Volvo Penta Genset Engine Electrical Interface

Oct. 15, 2019

Electrical interface

General

This document describes how the Volvo Penta industrial engines equipped with the control systems EMS and EMS2 may be controlled.

There are a number of interfaces available to control the engine. The interfaces are:

• Bus interface

• CIU

• DCU

The common thing about the three first interfaces is that the engine is controlled over two serial communication buses. The CIU and DCU uses the bus interface to communicate with the engine.

IMPORTANT!

If non Volvo Penta equipment is connected to the communication buses there is always a risk that the safety of the system is jeopardized.

Abbreviations

BAM Broadcast Announce Message

CAN Controller Area Network

DEF Diesel Emission Fluid

EATS Engine After Treatment System

EIC Engine Interface Connector

EECU Engine Electronic Control Unit

EMS Engine Management System

EMS 2 EMS used on TAD734GE, D9,

TAD125xVE, D13 and D16 engines FMI Failure Mode Identifier

OEM Original Equipment Manufacturer

SPN Suspect Parameter Number

VP Volvo Penta

Relevant dokumentation

• 7748665

Electrical interface specification industrial engines EMS and EMS2

• SAE J1939-73 • SAE J1939-71

Engine control interface

Volvo Penta industrial engines can be controlled in three different ways. Via bus interface, CIU or DCU. The bus interface is used by those who makes there own control system that and wants to control the engine over SAE J1939 and J1587. Volvo Penta provided two different systems to control the engines, CIU that provides a number of digital/analogue outputs to control the engine. And DCU that has all buttons included in the unit but still provides some digital/analogue inputs and outputs.

CIU

This is the interface for those who wants to make there control panel or non bus based control unit.

DCU

This is the interface for those who wants a complete unit that is ready to run the engine without make any button. But the possibility to make some customization is still here.

The DCU is equipped with a display that shows engine data and diagnostics translated to text.

Electrical interface

Bus interface

8-pole deutsch connector recepticle.

Pin Description

1 CAN H

2 CAN L

3 Battery –

4 Battery +

5 Ignition and stop request if energized to run 6 Stop request energized to stop

7 J1587A

8 J1587B

Power up sequence

The system powers up when the ignition is switched on.

Start

A start request is addressed by the start signal. The engine will then start to crank and it will continue to do so until one of the following conditions becomes true.

• The start signal goes inactive.

• The engine speed exceeds a stated limit, typical about 480 rpm.

• The cranking time exceeds a stated limit, typical about 20 s. 30 s for genset engines.

Bus interface

Associated message:

J1939: Start request in VP Status

J1587: Start request in PPID 98

CIU

Associated hardware/input:

Start request.

DCU

Associated hardware/input:

Start request.

Power down sequence

To perform a power down the following sequence shall be performed:

1 Switch off the ignition

2 Send a stop request to the system.

3 When the power down sequence is finished the engine will stop communicating.

Auto shutdown will power down the system if the ignition is switched off. Different length of time sequences are being used. (Running engine will continue to run until a stop request is sent to the system).

External stop

External stop is placed in the 8-pole connector on pin 6.

Energized to STOP/RUN

Default external stop function is set to Energized to STOP. To use the stop function as Energized to STOP, apply EMS supply voltage on Pin 6 to stop the engine.

By option or changing a parameter it can be set to Energized to RUN. To use the stop function as Energized to RUN, Pin 6 needs EMS supply voltage for the engine to start and run. To stop the engine EMS supply voltage needs to be removed from Pin 6.

Energized to RUN on Pin5

If the function “energized to run” is used the extra stop is on pin 5 together with the ignition.

The main power MUST NOT be switched off before the power down sequence is finished.

Stop

A stop request is addressed by the stop signal and will stop the engine.

Bus interface

Associated message:

J1939: Stop request in VP Status

J1587: Stop request in PPID 98

CIU

Associated hardware/input:

Stop request.

DCU

Associated hardware/input:

Stop request.

Throttle (Synchronizing/Load sharing)

Versatile

The driver pedal demand is realized by the throttle request signal. The signal is interpreted as a 0-100% request where 0% means idle speed and 100% maximal engine speed. This demand will only be overridden if an error occur that may damage the engine or a request with the CAN-message TSC1.

Genset

This is used for controlling the engine speed in order to synchronize and to perform load sharing. 50% throttle corresponds to 1500 or 1800 rpm.

Bus interface

Associated message:

J1939: Throttle in VP Status

J1587: PPID 132

CIU

Associated hardware/input:

Potentiometer supply, signal and ground.

DCU

Associated hardware/input:

Increase decrease engine speed buttons or potentiometer supply, signal and ground.

Torque speed control

It is possible to override the throttle that is sent in VP Status. This is done with TSC1. When controlling the engine speed from the gearbox (SA = 0x03) it always have the highest priority.

Bus interface

Associated message:

J1939: TSC1

J1587: N/A

CIU

Associated message:

J1939: TSC1

J1587: N/A

DCU

Associated message:

J1939: TSC1

J1587: N/A

Governor mode

The engine is normally running in isochronal mode. If there is a need for a smoother controller this can be realized by an active droop mode signal. When the governor mode signal is active then droop functionality is added to the engine speed controller.

Bus interface

Associated message:

J1939: Governor mode in VP Status

J1587: N/A

CIU

Associated hardware/input:

Governor mode request.

DCU

Associated hardware/input:

Available in the menu.

Idle switch

Versatile

If the throttle request is malfunctioning (meaning that there is an electrical fault on the potentiometer or the cable harness) then the idle switch can be used for limp home driving.

If there is a fault on the pedal signal then the engine will go to idle speed. If then the idle switch first goes active (meaning that the driver has released the pedal) and then goes inactive (meaning that the driver is pressing the pedal down) then the engine will slowly ramping up the engine speed. The engine speed will be ramped up to maximal 80 % of normal maximal engine speed. When releasing the pedal the engine will immediately go down to idle speed.

Genset

If an idle request is sent to the engine it will go to idle speed if the engine unloaded.

Bus interface

Associated message:

J1939: Idle request in VP Status

J1587: N/A

2.11.2 CIU

Associated hardware/input:

Idle request.

CIU

Associated hardware/input:

Idle request.

DCU

Available in the menu

Preheat

This function is not valid for 124xGE.

When a preheat request is received the engine will activate the preheat device if the following conditions are fulfilled.

• The coolant temperature is low.

• The engine is not running.

The preheat device will be activated for a time dependent on the coolant temperature. The engine will also decide, using the coolant temperature, if after heating should be used.

Preheating will be terminated immediately if the driver starts cranking.

It is possible for the costumer, using Volvo Penta Parameter setting tool, to choose if preheating should be activated immediately after turning on the ignition (prior to same conditions as above).

Bus interface

Associated message:

J1939: Preheat request in VP Status

J1587: N/A

CIU

Associated hardware/input:

Preheat request.

DCU

Associated hardware/input:

Available in the menu.

Frequency select

This function is only valid for genset applications.

The frequency switch is used for changing the nominal engine speed (i.e. switching between 1500 and 1800 rpm). For safety reasons the frequency can only be changed when the engine is stopped.

EMS2 systems

To make a system reset request stop wait 2 second after the last stop request. Then change the state of frequency select to the desired engine speed. Then send a stop request within 10 seconds after the first stop. The frequency select signal must change value during the frequency change. I.e. if the engine runs at secondary speed and the frequency select signal requests primary engine speed when the first stop is issued, the signal has to be switched to secondary followed by primary engine speed, before the second stop request is issued.

It is possible to change the frequency using the Volvo Penta aftermarket tool.

Bus interface

Associated message:

J1939: Frequency select in VP Status and & diagnostic request in VP Status.

J1587: N/A

CIU

Associated hardware/input:

Frequency select.

DCU

Associated hardware/input:

Available in the menu.

Engine protection override

It is possible to request engine protection override. When such a request is received the engine will deactivate the engine protection for a predefined time.

Genset engines

The engine protection is disabled as long as the request is active and for another 10s.