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Functional Scope Of Engine, PSM, Function - GF54.21-D-3007TSH

Model 447, 448 

with code ED5 (Parameterisable special module) 

with code XM7 (MOPF II) 

Speed limit 

Model 907, 910 

with code ED5 (Parameterisable special module) 

with code XJ4 (Modification year G4-I) 

Speed limit 

Speed limit (GB) 

The parameterizable special module (PSM) control unit (N26/16) enables functions in the CDI control unit (N3/28, N3/31, N3/33, N3/40, N3/47) or ME-SFI [ME] control unit (N3/34, N3/36) to be influenced. The speed limit parameterizable function module has been implemented for this purpose.

IMPORTANT The speed limit function and the ECO start/stop PLUS function are only possible with diesel engines.

Generally, when retrofitting special equipment, additional control units such as the electronic ignition lock (EZS) control unit (N73/8) (model 907/910) or electronic ignition lock (EZS) control unit (N73/8) (model 447/448) must be recoded to activate the function. Please observe the information in the diagnostic system in this context.

Speed limit function 

It is possible to switch on each of two parameterizable vehicle speed limits via the vehicle speed limit function.

Function module GB 1 (speed limit 1) 

G16501221Courtesy of MERCEDES-BENZ USA

Function module GB2 (Speed limit 2) 

G16501222Courtesy of MERCEDES-BENZ USA

Parameters for function of first speed sensor 

Request of first speed sensor via an input 

Request for activation of the first speed sensor via an input of the parameterizable special module (PSM) control unit (N26/16).

Parameterization possibilities:

Request for first vehicle speed setting from body manufacturer CAN (CAN ABH) 

Example: Actuation of the step plate switch triggers activation of the vehicle speed limit setting.

Parameterization possibilities:

Parameters for function of second speed sensor 

Request of second speed sensor via an input 

Request for activation of the second speed sensor via an input of the parameterizable special module (PSM) control unit (N26/16).

Parameterization possibilities:

Request for second vehicle speed setting from body manufacturer CAN (CAN ABH) 

Example: Actuation of the step plate switch triggers activation of the vehicle speed limit setting

Parameterization possibilities:

Maximum speed 

The respective maximum speeds are set via the parameter "First maximum speed [km/h]" or "Second maximum speed [km/h]" in the properties of the speed sensor. The speed sensor module is activated or deactivated via another parameter in the properties of the speed sensor.

IMPORTANT The parameterizable special module (PSM) control unit (N26/16) transmits only one maximum speed and only one activation status to the CDI control unit (N3/28, N3/31, N3/33, N3/40, N3/47) or ME-SFI [ME] control unit (N3/34, N3/36) via the body manufacturer CAN (CAN ABH). If the two parameterized maximum speeds are different and both are activated simultaneously, then the lower maximum speed applies. There is no lower limit for the value for the speed limit.

For the speed limit to take effect, the speed of the vehicle must be lower than the parameterized maximum speed once. This functionality allows, for example, an overtaking maneuver to be completed even if the vehicle speed limit was activated in the meantime.

"Engine start/stop" function 

The PSM control unit enables functions in the CDI control unit (N3/28, N3/31, N3/33, N3/40, N3/47) or ME-SFI [ME] control unit (N3/34, N3/36) to be influenced. The engine start/stop parameterizable function module which ensures correct operation of the parameterizable special module (PSM) control unit (N26/16) has been implemented for this purpose.

The "Engine start/stop" function can be used to start and stop the engine via the parameterizable special module (PSM) control unit (N26/16).

"Engine start" function 

The "Engine start" function requires the following input conditions before the engine start signal can be output:

With the "Engine start" function, the following input conditions can be parameterized for the internal function enablement:

IMPORTANT The "Engine start" and "Engine stop" functions are also possible if working speed control is active. Please note: If, following an engine stop, the working speed control function is deactivated, an external engine start is no longer possible. An ignition change is required to reset the "Engine start" and "Engine stop" functions.

If these conditions are met, output of the engine start signal to the interior CAN (CAN B) can be activated via the internal input "Request for engine start function".

It is also possible to determine whether the input conditions for executing the engine start are checked only at the time of activation or during the entire engine start attempt.

If a running engine is detected by the parameterizable special module (PSM) control unit (N26/16), the engine start signal is canceled.

If the engine does not start despite a request from the PSM, the engine start signal is reset after the timeout period (6 s) and fault B182F00 is stored in the fault memory. The engine start can then be activated again.

IMPORTANT The "Engine start" function via the parameterizable special module (PSM) control unit (N26/16) is only possible if the engine was switched off beforehand via the "Engine stop" function via the PSM control unit.

The internal inputs of the module can be parameterized via menu item "Special functions → Engine start and engine stop, input".

Engine start request via an input of parameterizable special module (PSM) control unit (N26/16) 

Request for function "Engine start" via an input 

IMPORTANT If an input of the parameterizable special module (PSM) control unit (N26/16) is used for the "Engine start" function, the "Switch/Pushbutton" parameter must be set to "Switch" at the input, irrespective of whether a switch or push button is used. Malfunctions can otherwise occur.

Parameterization possibilities:

Request for function "Engine start" via body manufacturer CAN (CAN ABH) 

Engine start request via body manufacturer CAN (CAN ABH).

Parameterization possibilities:

Condition for engine start, selector lever in position "N", with transmission 722.9 

IMPORTANT The availability of the signal depends on the vehicle equipment.

Activation input (bit signal) as condition for engine start.

Parameterization possibilities:

Requirement for engine start: Signal "Parking brake" via an input 

Activation input (bit signal) as condition for engine start. A signal from an additional parking brake installed in the vehicle or an additional parking brake indicator switch can be used here.

Parameterization possibilities:

Request for function "Engine start prevention" via an input 

Engine start prevention via an input of the parameterizable special module (PSM) control unit (N26/16). Engine start prevention is evaluated on an inverted basis.

Parameterization possibilities:

IMPORTANT This internal input can be used to prevent an external engine start via the module "Engine start and engine stop", even if all other conditions for an engine start are fulfilled. In order to prevent an engine start in general, e.g. via the ignition lock, it is necessary to parameterize the internal input "Engine start NOT PERMISSIBLE" via the module "Interfaces → Interior CAN, input".

Request for function "Engine start prevention" via body manufacturer CAN (CAN ABH) 

Engine start prevention via the body manufacturer CAN (CAN ABH) is evaluated on an inverted basis.

Parameterization possibilities:

IMPORTANT This internal input can be used to prevent an external engine start via the module "Engine start and engine stop", even if all other conditions for an engine start are fulfilled. In order to prevent an engine start in general, e.g. via the ignition lock, it is necessary to parameterize the internal input "Engine start NOT PERMISSIBLE" via the module "Interfaces→ Interior CAN, input". The module can be parameterized via the menu item "Special functions → Engine start and engine stop, properties".

Requirement for engine start: POWER TAKE-OFF SWITCHED ON 

Parameterization possibilities:

Requirement for engine start: Clutch 

Parameterization possibilities:

Requirements for engine start: Parking brake 

Parameterization possibilities:

Signals from the "Engine start" function that are stored in the signal pool 

"Engine start" signal 

This bit signal is the source of the engine start request transmitted via the interior CAN (CAN B). It is set by the function module for engine start.

This signal is set when the inputs of the function module for engine start are valid and one of the engine start requests (input, body manufacturer CAN (CAN ABH)) is active.

Function module for engine start 

G16501223Courtesy of MERCEDES-BENZ USA

"Engine stop" function 

The "Engine stop" function requires the following input conditions before the engine stop signal can be output:

If these conditions are met, output of the engine stop signal can be activated with the internal input "Request or engine stop function".

If a stationary engine is detected by the parameterizable special module (PSM) control unit (N26/16), the engine stop signal is canceled.

If the engine does not stop despite a request from the parameterizable special module (PSM) control unit (N26/16), the engine stop signal is reset after the parameterized timeout period and fault "B183000" is stored in the fault memory. The engine stop can then be activated again.

Function module for engine stop 

G16501224Courtesy of MERCEDES-BENZ USA

Request for "Engine stop" function via an input 

Engine stop request via an input of the parameterizable special module (PSM) control unit (N26/16).

Parameterization possibilities:

IMPORTANT If an input is used for the "Engine stop" function, the "Switch/Pushbutton" parameter must be set to "Switch" at the input, irrespective of whether a switch or pushbutton is used. Malfunctions can otherwise occur.

Request for "Engine stop" function via body manufacturer CAN (CAN ABH) 

Engine stop request via body manufacturer CAN (CAN ABH).

Parameterization possibilities:

Signals of "Engine stop" function that are stored in the signal pool 

"Engine stop" signal 

This bit signal is the source of the engine stop request sent via the interior CAN (CAN B). It is set by the function module for engine stop.

This signal is set when the inputs of the function module for engine stop are valid and one of the engine stop requests (input, body manufacturer CAN (CAN ABH)) is active.

Engine run-on 

Vehicles with code MW1 (Engine run-on control (MWS)) have an engine run-on function. The function is implemented in the drivetrain control unit (N127). The parameterizable special module (PSM) control unit (N26/16) only reads in the switch for the "Engine run-on" function and actuates the indicator lamp of the switch.

IMPORTANT After replacing the parameterizable special module (PSM) control unit (N26/16 Ser5i) in a repair case, SCN coding (online coding using the software calibration number) must be performed on series production vehicles with the diagnostic device.

Electric step (only for model 907/910) 

It is possible to actuate up to two electric steps independently of each other using the "Electric step" function module in the PSM. The "Electric step" function module is divided into two sub-modules "Step 1" and "Step 2" accordingly. Relays connected to the outputs of the parameterizable special module (PSM) control unit (N26/16) are required to actuate the steps.

G16501225Courtesy of MERCEDES-BENZ USA

Shown with code T57 (Electric step for right load compartment sliding door) and code T58 (Electric step for left load compartment sliding door) 

IMPORTANT If only one step is installed, it is always connected to the pins of "Step 1". This condition applies irrespective of the installation location of the step. If two steps are installed (e.g. with code T57 (Electric step for right load compartment sliding door) and with code T58 (Electric step for left load compartment sliding door)), then the right step is connected to the pins of "Step 1" and the left step to the pins of "Step 2".

The figure legend and the block diagram contain the maximum equipment configuration and apply to vehicles in which step 1 and 2 are installed. In the case of vehicles with only one step installed, only the figure legend entries for step 1 apply.

Signal settings 

The "Signal settings" menu can be used to assign signal IDs to the internal inputs of the step 1 or 2 function module. In some cases, it is also possible to parameterize the internal input, e.g. in order to invert the assigned signal.

Inputs 1 and 7 in the "Electric step" function module are intended for monitoring of the external relay circuit of step 1 or 2. These inputs should not be used for other functions if the step function module is activated. The same applies to inputs 09 and 10; they are reserved for object recognition.

Pushbutton 

The digital inputs of the parameterizable special module (PSM) control unit (N26/16) can be used for reading in a pushbutton; however, in principle, any signal ID from the signal pool can be assigned to the switch internal input.

Parameterization possibilities:

Limit switch "Step RETRACTED" 

Generally, the signal ID of a digital input of the parameterizable special module (PSM) control unit (N26/16) is assigned to the limit switch internal input "Step RETRACTED".

Parameterization possibilities:

Limit switch "Step EXTENDED" 

Generally, the signal ID of a digital input of the parameterizable special module (PSM) control unit (N26/16) is assigned to the limit switch internal input "Step EXTENDED".

Parameterization possibilities:

Property parameterization 

Parameterization of the basic properties of the electric step function module is possible via the menu item "Property parameterization".

Step 1 or 2 

Step 1 or 2 can be deactivated with this parameter.

Step 1 or 2 is activated if the associated installation location is set in the parameter, e.g. "Right sliding door". The selection of the respective installation location has an effect on the function block that evaluates the signals with respect to door status (see block diagram ("OR logic block")).

Example:

If "Right sliding door" is parameterized, the step function module only evaluates the signal 0x11C3 (DrRLtch_SD_R_Open).

Step 1 or 2, object recognition input for contact strip 

The circuit for object recognition can be connected to analog inputs 09 or 10. These inputs must be parameterized as a 560 ohm rocker switch.

Step 1 or 2, actuation: Input for relay monitoring 

This parameter can be used to set whether input 01 or 07 should be used for monitoring of the external relay circuit.

Steps, general: VEHICLE DRIVING/NOT DRIVING 

A hysteresis can be set using the two parameters to allow the system to clearly determine whether or not the vehicle is moving.

Example:

The parameterization provides the following hysteresis:

Hysteresis shown 

G16501226Courtesy of MERCEDES-BENZ USA
  Overview of system components for parameterizable special module (PSM)   GF54.21-D-9998TSB
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