. The status of the circuit remains unchanged.

If, during a start attempt, the selector lever is not in position "P" or "N", a warning tone sounds. A corresponding note is therefore displayed on the multifunction display. For this purpose, the KEYLESS-GO control unit sends corresponding requests over the interior CAN to the instrument cluster.

Function sequence for circuit switching 

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

Function sequence for shutting off engine 

When the KEYLESS-GO start/stop button is pressed when the engine is running, the engine is requested to shut down. The electronic ignition lock control unit detects when the KEYLESS-GO start/stop button is pressed and transmits the status "Start/stop button pressed" to the KEYLESS-GO control unit via the interior CAN. The KEYLESS-GO control unit evaluates it and transmits the request "Switch off engine" via the interior CAN to the electronic ignition lock control unit, which passes on the request via the chassis CAN (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013) to the CDI control unit or to the ME-SFI control unit.

The CDI control unit or ME-SFI control unit then shuts off the engine depending on the vehicle speed.

Switching off the engine depends on the vehicle speed:

The instrument cluster sends the vehicle speed to the KEYLESS-GO control unit via the interior CAN.

IMPORTANT MODEL 212 with TRANSMISSION 722, 724, 725

with CODE 460 (Canada version)

with CODE 889 (Keyless Go)

MODEL 212 with TRANSMISSION 722, 724, 725

with CODE 494 (US version)

with CODE 889 (Keyless Go)

The engine is not switched off as long as transmission position "P" is engaged.

  Electrical function diagram for Keyless Go MODEL 212 with CODE 889 (Keyless Go) PE80.61-P-2050-97DAA 
  Overview of system components for theft protection and locking   GF80.00-P-9999FL 
scientia non olet · About LEMON Manuals