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

MODEL 906 with CODE (ED5) Parameterizable special module (PSM) power take-off (PTO) 

MODEL 906 with CODE (ED8) Preinstallation for parameterizable special module (PSM) power take-off (PTO) Engine functions 

The PSM control unit provides the possibility of influencing functions in the engine control unit.

For this the parameterizable function module power take-off (PTO) has been implemented which ensures the correct operation of the engine control unit.

Function "PTO" 

The PTO function is used to control activation of the PTO on vehicles with PTO.

To prevent damage to the transmission, various conditions can be queried.

PTO 

G10887858Courtesy of MERCEDES-BENZ USA

Function "PTO" 

If required, the function module "PTO" can be used to connect/disconnect a device driven by the engine to/from the main transmission. In the process the PSM control unit actuates the power take-off solenoid valve which triggers the hydraulic activation of the PTO.

With the PTO, the following input conditions can be parameterized for internal function enable:

When these conditions are met, the actuation of the power take-off solenoid valve can be activated with the outputs of the PTO request discretely or via the controller Area Network bus Class C (body manufacturer) (CAN Body manufacturer).

Parameterization option "Overriding of unfulfilled switch-on conditions possible" 

If this option is set, an unfulfilled condition for the PTO can be overridden by resetting or setting the PTO request. This action generates a fault entry (9401, PSM control unit functionality "Power take-off - Driver has forced activation"). The condition that has been overridden is coded in the freeze frame variables of the fault entry. If this option is not set, the power take-off solenoid valve can only be actuated when all conditions are fulfilled and only when the PTO request is set.

Parameters for "PTO" function 

PTO request from discrete input 

Discrete request for activation of PTO. If an unfulfilled condition for the PTO is overridden, a fault entry (9401) is made. The freeze frame data of the fault indicates which input has been overridden. If an unfulfilled condition for activation of the PTO is detected when this input is actuated, an event entry (9405) is made. The freeze frame data for the event contains the information indicating which conditions are not yet fulfilled.

Parameterization possibilities:

Any signal

Any signal can be used here.

Permanent LOW (signal ID 1000)

Function deactivated

Power take-off request from CAN Body manufacturer 

Request via the CAN Body manufacturer for the activation of the PTO. The fault code (9401) with its freeze frame data is set in the same way as for the discrete request.

Parameterization possibilities:

Any signal from body manufacturer CAN

Any signal from Use signal from the body manufacturer CAN.

Permanent LOW (signal ID 1000)

Function deactivated

Hand brake 

Activation input (bit signal) as condition for PTO.

Parameterization possibilities:

Hand brake applied (signal ID 1055)

Querying of the hand brake for activation of the PTO

Inquiry deactivated (signal ID 300B)

Querying of this condition is deactivated

Selector lever in position "N", with transmission 722.6 

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

Activation input (bit signal) as condition for PTO.

Parameterization possibilities:

Selector lever in position "N" (signal ID 10F2)

Querying of the neutral position of the gear selector lever for activation of the PTO

Inquiry deactivated (signal ID 300B)

Querying of this condition is deactivated

Idle 

Activation input (bit signal) as condition for PTO.

Parameterization possibilities:

Engine at idle (signal ID 113D)

Querying of the engine idle (accelerator pedal module not depressed) for activation of the PTO

Inquiry deactivated (signal ID 300B)

Querying of this condition is deactivated

Clutch 

IMPORTANT The availability of the signal "Clutch fully depressed" depends on the vehicle equipment.

Activation input (bit signal) as condition for PTO.

IMPORTANT This query cannot be deactivated. The PTO could otherwise be damaged.

It is only possible to select between "Clutch depressed" and "Clutch fully depressed".

Parameterization possibilities:

Clutch depressed (signal ID 11C4)

Inquiry whether clutch is fully depressed for the activation of the PTO

Clutch fully depressed (signal ID 10F1) is deactivated

Inquiry whether clutch is fully depressed for the activation of the PTO

The transmission neutral position switch is fitted on vehicles with the following equipment:

The clutch pedal switch for the inquiry "Clutch pedal fully depressed" is fitted on vehicles with code (MJ6) Engine start and stop system.

Freely parameterizable CAN signal 

Activation input as condition for PTO.

The procedure is as follows:

Parameterization possibilities:

Any signal

Any signal can be used here.

Inquiry deactivated (signal ID 300B)

Querying of this condition is deactivated

Further parameters for freely parameterizable CAN signal "PTO" 

These must be parameterized in the PTO properties:

PTO feedback 

Input to which the PTO feedback is connected.

Parameterization possibilities:

Any discrete input can be used.

Any discrete input

Permanent LOW (signal ID 1000)

Function deactivated

IMPORTANT If you want to evaluate the feedback via the PSM control unit, you must set the parameter "PTO feedback is evaluated" to "YES" in the PTO properties.

Vehicle speed limit for PTO shutoff 

The current vehicle speed is compared with the parameter "Vehicle speed limit for power take-off shutoff" and the result of this comparison is used as the input signal for activation of the PTO. If the parameter "Vehicle speed limit for power take-off shutoff" is set to 255, checking of the vehicle speed is deactivated in the function module "PTO".

Rpm limit for PTO 

This rpm limit is output if the PTO is active.

For technical reasons you can only adjust the parameter in the range of 1200 to 2500 rpm.

Clutch waiting time 

The clutch status must be "Clutch depressed or fully depressed" for a period of 5 s in order for this condition to be regarded as fulfilled in the function module "Solenoid valve actuation".

For technical reasons, this parameter is permanently stored in the PSM control unit. No settings can be made here.

Signals of "PTO" function which are stored in signal pool 

Request for working speed control (PTO function module) 

This bit signal is used as a request signal for working speed control. It is set by the function module "PTO".

This signal is set when the inputs of the PTO function module are valid and one of the power take-off requests (discrete, CAN Body manufacturer) is active.

Actuate power take-off solenoid valve (function module "PTO") 

This bit signal is used as the request signal for actuation of the power take-off solenoid valve. It is set by the function module "PTO".

This signal is set when the inputs of the PTO function module are valid and one of the power take-off requests (discrete, CAN Body manufacturer) is active.

IMPORTANT If you want to perform actuation of the PTO via the PSM control unit, you must set "Actuate PTO solenoid valve via PSM" to "YES" in the PTO properties and place the signal "Status of solenoid valve actuation (module "Power take-off")" on one of the discrete outputs of the PSM control unit.

Description of associated function modules 

Function module "PTO" 

PTO 

G10887859Courtesy of MERCEDES-BENZ USA

Function module "Solenoid valve actuation" 

Solenoid valve actuation 

G10887860Courtesy of MERCEDES-BENZ USA
Parameterizable special module (PSM) control unit component description GF54.21-D-5005H