Split shaft power take-off activation via BWS. General information about the function. Operation with the vehicle in motion and stationary

Size: px

Start display at page:

Download "Split shaft power take-off activation via BWS. General information about the function. Operation with the vehicle in motion and stationary"

Godfrey Burke
6 years ago
Views:

1 General information about the function General information about the function The split shaft power take-off is mainly used when very large power outputs are required. The advantage is that the half shafts are disengaged and all power can be used to drive the power take-off. The power take-off is located between the gearbox and the rear axle. Note: The split shaft power take-off can only be controlled by the BWS control unit. In this way other control units in the vehicle receive information that the power take-off is engaged. This is necessary for things such as the engine speed control to work properly. Operation with the vehicle in motion and stationary Normally the function is used for stationary operation as the power transmission to the half shafts is disengaged. Operation with the vehicle in motion is possible, on vehicles intended for street cleaning, for example. In this case a power source other than the ordinary engine must be engaged to the vehicle half shafts, a hydraulic drive for example. 11:60-06/09 Issue 8 en-gb 1 (18)

2 General information about the function Direct gear It is very important that the direct gear be used in the main gearbox to minimise the heat generated in the gearbox during power take-off operation. Direct gear means that the gear is selected so that the gearbox has a gear ratio of 1:1. For a gearbox with overdrive (GRSO) the next highest gear should be used. For a gearbox without overdrive (GR, GRS) the highest gear should be used. On Allison gearboxes 4th is the direct gear. When the power take-off is engaged in accordance with the instructions contained in this document, the Opticruise or Allison control unit will engage the direct gear automatically when the following conditions have been met: The control unit has received an acknowledgement signal: The gear lever has been moved to position D and the automatic position (Opticruise) or Drive position (Allison). The clutch has been depressed (does not apply to fully automated Opticruise). Note: This activation means that the driver does not need to change up to the direct gear each time the power take-off is activated. 11:60-06/09 Issue 8 en-gb 2 (18)

3 General information about the function Acknowledgement signal Information that the power take-off is activated is displayed in the instrument cluster. When the power take-off has been activated and the half shafts disengaged, an acknowledgement signal must always be sent to the BWS control unit. The acknowledgement signal is always a grounding signal. The control unit informs other systems in the vehicle. The status of the power take-off is required to permit engine speed control when a gear is engaged and the parking brake is activated, i.e. during stationary operation. Acknowledgement for activation of power take-off in newer instrument cluster The status of the power take-off is required to permit engine speed control when the wheel brakes are being used when the vehicle is in motion and a gear is engaged. This occurs when the vehicle is being driven via the power take-off; for instance when some street cleaning vehicles are being driven hydraulically. Several control units need to know the status of the power take-off to prevent fault codes being generated because of differences in speed calculations based on wheel speeds and propeller shaft speeds. The difference occurs when the power take-off is being used, since the wheel speed is 0 but not the propeller shaft speed. Acknowledgement for activation of power take-off in older instrument cluster :60-06/09 Issue 8 en-gb 3 (18)

4 General information about the function Engine speed control If the split shaft power take-off has been engaged in accordance with the instructions in this document, certain conditions, normally used to protect the powertrain, do not work. This is necessary to control the engine speed for this application 1. Scania recommends Remote engine speed control as an alternative to engine speed control when the power take-off is engaged. More information on engine speed control is available in the documents under Engine speed. If another engine speed control option is used; for example Hand throttle or Limited hand throttle, the following can occur: The engine control unit switches to controlling vehicle speed rather than controlling engine speed if the anticipated vehicle speed is higher than 20 km/h. This takes place if the road speed sensor is not moved. See next section. Touching the clutch and brake pedals deactivates engine speed control. 1. The standard safety conditions that normally reduce engine speed to idling to prevent the engine and brakes from working against each other are a) Service brake or parking brake applied when a gear is engaged and the clutch pedal is not depressed. b) Service brake or parking brake applied on vehicles with torque converter, when the torque converter s mechanical gear (lock-up) is activated. 11:60-06/09 Issue 8 en-gb 4 (18)

5 General information about the function Moving the road speed sensor The road speed sensor must be located on the propeller shaft after the split shaft power take-off for the following reasons: The road speed sensor will indicate the correct speed during power take-off operation as well. The tachograph will register the correct vehicle use. Temporary fault codes in the brake and gearbox control units will be avoided. These fault codes do not impede operation, but do make it more difficult to identify real faults. If the engine speed is controlled by the Hand throttle or Limited hand throttle function, the engine regulator will switch to cruise control mode when the road speed sensor registers speeds above 20 km/h. Avoid using these engine speed control options when driving a split shaft power take-off. Opticruise allows the driver to change gear as long as no propeller shaft speed is being registered. 11:60-06/09 Issue 8 en-gb 5 (18)

6 General information about the function Activation and deactivation conditions The split shaft power take-off activation and deactivation logic is normally contained in the equipment selected for bodywork. In addition a number of extended conditions can be set in the BWS control unit. Example: Further information on engine speed control can be found in the document Overview of engine speed control. Parking brake conditions Neutral position conditions Upper engine speed limit for activation Lower engine speed limit for activation Upper vehicle speed limit for activation Lower vehicle speed limit for activation Accelerator pedal deactivation Recommendations: Always use the parking brake conditions for activation and deactivation. Use Accelerator pedal deactivation when the vehicle bodywork is a concrete pump with a large range, skylift, or something similar. Applies to engine speed control modes 1, 3 and 4. 11:60-06/09 Issue 8 en-gb 6 (18)

7 General information about the function Fully automated Opticruise On vehicles with fully automated Opticruise, the accelerator pedal controls the clutch. The following applies to the clutch control: The clutch closes when the accelerator pedal is depressed. Closing of the clutch is controlled by how much the accelerator pedal is depressed. The more the accelerator pedal is depressed, the quicker it closes. The clutch opens if the accelerator pedal is released before the clutch is fully closed. Put the drive mode selector in position N (neutral) to disengage the power takeoff. Note: The parameter value Braking in operation with split shaft power take-off controls whether the clutch should open when the brake pedal is applied or whether it should remain closed. The default value is for the clutch to open. Protective logic for disengagement When the power take-off is disengaged and the driving axles are re-engaged, the torque and rotational speed of the propeller shaft from the main gearbox must be reduced to levels which are sufficiently low for engagement and disengagement. Normally the user does this by engaging neutral in the main gearbox before switching off the power take-off switch. Note: Scania recommend that a protection circuit is connected to protect the vehicle against operator faults which may cause mechanical damage. The function of the protection circuit is to keep the power take-off engaged until the output rotational speed is sufficiently low. 11:60-06/09 Issue 8 en-gb 7 (18)

8 Chassis conditions Chassis conditions General information The function can be connected on vehicles with a chassis serial number listed in the summaries in this section. If a specific operational case is required for vehicles with lower chassis serial numbers, contact a Scania dealer for information about how to carry out connection. Note: Note the difference in chassis serial number series for vehicles intended for operation with the vehicle stationary and in motion. 11:60-06/09 Issue 8 en-gb 8 (18)

9 Chassis conditions Vehicles for stationary operation Vehicles with a manual gearbox with or without Opticruise: Vehicles with automatic gearbox: Vehicle production period Vehicle production period Production site Chassis serial number Production site Chassis serial number Södertälje Södertälje Zwolle Zwolle Angers Angers Vehicles for operation with the vehicle in motion Vehicles with Euro 3 engines: Vehicles with Euro 4, Euro 5 and Euro 6 engines: Vehicle production period Vehicle production period Production site Chassis serial number Production site Chassis serial number Södertälje Södertälje Zwolle Zwolle Angers Angers :60-06/09 Issue 8 en-gb 9 (18)

10 Chassis conditions Obligatory option for all gearbox alternatives Preparations from factory Option Alternative Variant code BWS With 3319A Electrical preparation for split shaft power take-off With 3545A Note: Customer option 3545A only covers the electrical preparation. The bodybuilder must fit switches, indicator lamps, solenoid, power take-off and confirmation sensor itself. The figure gives an overview of customer options 3319A and 3545A. V152 and C231 are located on the inside of the left frame member. C231 is terminated without a connector. C A 3319 A 3545 A :60-06/09 Issue 8 en-gb 10 (18)

11 Connection instructions Connection instructions Alternative 1: Manual gearbox with or without Opticruise General information about the connection The road speed sensor is moved to the propeller shaft after the split shaft power take-off. For Opticruise: Opticruise automatically selects the direct gear when the acknowledgement signal is activated. The gear is activated when the clutch is depressed. Opticruise always activates manual mode during power take-off operation. If the direct gear is not proposed the driver must change up to it every time the power takeoff is activated. Road speed sensor Scania recommends that the same number of teeth as on the original pulse wheel are used when the road speed sensor is moved to the output propeller shaft. If the number of teeth (pulses per revolution) is changed, the SOPS file must be updated using SDP3 (Scania Diagnos & Programmer 3). The following variants are available: Example: Concrete pump truck Option Rotational speed constant for road speed sensors Pulses per revolution Variant code A D The 1541B variant code for transfer gearbox is not shown in the table as Scania does not recommend the combination of transfer gearbox and split shaft power take-off. 11:60-06/09 Issue 8 en-gb 11 (18)

12 Connection instructions Signal type and activation of function Signal type Signal direction Notes Ground connection to C260-4 a In Activating the solenoid, which activates the power take-off Ground connection to C260-3 In Acknowledgement signal for activated power take-off b a. Alternatively, C260-5 (activation with +24 V) or C or C (external CAN) can be used. Adjusted using SDP3. b. Must indicate when the split shaft power take-off has engaged. Only after this, engine speed control, for example, is permitted. Parameters that can be adjusted using SDP3 Note: Follow proposals in the table, in particular the following parameters: Acknowledgement from other equipment Conditions for applied parking brake (other equipment) Parameter Possible value From factory For this connection System Selection of signal input for activation signal Active low Active low Active low for power take-off 3 or other equipment Active high CAN Acknowledgement from power take-off 3 or With With With other equipment Without Light indication (indicator lamp) for power With Without With BWS take-off 3 Without Without Type of activation (power take-off 3 or other Manual Manual Manual equipment) Automatic Automatic Drive position Drive position 11:60-06/09 Issue 8 en-gb 12 (18)

13 Connection instructions Parameter Possible value From factory For this connection System Conditions for applied parking brake (power One None One take-off 3 or other equipment) Two Two None Conditions for neutral position (power take-off One a None One a BWS 3 or other equipment) Two a Two a None Braking in operation with split shaft power Open clutch Open clutch Open clutch GMS take-of b Keep the clutch closed Keep the clutch closed Lower deactivation limit, engine speed (power No lower limit No lower limit No lower limit take-off 3 or other equipment) 200 2,000 r/min 200 2,000 r/min Upper deactivation limit, engine speed (power No upper limit No upper limit No upper limit take-off 3 or other equipment) 200 2,000 r/min 200 2,000 r/min Lower deactivation limit, vehicle speed (power No lower limit No lower limit No lower limit BWS take-off 3 or other equipment) km/h km/h Upper deactivation limit, vehicle speed (power No upper limit No upper limit No upper limit take-off 3 or other equipment) km/h km/h Cylinder balancing Active Active Active EMS Inactive Inactive a. On vehicles with a manual gearbox these conditions require that the gearbox is fitted with a separate neutral position sensor. b. This parameter was introduced on 23 October :60-06/09 Issue 8 en-gb 13 (18)

14 Connection instructions Part information and connection positions 1 Switch Closing Fitted by the bodybuilder 2 Confirmation sensor Fitted by the bodybuilder 3 Solenoid Fitted by the bodybuilder S171 S171 The cable cross-sectional area must be at least 1.5 mm 2. Grounding and connectors are factory fitted. The parts are available from Scania dealers. C C260 1 C493 C V152 S231 2 S231 V :60-06/09 Issue 8 en-gb 14 (18)

15 Connection instructions Alternative 2: Automatic gearbox General information about the connection To move the road speed sensor, see option 1. The conditions controlling power take-off activation and deactivation are set in the BWS control unit (see the illustration below) using SPD3. A summary of modifiable parameters can be found in option 1. The mechanical activation of the power take-off is carried out by the solenoid. A confirmation sensor indicates that the driving axles have been disengaged and that the power take-off has been engaged, and lamp 2 indicates the change to the driver. Relay A short-circuits the circuit between C449 pin 6 and C449 pin 4. The shortcircuiting indicates to the gearbox control unit that the driving axles have been disengaged and the power take-off has been engaged. Relay B short-circuits C260 pin 3 to ground in order to indicate the change to other control units in the vehicle. Relay C is activated when C449 pin 5 indicates that the gearbox is locked in fourth gear (the Allison function Lock-up 4th gear). The output which activates the relay is active low (grounding). Lamp 3 indicates when the gearbox has engaged the direct gear and when it is permitted to start increasing the engine speed and torque. Example: Fire engine with water pump :60-06/09 Issue 8 en-gb 15 (18)

16 Connection instructions Reprogramming the Allison gearbox The Allison gearbox control unit must be reprogrammed to a Novation package, designed for the purpose, which includes a Pump Mode Program. Reprogramming is carried out by an Allison dealer or workshop. This example is based on Allison Vocation Package 124, Fire and Emergency Vehicles. The advantage of this example is that all the necessary electrical cables and pins are accessible through connector C449. Other options require pins to be switched. Always compare with Allison s connection instructions for the relevant Vocation Package. Note: SDP3 will only recognise a Vocation Package which has been programmed by Scania. The reason is that the part number is not valid. Fault codes can be read out but not connected to their explanatory text. 11:60-06/09 Issue 8 en-gb 16 (18)

17 Connection instructions Part information and connection positions 1 Switch Closing Fitted by the bodybuilder 2 Lamp 1 Fitted by the bodybuilder 3 BWS Obligatory option Fitted by Scania 4 Solenoid Fitted by the bodybuilder 5 Confirmation sensor Fitted by the bodybuilder 6 Lamp 2 Fitted by the bodybuilder 7 Relay A Fitted by the bodybuilder 8 Relay B Fitted by the bodybuilder 9 Relay C Fitted by the bodybuilder 10 Lamp 3 Fitted by the bodybuilder +24V 1 C BWS C C V C GMS Allison:143 Allison:117 Allison:103 Allison: The grey fields in the illustration show what has been prepared by Scania. The white fields show the connections that the bodybuilder must carry out. The parts are available from Scania dealers. 11:60-06/09 Issue 8 en-gb 17 (18)

18 Connection instructions Example of disengagement protective logic The solid lines in the figure on the right show the connection of the protective logic for the split shaft power take-off together with an Allison gearbox. This example is based on Allison Vocation Package 124, Fire and Emergency Vehicles. Protective logic prevents disengagement being carried out before the gearbox rotational speed is sufficiently low. The relay activates input C493 pin 3 (ground connection) for as long as C449 pin 10 indicates that the output shaft speed from the gearbox is above a certain rotational speed. The rotational speed level can be controlled by an Allison dealer or workshop. Logic conditions for activation and deactivation of output C493 pin 14 are set in the BWS control unit using SDP3. The input C493 pin 3 and output C493 pin 14 are called Power take-off 1 (other equipment) in SDP3, and must be set to Other equipment The diodes prevent reverse voltage on the outputs of the BWS control unit. 1 Relay Fitted by the bodybuilder 2 BWS Obligatory option Fitted by Scania 3 Diodes Fitted by the bodybuilder +24V C BWS 3 +24V GMS C493 C Allison: Allison:117 3 C Allison:103 Allison: Allison: V Disengagement protective logic with an Allison gearbox More information is available in the document Safety precautions The cable cross-sectional area must be at least 1.5 mm 2. The cables are fitted by the bodybuilder. The parts are available from Scania dealers. 11:60-06/09 Issue 8 en-gb 18 (18)

Activation of a split shaft power take-off. Function

Activation of a split shaft power take-off. Function Function Function The function is intended to activate the power take-off from the driver area and from outside the cab. The power take-off is controlled by the BCI control unit. For the control of the