The Sprinter and the Mercedes-Benz Metris have a fully multiplexed electronic system, networked with several CAN bus systems.
The programmable special module (PSM) provides the interface between the vehicle and auxiliary electronic systems and creates a host of possibilities.
The programmable special module (PSM) is an optional adjustable electronic module that is the only approved analog and digital gateway into the vehicle's electronic system.
The PSM was developed specifically to provide customers, upfitters and, fleets hardware and software access to individual types of CAN bus data for electrical installations and full functional integration of their products.
It is the only way to access the CAN bus data and thus it can be used to read specific vehicle information and control specific vehicle functions.
The Sprinter or Metris vehicle information from the CAN bus can be evaluated and routed onto the body manufacturer CAN bus or multifunction inputs and outputs when adapting aftermarket electronic equipment or upfitting.
The control unit and the corresponding functions differ between the Sprinter and Metris model. Some described functions are only available on the specific vehicle model type.
The mode of operation for the engine function is only available in the PSM of the Sprinter.
In the Sprinter and the Mercedes-Benz Metris the programmable special module is installed in the left seat base.
The modes of operation for the PSM module are different in the Sprinter and the Metris. Single described functions are only available on the specific model.
To avoid electromagnetic interference, fault codes or false signals to the electronic control units; according to the Body & Equipment Guideline, never cut into or interfere with the CAN wiring harness.
Depending on the equipped factory options codes, the PSM can be customized using up to 30 inputs or outputs.
Additionally, an Auxiliary CAN Module can be connected to the PSM to extend connectivity.
The PSM can decrease or eliminate additional wiring or relay logic due to straightforward integration into on-board power supply.
The internal PLC (programmable logic controller) is a module with freely programmable and freely interconnect able function blocks for creating any signal links that may be required
The PSM software can include logic combinations (AND, OR, NOR, XNOR etc.) of a variant of signals.
PSM signals can be processed internally in Timer, Counter and Hysteresis Blocks or Threshold Switches to trigger specified Output signals or Input functions. The PSM in the Metris has also an Arithmetic logic unit with following function:
calculating blocks; filters; integrators/differentiators; comparators; characteristics; non-volatile memory options; freely definable constants
A customized software program must be uploaded to the PSM via a Diagnostic Tool, by authorized Mercedes-Benz Canada dealer or Upfitter.
The customized PSM software dataset can be transferred to other same-type vehicles in the fleet.
The PSM Support is the authorized entity to program and provide non-standard PSM software. The aforementioned group will develop and validate the software after a program request has been submitted.
A feasibility study of all the customer desired functions is done in dialog with the Upfitter in order to address and meet all the needs.