Functional Scope Of Engine, PSM, Function - GF54.21-D-3007PC
MODEL 906 with CODE ED5 (Parameterisable special module) with CODE XM0 (Facelift) Speed limit
MODEL 906 with CODE ED8 (Preinstallations electrical system, PSM) with CODE XM0 (Facelift) Speed limit
Engine functions
The PSM control unit provides the possibility of influencing functions in the control unit. The parameterizable function modules "Vehicle speed limit" and "Remote engine start/stop", which ensure correct operation of the control unit, have been implemented for this purpose.
The vehicle speed limit function and remote engine start/stop function are only possible on diesel engines.
When retrofitting special equipment (e.g. code M53 (Constant rpm control)), it is generally necessary to recode further control units, e.g. electronic ignition lock (EZS) or control unit (ECU), to activate the function. Please observe the information in the diagnostic system in this context.
Function of speed limit
It is possible to switch on each of two parameterizable vehicle speed limits via the vehicle speed limit function.
Remote engine start/stop function
With the remote engine start/stop function, the engine can be started and stopped via the PSM control unit.
The remote engine start/stop function is only possible if the working speed control function is active. If, following engine stop, the working speed control function is deactivated, engine start is no longer possible.
First vehicle speed setting
Second vehicle speed setting
Parameters for "Vehicle speed setting" function
Request for first vehicle speed setting from discrete input
Discrete request for activation of first vehicle speed setting.
| Any signal | Any signal can be used here. |
| Continuous low (signal ID 1000) | Function deactivated |
Request for first vehicle speed setting from Controller Area Network bus, class C (body manufacturer) (CAN-ABH)
Example: Actuation of the step plate switch triggers activation of the vehicle speed limit setting.
| Any signal from CAN-ABH | Any signal from the CAN-ABH can be used here. |
| Continuous low (signal ID 1000) | Function deactivated |
Parameters for "Vehicle speed setting" function
Request for second vehicle speed setting from discrete input
Discrete request for activation of second vehicle speed limit.
| Any signal | Any signal can be used here. |
| Continuous low (signal ID 1000) | Function deactivated |
Request for second vehicle speed setting from Controller Area Network bus, class C (body manufacturer) (CAN-ABH)
Example: Actuation of the step plate switch triggers activation of the vehicle speed limit setting
| Any signal from CAN-ABH | Any signal from the CAN-ABH can be used here. |
| Continuous low (signal ID 1000) | Function deactivated |
The PSM transmits only one maximum vehicle speed and one activation status to the engine control unit via the CAN bus. If the two parameterized maximum vehicle speeds are different and both maximum vehicle speeds are activated simultaneously, then the lower maximum vehicle speed applies. There is no lower limit for the value for the maximum vehicle speed limit.
| 57a | = | 60 km/h |
| 57b | = | 40 km/h |
| 192a | = | True |
| 192b | = | True |
Result (signals on CAN bus) = Vehicle speed limit activated, maximum speed = 40 km/h
For the vehicle 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.
Maximum speed
The respective maximum vehicle speeds are set via parameter "First maximum speed [km/h]" or "Second maximum speed [km/h]" in the properties of the vehicle speed setting. The vehicle speed setting module is activated or deactivated via another parameter in the properties of the vehicle speed setting.
Remote engine start/stop function
Function "Engine start"
The "Engine start" function requires the following input conditions before the engine start signal can be output:
- Engine start function module activated (module parameter).
- "Tml. 15 ON" and engine OFF
- Possibly further module parameters
With the "Engine start" function, the following input conditions can be parameterized for internal function enable:
- Parameterization of internal inputs via menu item "Special functions → Engine start and engine stop → Signals"
- Requirements for engine start: Signal 'Parking brake' via an input
- Requirements for engine start: Transmission neutral position
- Request for function "Engine start prevention" via an input
- Parameterization of module via menu item "Special functions → Engine start and engine stop → Properties"
- Function "Engine start"
- Requirement for engine start: Parking brake
- Requirement for engine start: Power take-off SWITCHED ON
- Requirement for engine start: Clutch
The "Engine stop" and "Engine start" 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/engine stop function.
If these conditions are fulfilled, it is possible to activate output of the engine start signal on the interior CAN via the internal inputs "Request for function "Engine start" via an input" or "Request for function "Engine start" via the body manufacturer CAN bus".
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 PSM control unit, 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 B150B is stored in the fault memory. The engine start can then be activated again.
The function "Engine start via PSM control unit" is only possible if the engine was switched off beforehand via the function "Engine stop" via the PSM control unit.
The internal inputs of the module can be parameterized via menu item "Special functions → Engine start and engine stop → Signals".
Engine run-on
Vehicles with special equipment code MW1 (Engine run-on circuit (MWS)) are equipped with an engine run-on function. The function is implemented with an additional module of the PSM.
Manual parameterization of the module, e.g. via expert coding, is not possible. After replacing the PSM control unit during a repair, SCN coding (online coding with Software Calibration Number) must be carried out with the diagnostic unit.
Request for function "Engine start" via an input
Discrete engine start request.
| Any signal | Any signal can be used here. |
| Continuous low (signal ID 1000) | Function deactivated |
When using a discrete input for the "Engine start" function, the parameter "switch/button" on the input must be set to "switch", irrespective of whether a switch or a button is used. Malfunctions can otherwise occur.
Request for function "Engine start" via body manufacturer CAN
Engine start request via CAN-ABH.
| Any signal from CAN-ABH | Any signal from the CAN-ABH can be used here. |
| Continuous low (signal ID 1000) | Function deactivated |
Condition for engine start, selector lever in position "N", with transmission 722.6
The availability of the signal depends on the vehicle equipment.
Activation input (bit signal) as condition for engine start.
| Selector lever in position "N" (signal ID 10F2) | Query of neutral position of gear selector lever for activation of engine start |
| Query DEACTIVATED (signal ID 300B). | The query of this condition is deactivated. |
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.
| Any signal | Any signal can be used here. |
| Query DEACTIVATED (signal ID 300B). | The query of this condition is deactivated. |
Request for function "Engine start prevention" via an input
Discrete engine start prevention is evaluated on an inverted basis.
| Any signal | Any signal can be used here. |
| Continuous low (signal ID 1000) | Function deactivated |
This internal input can be used to prevent an external engine start via 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 module "Interfaces → Interior CAN bus → Miscellaneous".
Request for function "Engine start prevention" via body manufacturer CAN
Engine start prevention via CAN-ABH is evaluated on an inverted basis.
| Any signal from CAN-ABH | Any signal from the CAN-ABH can be used here. |
| Continuous low (signal ID 1000) | Function deactivated |
This internal input can be used to prevent an external engine start via 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 module "Interfaces - Interior CAN bus - Miscellaneous".
The module can be parameterized via menu item "Special functions → Engine start and engine stop → Properties".
Requirement for engine start: POWER TAKE-OFF ENGAGED
| ACTIVATED |
| DEACTIVATED |
Requirement for engine start: Clutch
| DEACTIVATED |
| Clutch pedal OPERATED |
| Clutch pedal FULLY DEPRESSED |
Requirements for engine start: Parking brake
| ACTIVATED |
| DEACTIVATED |
Signals of the function engine start which are stored in the signal pool
Signal "Engine start"
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 "Engine start".
This signal is set when the inputs of the function module engine start are valid and one of the engine start requests (discrete, CAN-ABH) is active.
Description of engine start function module
Function "Engine stop"
The "Engine stop" function requires the following input conditions before the engine stop signal can be output:
- Engine stop function module activated (module parameter).
- "Tml. 15 ON" and engine running.
When these conditions are met, the output of the engine stop signal can be activated with the outputs "Engine stop discrete" or "Engine stop CAN-ABH".
If a stopped engine is detected by the PSM control unit, the engine stop signal is canceled.
If the engine does not stop despite a request from the PSM, the engine stop signal is reset after the timeout period (6 s) and fault B150C is stored in the fault memory. The engine stop can then be activated again.
Parameters for "Engine stop" function
Request for function "Engine stop" via an input
Discrete engine stop request.
| Any signal | Any signal can be used here. |
| Continuous low (signal ID 1000) | Function deactivated |
When using a discrete input for the "Engine stop" function, the parameter "switch/button" on the input must be set to "switch", irrespective of whether a switch or a button is used. Malfunctions can otherwise occur.
Request for function "Engine stop" via body manufacturer CAN bus
Engine stop request via CAN-ABH.
| Any signal from CAN-ABH | Any signal from the CAN-ABH can be used here. |
| Continuous low (signal ID 1000) | Function deactivated |
Signals of "Engine stop" function which are stored in the signal pool
Signal "Engine stop"
This bit signal is the source of the engine stop request transmitted via CAN B. It is set by the function module "Engine stop".
This signal is set when the inputs of the function module engine stop are valid and one of the engine stop requests (discrete, CAN-ABH) is active.
Electric step
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 the two sub-modules of Step 1 and Step 2 accordingly. Relays connected to the outputs of the PSM are required to actuate the steps.
If only one step is installed, this is always connected to the pins for "Step 1". This condition applies irrespective of the installation location of the step.
If two steps are installed (e.g. SA code T57 AND T58), then the right-hand step (T57) is connected to the pins for "Step 1" and the left-hand step (T58) to the pins for "Step 2".
The legend for the block diagram shows the maximum equipment and applies to a vehicle with step 1 and 2 installed. In the case of vehicles with only one step installed, the legend entries for step 1 apply.
Signal settings
Using the signal settings menu, signal IDs can be assigned to the internal inputs of the step 1/2 sub-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 and 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 obstacle detection.
Switches
The digital inputs of the PSM can be used for reading in a push button switch but, in principle, any signal ID from the signal pool can be assigned to the switch internal input.
| Any signal | Any signal can be used here. |
| Continuous low (signal ID 1000) | Function deactivated |
Limit switch "Step RETRACTED"
Generally, the signal ID of a digital input of the PSM is assigned to the limit switch internal input "Step RETRACTED".
| Any signal | Any signal can be used here. |
| Continuous low (signal ID 1000) | Function deactivated |
Limit switch "Step EXTENDED"
Generally, the signal ID of a digital input of the PSM is assigned to the limit switch internal input "Step EXTENDED".
| Any signal | Any signal can be used here. |
| Continuous low (signal ID 1000) | Function deactivated |
Property parameterization
Parameterization of the basic properties of the electric step function module is possible via the property parameterization menu item.
Step 1/2
The step can be deactivated with this parameter.
The step 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 which 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 signal #105F (Right front door OPEN).
Step 1/2, obstacle detection input for contact bar
The circuit for obstacle detection can be connected to analog input 09 or 10. These inputs must be parameterized as a 560 ohm rocker switch.
Step 1/2, 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:
- Steps, general: VEHICLE DRIVING [km/h] receives value 7.
- Steps, general: VEHICLE NOT DRIVING [km/h] receives value 5.
The parameterization provides the following hysteresis:
| Parameterizable special module (PSM) control unit component description | GF54.21-D-5005P |