Engine speed control - Scania Group

22:10-087 Issue 2 en-G

Engine speed control
Function
FunctionEngine speed control is used to control the engine speed without using the accelerator pedal, for example by using controls outside the cab. The function can, among others, be used to increase the engine speed when using a power take-off.

There are four (4) modules for control of the engine speed (Engine speed control 1-4), all have similar setting possibilities. The 4 modules can be adapted and activated individually.

Note:The vehicle must be equipped with BCI functionality with variant code 5837A to be able to use the 4 modules.

B 1 (19)© Scania CV AB 2014, Sweden

Engine speed controlBehaviour

BehaviourThere are a number of parameters for the modules that can be set in SDP3 (Scania Diagnos & Programmer 3).

Parameters common to all modules.• EXT switch

• Order of priority

• Engine speed change at stepped control

• Maximum engine speed while braking

• Maximum torque when regulating engine speed

• Conditions for regulating the engine speed with a gear engaged

• Potentiometer, lower voltage limit

• Potentiometer, upper voltage limit

• Engine speed when changing gear, automatic gearbox

Parameters valid individually to all modules.• Type of control

• Regulator characteristics

• Fixed engine speed

• Upper engine speed limit

• Lower engine speed limit

• Accelerator pedal engaged when controlling the engine speed

• Increase in engine speed

• Upper vehicle speed limit

Not until after activation, the engine speed can be controlled in the active module.

© Scania CV AB 2014, Sweden

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For parameter setting, see more under heading Parameters that can be adjusted using SDP3.


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Description of some of the parametersOrder of priorityThe order of priority between the modules is set by a parameter. The parameter can be set to either Number order or Latest used.

Number orderThe module with the lowest number will be activated.

If several modules have been requested active at the same time, then only the one with the lowest number will be active. If the one with the lowest number is switched off, the module with the next lowest number will be active.

Latest usedThe module that was last used will be activated.

If several modules have been requested active, then only the latest one activated will be active.

If the latest activated module is deactivated, the speed control will be deactivated even if previously activated controls are still requested.


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Type of controlFor each module, 4 different types of control can be selected.

• Switch for cruise control

• Fixed value

• Analogue control

• External CAN

Fixed engine speed is used, for example, when operating cranes and refrigeration units.

The other 3 can be used as variable control of the engine speed. They can, for exam-ple, be used for power-requiring power take-offs where the engine speed is adapted to the current load.

Switch for cruise controlThe engine speed is controlled by the switches for the cruise control if its main switch is in the ON position.

• The speed increases each time the ACC button is pressed and decreases when the RET button is pressed. The speed increase can be adjusted in SDP3.

• When the OFF button is pressed, the engine speed will go down to idling. The lat-est saved value can be resumed by pressing the RES button.

• The set engine speed can be stored in the memory by holding down the RES but-ton for at least 3 seconds.

Preset stored value is 900 rpm. If a value has never been saved, the engine will go to 900 rpm when the RES button is pressed.

To achieve the same control possibilities, for example depending on chassis, this functionality can also be request via BIC.


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More information on CAN is found in the CAN document under Electrical systems.

Note:The OFF button switches off the switch for the cruise control but not the active con-trol. The characteristics set in the control still apply, such as switched off accelerator pedal and governor characteristics except for the engine speed going down to idling.

Fixed valueThe engine assumes a fixed speed that can be adjusted with SDP3.

Analogue controlFor analogue control of the 4 modules, a potentiometer is required. The engine speed is controlled by the voltage supplied on pin 11 in the C493 connector. The speed that corresponds to a certain voltage can be adjusted in SDP3.

External CANThe engine speed assumes the value sent on the External CAN bus in the message: (BodyworkEngineRequest1:EngineSpeedRequest).


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More information on propeller shafts and propeller shaft angles is found in the doc-ument General information about power take-offs under Power take-offs and hy-draulics.

Governor characteristicsThe engine speed can be controlled by different characteristics. This is done by using different so-called governors which give the engine different characteristics.

The are 3 different governors.

• ‘Soft’ Governor that makes the engine respond more slowly but softer to load changes compared to a normal governor.

• ‘Normal’ Governor used by the engine as standard.

• ‘Hard’ Governor that gives a faster but also harder engine speed control compared to the normal governor.

Note:If the power take-off is provided with propeller shafts and the propeller shaft angles are not balanced correctly, under unfavourable circumstances vibrations may be caused in the powertrain.

Proceed as follows to prevent problems:

• Take care to fit the propeller shafts correctly.

• First of all, use a normal or soft speed governor.


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Engine speed controlSafety functionality

More information on power take-offs is found in the documents under Power take-offs and hydraulics.

Safety functionalityThe following conditions reduce the engine speed to idling to prevent the engine and brakes from working against one another:

• Service brake or parking brake applied when a gear is engaged and the clutch ped-al is not depressed1

• Service brake or parking brake applied on vehicles with torque converters when the torque converter’s mechanical gear (lock-up) is activated.

The following conditions reduce the engine speed to the stored value to prevent the engine and brakes from working against one another:

• Service brake or parking brake applied on vehicles with torque converter when the torque converter's mechanical gear (Lock-up) is not activated. Protects the torque converter from overheating.

• When a gear is engaged from the neutral position in an automatic gearbox with active engine speed control, the engine speed will drop to the stored value. If the engine speed is higher, the gearbox safety function prevents the gear from being engaged. When the gear has been engaged, the engine returns to the controlled en-gine speed.

1. The condition does not apply to vehicles if a split shaft power take-off is engaged.


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Engine speed controlActivation

ActivationThe following conditions must be fulfilled on activation:

• EXT switch activated

• The gear position must correspond to the parameter setting, see Conditions for controlling the engine speed in the table under the heading Parameters that can be adjusted using SDP3.

• The vehicle speed must be below the value, see Upper vehicle speed limit for de-activation in the table under heading Parameters that can be adjusted using SDP3.

If these conditions are fulfilled, the function can be activated via BIC (Bodywork In-terface Configuration) and External CAN.

With or without EXT switch (sequential check)• With EXT switch: The EXT switch must be activated after the starter key has

been turned to the drive position. Only then can the selected function be activated.

• Without EXT switch: Activation of the function has no dependency on the EXT switch.


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Engine speed controlChassis conditions

the factory

Alternative Variant codeWith 5837A

arness from cab to frame 7+7+7-pin 2411F

arness in frame 2 m 3023A

8 m 3023D

12 m 3023C

Chassis conditionsVehicle production period Preparations from

Production site Chassis serial number Option- BCI functionality

Södertälje -

Zwolle -

Angers - If required

São Bernardo do Campo - Bodywork cable h

Bodywork cable h


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Engine speed controlParameters that can be adjusted using SDP3

Possible value From factory GroupWithout Spring-loaded

Bodywork adaptation2 positions

Spring-loaded

Parameters that can be adjusted using SDP3The parameters are adjusted under functions in SDP3.

The parameters in the table below apply to all 4 modules, Engine speed control 1-4.

Parameter ExplanationEXT switch Controls whether the EXT switch should be active or

not


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Number order Number order

Powertrain

Latest used

10-200 rpm 50 rpm

500-2,000 rpm 800 rpm

300-5,100 Nm (engine depend-ent)

5,100 Nm

Activated Activated

Deactivated, gear engaged

Deactivated, parking brake

0-5 V 0.5

0-5 V 4.5

0-5,000 rpm 600 rpm

Possible value From factory Group
Order of priority Sets the order of priority between Engine speed con-
trol 1-4, if several requests are made at the same time.

Engine speed change at stepped control

Sets how much the engine speed should change for each short press of the button on a switch for the cruise control.

Maximum engine speed while braking

Sets the highest engine speed permitted during brak-ing, when the torque converter’s lock-up clutch is not activated.

Maximum torque when regu-lating engine speed

Sets a torque that the engine must not exceed when en-gine speed control is active.

Conditions for regulating the engine speed with a gear en-gaged

Sets when the function for control of the engine speed can be used.

Potentiometer, lower voltage limit

Sets the voltage that corresponds to a potentiometer value of 0%.

Potentiometer, upper voltage limit

Sets the voltage that corresponds to a potentiometer value of 100%.

Engine speed when changing gear, automatic gearbox

Set the highest engine speed that will permit a gear to be engaged from the neutral position.

Parameter Explanation


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Possible value From factory Grouphen con- Switch for cruise control Fixed value

Power-train

Fixed value

Analogue control

External CAN

changed Normal Normal

Soft

Hard

engine 300-3,000 rpm 500 rpm

ine 300-3,000 rpm 3,000 rpm

e speed 300-3,000 rpm 300 rpm

control With Without

Without

gine 50-1,000 rpm/s 1,000 rpm/s

engine 5-150 km/h Parking brake

Parking brake

The parameters in the table below are included in a set for each of the modules, Con-trol of engine speed 1–4.

Parameter ExplanationType of control Sets the type of signal which should be used w

trolling the engine speed.

Governor characteristics Sets whether the control of engine speed for a load should be soft, hard or normal.

Fixed engine speed Sets the engine’s fixed speed at control of thespeed.

Upper engine speed limit Sets the highest permitted engine speed at engspeed control.

Lower engine speed limit Sets the lowest permitted engine speed at engincontrol.

Accelerator pedal engaged when con-trolling the engine speed

Sets if the accelerator pedal is to be engaged atof the engine speed.

Increase in engine speed Sets the speed increase, that is how fast the enspeed is to change.

Upper vehicle speed limit Sets vehicle speed limit for deactivation of thespeed control function


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Engine speed controlSignal type and activation of function

1 - 10

C259

+24 V

17

C259

344

947

2

31

3

Activation by +24 V

1 - 10

C259C259

344

948

2

1

3

Activation by grounding

Signal type and activation of functionExample of connection using BICT, +24 V and groundThis description shows a connection inside the cab. Information on how to make the connection with an extension harness on the chassis is found in the document Cable harness cab and frame (22:10-080).

Proceed as follows:

1. Connect the activation cable to any input pin in connector C259.

2. By using BICT (Bodywork Interface Configuration Tool) the function is allocat-ed to the selected pin.

The function is ready for activation.

Part information and connection positions

The parts can be purchased from a Scania dealer.

1 For example, a switch Connected to any pin on C259

2 Fuse 5 A

Fitted by bodybuilder

3 Cable Cable cross-section min. 0.75 mm²



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BCI master C-pin (1–10), High or low

Activate enginespeed control

346

6951 2

BCI

1. The pin selected to activate the function.

2. Function: Engine speed control 1-4.

Signal type Activation methodPin (BWE) +24 V to selected pin on C259

or

Grounding of selected pin on C259


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4

3

C493

C493

340

792

Activation via External CAN

More information on CAN is found in the CAN documents under Electrical systems.

Connection via External CANThis description shows a connection inside the cab. Information on how to make the connection with an extension harness on the chassis is found in the document Cable harness cab and frame (22:10-080).

To be able to make a connection via External CAN, the following is required:

• The vehicle is equipped with BCI functionality variant code 5837A

• The parameter for External CAN is activated

The connection is made directly to connector C493 (External CAN-low to pin 3 and External CAN-high to pin 4).

BodyworkEngineRequest1: EngineControlModule selects which module that is to be active.

If a module set to External CAN is activated, the value for the signal BodyworkEngi-neRequest1: EngineSpeedRequest will be used.

The parts can be purchased from a Scania dealer.

Signal type MessageCAN BodyworkEngineRequest1: EngineControlModule

BodyworkEngineRequest1: EngineSpeedRequest


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1 - 10

C259

+24 V

17

C259

350

183

2

31

3

10

11

12

C493

R1

R2R3

56

4

C493

Activation by +24 V

Example of connection for control of engine speed using potentiometer +24 VThis description shows a connection inside the cab. Information on how to make the connection with an extension harness on the chassis is found in the document Cable harness cab and frame (22:10-080).

Proceed as follows:

1. Connect the activation cable to any input pin in connector C259.

2. Connect the resistors as shown in illustration.

3. By using BICT (Bodywork Interface Configuration Tool) the function is allocat-ed to the selected pin.

The function is ready for activation.

Part information and connection positions1 For example, a switch Connected to any pin on C259

2 Fuse 5 A


3 Cable Cable cross-section min. 0.75 mm²


4 Resistor R1 R1, see Calculation of resistance values be-low


5 Resistor R2 R2, see calculation of resistance values below


6 Potentiometer R3, see calculation of resistance values below



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met potentiome-

Calculation of resistance valuesThe resistance values R1, R2 and R3 should be selected so that the upper and lower voltage limits for the potentiometer correspond to the parameters set.

Fault code is set if the signal level is outside the 0.2-4.8 V interval. The limit levels are in the source code and are not affected by the choice of measurement area via pa-rameter setting and connected resistors.

Calculation of resistance

U1 Lower voltage limit, corresponds to 0% accelerator pedal actuation

U2 Upper voltage limit, corresponds to 100% accelerator pedal actuation

R1 Resistor, to produce 0% accelerator pedal actuation

R2 Resistor, to produce 100% accelerator pedal actuation

R3 Potentiometer, select resistance between 200-500 ohm. The type should be Certer.

R1 = R3 ·U1

ohm, R2 = R3 ·5 - U2

ohmU2 - U1 U2 - U1


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Engine speed controlExamples

Example 1 Example 2 Example 3 Example 4 Fixed value Switch for cruise

controlAnalogue control External CAN

Spring-loaded Spring-loaded Spring-loaded Spring-loaded

Number order Number order Number order Number order

- 50 rpm - -

800 rpm 800 rpm 800 rpm 800 rpm

- - - -

Activated Deactivated Deactivated Deactivated

- - 0.5 -

- - 4.5 -

600 rpm 600 rpm 600 rpm 600 rpm

Fixed value Fixed value Analogue control External CAN

Normal Soft Normal Soft

700 rpm - - -

3,000 rpm 1,100 rpm 1,100 rpm 1,100 rpm

300 rpm 500 rpm 500 rpm 500 rpm

Without With With With

1,000 rpm/s 1,000 rpm/s 1,000 rpm/s 1,000 rpm/s

Parking brake 150 km/h 150 km/h 150 km/h

Examples4 suggestions of how the parameters for engine speed control can be set, Fixed value, Switch for cruise control, Analogue control and External CAN.

Parameter From factory

EXT switch Spring-loaded

Order of priority Number order

Engine speed change at stepped control 200 rpm

Maximum engine speed while braking 800 rpm

Maximum torque when regulating engine speed 5,100 Nm (engine dependent)

Conditions for regulating the engine speed with a gear engaged

Activated

Potentiometer, lower voltage limit 0.5

Potentiometer, upper voltage limit 4.5

Engine speed when changing gear, automatic gearbox 600 rpm

Type of control Fixed value

Governor characteristics Normal

Fixed engine speed 500 rpm

Upper engine speed limit 3,000 rpm

Lower engine speed limit 300 rpm

Accelerator pedal engaged when controlling the engine speed

With

Increase in engine speed 1,000 rpm/s

Upper vehicle speed limit Parking brake


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Documents

Engine speed control - Scania Group