I'm gonna have to read this again later. . too much thinkin right now:{ :{
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Engine/Transmission (1998.5 - 2002) The Ultimate VP44 Q&A Thread
- Thread starter ToolManTimTaylor
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Diesel Freak,
Looks like your dealing with somebody who knows.
All that sounds great but Cummins was thinking way ahead of the rest of us. The ECM/VP44 in our trucks do not us the standard SAE J1939 protocol. There is a section in the standards book that was left open for manufactures to use their own proprietary PGN/PDUs
Remember your post from 3/19/02
I have been trying to read the messages
being transmitted out of the CANBus plug on a 2000 Dodge. I have a
prototype board consisting of a Microchip PIC, a MCP2510, and a PCA
82C251. I believe that I have set all of the parameters correctly
for the 2510, but when I set it to listen for all messages I receive
only one message repeatedly with an ID that is NOT defined in the
1939 standard (HS-1939). Is this port really using 1939? Has anyone
successfully received valid J1939 messages from this port? I only
want to read some basic parameters that should be broadcast
periodically from the ECM (throttle position, engine RPM, etc. ) so I
do not believe that I need to transmit to the bus (but I could be
wrong). Any help would be greatly appreciated.
This was the message you copied from the CAN users group board. It was written by my co conspirator. We have come along way since then. The only J1939 standards broadcast from the ECM are total milage and total fuel used.
Looks like your dealing with somebody who knows.
All that sounds great but Cummins was thinking way ahead of the rest of us. The ECM/VP44 in our trucks do not us the standard SAE J1939 protocol. There is a section in the standards book that was left open for manufactures to use their own proprietary PGN/PDUs
Remember your post from 3/19/02
I have been trying to read the messages
being transmitted out of the CANBus plug on a 2000 Dodge. I have a
prototype board consisting of a Microchip PIC, a MCP2510, and a PCA
82C251. I believe that I have set all of the parameters correctly
for the 2510, but when I set it to listen for all messages I receive
only one message repeatedly with an ID that is NOT defined in the
1939 standard (HS-1939). Is this port really using 1939? Has anyone
successfully received valid J1939 messages from this port? I only
want to read some basic parameters that should be broadcast
periodically from the ECM (throttle position, engine RPM, etc. ) so I
do not believe that I need to transmit to the bus (but I could be
wrong). Any help would be greatly appreciated.
This was the message you copied from the CAN users group board. It was written by my co conspirator. We have come along way since then. The only J1939 standards broadcast from the ECM are total milage and total fuel used.
Last edited:
I was hoping that there was someone else on here that subscribed to the CANlist... . I get updated daily, but I usually delete them unless the title grabs my attention. The individual that sent me that last message works at Texas Instruments... that is all I know about him/her.
My dealings at work include mostly LONworks, and a little Devicenet..... so all I know about CAN and some of the SAE protocols are what I have dug up off the net.
WeirCummin, I am sure that your "co conspirator" saw the message I posted that prompted that reply.
there is a lot of info in this thread..... but we have only scratched the surface..... Does anyone else have anything to contribute?
My dealings at work include mostly LONworks, and a little Devicenet..... so all I know about CAN and some of the SAE protocols are what I have dug up off the net.
WeirCummin, I am sure that your "co conspirator" saw the message I posted that prompted that reply.
there is a lot of info in this thread..... but we have only scratched the surface..... Does anyone else have anything to contribute?
Help me out here... am I correct in assuming that while the SAE left a section of the protocol open to the OEM's they still have to follow the same basic J1939 Format?
Yes
Even though it is proprietary, it still follows the standard for HS-1939
Even though it is proprietary, it still follows the standard for HS-1939
just dug this up
VP44 Injector Pump System
The VP44 injection pump was introduced on the Cummins ISB as a stop gap
measure to meet 1998 emissions standards before a common rail fuel system was
ready for production. For Dodge Ram pickups, the ISB engine was used in all
trucks built after January 1, 1998. A common rail system is being road tested
now, and reliable rumors say the the VP44 will be replaced by a common rail in
2003 models. For those with 1998-2002 Rams, here are some details about the VP44
pump.
To meet environmental regulations for a variety of engine applications,
Cummins designed an ECU to which they could download different engine control
programs without making any physical changes to the engine. This electronic
engine control unit (ECU) is installed in a sealed box that is mounted directly
to the cylinder block of the engine. The ECU communicates with the VP44 fuel
injection pump through a high-speed 2-way CAN-BUS data-link.
There is no direct connection from the throttle to the injector pump. Inputs
from engine sensors and the throttle position are used by the ECU to determine
how much fuel is injected, and when. The ECU uses sensor and throttle position
inputs to compute the appropriate "load", then the controller obtains the
fueling rate information from look-up tables, sometimes called maps, stored in
ROM. From these a value is determined that represents the desired amount of fuel
to be delivered to the engine. This value is then communicated to the injector
pump.
The VP44 injection pump uses a set of mechanical plungers to pressurize the
fuel, and a mechanical distributor to route the fuel to the correct injector. An
electronic controller converts the fuel information sent from the ECU into
mechanical control of the fuel delivery by opening and closing fuel spill ports
inside the pump mechanism. The pump returns information to the ECU regarding its
current operating state.
Bosch VP44 Injector PumpCummins ECU
General Information from the ZEXEL site:
The VP44 systemwas developed to meet emission standards and reduce
fuel consumption. VP44 is a direct-injection type fuel-injection system
for small- to medium-size diesel engines. To generate the high injection
pressures needed for direct-injection, The VP44 uses an internal cam disk
and radially opposed plungers to pressurize the fuel from two directions.
The VP44 controls the injection rate and injection timing using two
electromagnetic valves. Also, the electronic control unit is divided into
two, with a compact control unit mounted directly on the pump and a larger
Engine Control Module mounted on the engine block.
Fuel System - General Information from Cummins
The VP44 is an electronic fuel injection pump manufactured by Bosch®,
that can vary fueling and injection timing based on input from the
electronic control module (ECM). This pump has its own electronic control
unit, the fuel pump control module (FPCM), which contains fueling, timing,
and diagnostic data. The fuel pump control module (FPCM) communicates with
the engine controller (ECM) to obtain information on desired fueling and
timing. The fuel pump control module (FPCM) responds to the ECM's commands
by consulting the fueling data and timing in its memory and actuating the
fueling and timing solenoids.
A fuel temperature sensor is located inside the VP44 pump to
compensate for changes in the temperature of the fuel. The pump also
contains a speed sensor (IAT) that gives the fuel pump control module
(FPCM) data on the position and speed of the pump shaft. A reference pulse
that marks top dead center (TDC) of cylinder No. 1 is sent from the ECM
once every pump revolution. By comparing this reference pulse from the ECM
to the position signal from the speed sensor (IAT), the fuel pump control
module (FPCM) can reference the pump's position in relation to the
engine's position. This allows the fuel pump control module (FPCM) to
adjust the pump timing to compensate for minor position differences
between the fuel pump shaft and the engine camshaft. If the difference
between the pump position and engine position becomes too great, then a
fault will be logged in the fuel pump control module (FPCM).
In addition to the engine position reference pulse, the fuel pump
control module (FPCM) also receives timing and fueling commands from the
ECM. The fuel pump control module (FPCM) controls the timing and fueling
through two solenoids located in the pump. The timing solenoid controls
the position of a cam ring inside the pump by varying internal transfer
pump pressure. The cam ring has evenly spaced lobes around its inner
diameter. The pumping plungers ride on rollers that rotate inside this cam
ring. The rollers follow the inner diameter of the cam ring and push the
pumping plungers inward whenever a cam lobe is encountered, thus building
injection pressure. By rotating the cam ring with the timing solenoid, the
fuel pump control module (FPCM) is able to advance and retard the
injection timing by making the rollers contact the cam lobes either
earlier or later.
The second solenoid in the pump is used to meter fuel to the
injectors. The solenoid opens the fuel metering valve to allow fuel from
the supply pump to flow into the pumping chamber. Once the pumping chamber
is charged with fuel, the solenoid valve closes. This traps the fuel in
the chamber and allows injection pressure to build. The fuel is routed to
the correct injector by the pump distributor. The distribution port on the
distributor aligns with one of the six outlet ports to distribute fuel to
a given injector. Once the desired amount of fuel has been injected, the
solenoid valve opens, causing the pressure in the pumping chamber to bleed
down, which ends injection. The cycle then begins again for the next
cylinder.
The fuel injection pump (VP44) is an electronic rotary distributor pump.
The pump performs four basic functions:
Producing the high fuel pressure required for injection
Metering the exact amount of fuel for each injection cycle
Distributing the high-pressure, metered fuel to each cylinder at the
precise time
Varying the timing relative to engine speed.
A cam ring with three plungers, a rotor, and an electronically
controlled fueling solenoid valve is used to develop and distribute the
high pressure required for injection.
A worn or damaged internal transfer pump, plunger, or fueling valve
can affect the pressure and the amount of fuel injected, thus reducing the
power from the engine. Generally, if the fuel-injection pump is injecting
fuel from one outlet, it will deliver from all outlets.
VP44 Timing Principles
Timing in the VP44 is controlled by an internal timing piston coupled
to a cam ring inside the pump. The timing piston is moved by fuel
pressure. The amount of fuel pressure in the timing piston assembly
housing is controlled by an internal transfer pump and a pulsating timing
solenoid valve. As the pump speed increases, the fuel pressure to the
timing piston assembly also increases.
Based on the inputs from the fuel pump control module (FPCM), the
timing solenoid valve pulses to vary the pressure to move the timing
piston, which results in the cam ring moving to the desired position to
achieve the commanded timing. The more pressure created by the internal
transfer pump and timing solenoid valve, the more the timing will advance;
therefore, timing range capability is increased at higher rpms.
The ISB engine is equipped with an electric-powered lift pump. Fuel
flow begins as the fuel lift pump pulls fuel from the supply tank. This
electric lift pump supplies low-pressure fuel (10 to 12 psi) to the filter
head, through the filter, and then to the electronic distributor injection
pump.
The electronic distributor pump builds the high injection pressures
required for combustion and routes the fuel through individual
high-pressure fuel lines to each injector.
When the high-pressure fuel reaches the injector, the pressure lifts
the needle valve against the spring tension to let the fuel enter the
combustion chamber.
Any leakage past the needle valve enters the fuel drain manifold in
the cylinder head. The fuel in the manifold exits at the rear of the
cylinder head and is routed to the fuel tank. The fuel that is returned
from the fuel injection pump is also routed back to the fuel tank.
What other engines use the VP44 Injection Pump?
BMW 320d
Ford Focus td
Opel dti
Saab
VAG V6 tdi
John Deere 6. 8L diesel
Case tractors and construction equipment
VP44 Injector Pump System
The VP44 injection pump was introduced on the Cummins ISB as a stop gap
measure to meet 1998 emissions standards before a common rail fuel system was
ready for production. For Dodge Ram pickups, the ISB engine was used in all
trucks built after January 1, 1998. A common rail system is being road tested
now, and reliable rumors say the the VP44 will be replaced by a common rail in
2003 models. For those with 1998-2002 Rams, here are some details about the VP44
pump.
To meet environmental regulations for a variety of engine applications,
Cummins designed an ECU to which they could download different engine control
programs without making any physical changes to the engine. This electronic
engine control unit (ECU) is installed in a sealed box that is mounted directly
to the cylinder block of the engine. The ECU communicates with the VP44 fuel
injection pump through a high-speed 2-way CAN-BUS data-link.
There is no direct connection from the throttle to the injector pump. Inputs
from engine sensors and the throttle position are used by the ECU to determine
how much fuel is injected, and when. The ECU uses sensor and throttle position
inputs to compute the appropriate "load", then the controller obtains the
fueling rate information from look-up tables, sometimes called maps, stored in
ROM. From these a value is determined that represents the desired amount of fuel
to be delivered to the engine. This value is then communicated to the injector
pump.
The VP44 injection pump uses a set of mechanical plungers to pressurize the
fuel, and a mechanical distributor to route the fuel to the correct injector. An
electronic controller converts the fuel information sent from the ECU into
mechanical control of the fuel delivery by opening and closing fuel spill ports
inside the pump mechanism. The pump returns information to the ECU regarding its
current operating state.
Bosch VP44 Injector PumpCummins ECU
General Information from the ZEXEL site:
The VP44 systemwas developed to meet emission standards and reduce
fuel consumption. VP44 is a direct-injection type fuel-injection system
for small- to medium-size diesel engines. To generate the high injection
pressures needed for direct-injection, The VP44 uses an internal cam disk
and radially opposed plungers to pressurize the fuel from two directions.
The VP44 controls the injection rate and injection timing using two
electromagnetic valves. Also, the electronic control unit is divided into
two, with a compact control unit mounted directly on the pump and a larger
Engine Control Module mounted on the engine block.
Fuel System - General Information from Cummins
The VP44 is an electronic fuel injection pump manufactured by Bosch®,
that can vary fueling and injection timing based on input from the
electronic control module (ECM). This pump has its own electronic control
unit, the fuel pump control module (FPCM), which contains fueling, timing,
and diagnostic data. The fuel pump control module (FPCM) communicates with
the engine controller (ECM) to obtain information on desired fueling and
timing. The fuel pump control module (FPCM) responds to the ECM's commands
by consulting the fueling data and timing in its memory and actuating the
fueling and timing solenoids.
A fuel temperature sensor is located inside the VP44 pump to
compensate for changes in the temperature of the fuel. The pump also
contains a speed sensor (IAT) that gives the fuel pump control module
(FPCM) data on the position and speed of the pump shaft. A reference pulse
that marks top dead center (TDC) of cylinder No. 1 is sent from the ECM
once every pump revolution. By comparing this reference pulse from the ECM
to the position signal from the speed sensor (IAT), the fuel pump control
module (FPCM) can reference the pump's position in relation to the
engine's position. This allows the fuel pump control module (FPCM) to
adjust the pump timing to compensate for minor position differences
between the fuel pump shaft and the engine camshaft. If the difference
between the pump position and engine position becomes too great, then a
fault will be logged in the fuel pump control module (FPCM).
In addition to the engine position reference pulse, the fuel pump
control module (FPCM) also receives timing and fueling commands from the
ECM. The fuel pump control module (FPCM) controls the timing and fueling
through two solenoids located in the pump. The timing solenoid controls
the position of a cam ring inside the pump by varying internal transfer
pump pressure. The cam ring has evenly spaced lobes around its inner
diameter. The pumping plungers ride on rollers that rotate inside this cam
ring. The rollers follow the inner diameter of the cam ring and push the
pumping plungers inward whenever a cam lobe is encountered, thus building
injection pressure. By rotating the cam ring with the timing solenoid, the
fuel pump control module (FPCM) is able to advance and retard the
injection timing by making the rollers contact the cam lobes either
earlier or later.
The second solenoid in the pump is used to meter fuel to the
injectors. The solenoid opens the fuel metering valve to allow fuel from
the supply pump to flow into the pumping chamber. Once the pumping chamber
is charged with fuel, the solenoid valve closes. This traps the fuel in
the chamber and allows injection pressure to build. The fuel is routed to
the correct injector by the pump distributor. The distribution port on the
distributor aligns with one of the six outlet ports to distribute fuel to
a given injector. Once the desired amount of fuel has been injected, the
solenoid valve opens, causing the pressure in the pumping chamber to bleed
down, which ends injection. The cycle then begins again for the next
cylinder.
The fuel injection pump (VP44) is an electronic rotary distributor pump.
The pump performs four basic functions:
Producing the high fuel pressure required for injection
Metering the exact amount of fuel for each injection cycle
Distributing the high-pressure, metered fuel to each cylinder at the
precise time
Varying the timing relative to engine speed.
A cam ring with three plungers, a rotor, and an electronically
controlled fueling solenoid valve is used to develop and distribute the
high pressure required for injection.
A worn or damaged internal transfer pump, plunger, or fueling valve
can affect the pressure and the amount of fuel injected, thus reducing the
power from the engine. Generally, if the fuel-injection pump is injecting
fuel from one outlet, it will deliver from all outlets.
VP44 Timing Principles
Timing in the VP44 is controlled by an internal timing piston coupled
to a cam ring inside the pump. The timing piston is moved by fuel
pressure. The amount of fuel pressure in the timing piston assembly
housing is controlled by an internal transfer pump and a pulsating timing
solenoid valve. As the pump speed increases, the fuel pressure to the
timing piston assembly also increases.
Based on the inputs from the fuel pump control module (FPCM), the
timing solenoid valve pulses to vary the pressure to move the timing
piston, which results in the cam ring moving to the desired position to
achieve the commanded timing. The more pressure created by the internal
transfer pump and timing solenoid valve, the more the timing will advance;
therefore, timing range capability is increased at higher rpms.
The ISB engine is equipped with an electric-powered lift pump. Fuel
flow begins as the fuel lift pump pulls fuel from the supply tank. This
electric lift pump supplies low-pressure fuel (10 to 12 psi) to the filter
head, through the filter, and then to the electronic distributor injection
pump.
The electronic distributor pump builds the high injection pressures
required for combustion and routes the fuel through individual
high-pressure fuel lines to each injector.
When the high-pressure fuel reaches the injector, the pressure lifts
the needle valve against the spring tension to let the fuel enter the
combustion chamber.
Any leakage past the needle valve enters the fuel drain manifold in
the cylinder head. The fuel in the manifold exits at the rear of the
cylinder head and is routed to the fuel tank. The fuel that is returned
from the fuel injection pump is also routed back to the fuel tank.
What other engines use the VP44 Injection Pump?
BMW 320d
Ford Focus td
Opel dti
Saab
VAG V6 tdi
John Deere 6. 8L diesel
Case tractors and construction equipment
wow, this thread just died... ... . what happened?
Wouldn't you figure that there shouldn't be a need for a Cam position sensor being the Vp44 Has an integral "Timing" unit within it's own unit. Piont is this ... . The Cummins relys on the cam position sensor to control various aspects of the combustion process as well as giving the PCM a few juicy tidbits to look at for the trans to look at. (Am I waaay off base here?) the reason I am going this direction is of what had just happened to me ... .....
As fast as the truck died is as fast as she is up and running again ... ... ... WITH THE SENSOR STILL IN THE CUMMINS BOX >>>>>> AT CUMMINS METROPOWER IN STOCK ... ... on the shelf even!
no MIL light no check guages ... ... . nothing but July 4th fun with people in the back and traffic at a stanstill ... . running perfectly. Anyways why would the pcm & ECM rely on a frail sensor such as this when the readings can simply be taken from the inj. pump? It seems that my Blue Chip FMC is dead on accurate with engine rpm's and the tach is delayed ... ... so beit.
When the truck was in limp mode the factory tach was dead but the blue chip was very much alive and reading fine (Thank gawd cause I had to go into nutral at stoplights at arround 1000 rpm's and that's how I relyed on doing so)
Now For the 10$ Q:
How much of a PITA am I looking at to get this Cam Positioning sensor out from behind underneath the Vp44? And do I have to do anything special to it after?
As fast as the truck died is as fast as she is up and running again ... ... ... WITH THE SENSOR STILL IN THE CUMMINS BOX >>>>>> AT CUMMINS METROPOWER IN STOCK ... ... on the shelf even!
no MIL light no check guages ... ... . nothing but July 4th fun with people in the back and traffic at a stanstill ... . running perfectly. Anyways why would the pcm & ECM rely on a frail sensor such as this when the readings can simply be taken from the inj. pump? It seems that my Blue Chip FMC is dead on accurate with engine rpm's and the tach is delayed ... ... so beit.
When the truck was in limp mode the factory tach was dead but the blue chip was very much alive and reading fine (Thank gawd cause I had to go into nutral at stoplights at arround 1000 rpm's and that's how I relyed on doing so)
Now For the 10$ Q:
How much of a PITA am I looking at to get this Cam Positioning sensor out from behind underneath the Vp44? And do I have to do anything special to it after?
Tim,
I dunno how hard it will be to get to but it is as behind the pump as you could possibly get. I Don't remember if it just threads in or what.
good luck!
Later,
Mark
I dunno how hard it will be to get to but it is as behind the pump as you could possibly get. I Don't remember if it just threads in or what.
good luck!
Later,
Mark
oh My GAWD! Mark youre not kidding one word OUCH! the human wrist is not meant to do that sort of thing!
Here is a link......
This thread got a little side tracked with ECM discussions but is still a good source of info. There is another thread talking about pressures that could be useful so here it is.
About 10 reply's in there is a discussion on what a Bosch rep had to say about pressures. Interesting info.
https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=53683
Garrett
This thread got a little side tracked with ECM discussions but is still a good source of info. There is another thread talking about pressures that could be useful so here it is.
About 10 reply's in there is a discussion on what a Bosch rep had to say about pressures. Interesting info.
https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=53683
Garrett
Bug Out
, This thread's for you
, This thread's for you
Wow 7 years later (almost) and look how some things we knew then and now differ ever so slighly LOL
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Issue 128 – Digital Version
Digital Magazines
FREE!
TDR Test Drive - Digital Edition
Renew
Subscribe
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Back Issues
Subscription Status
Address Change Form
Buyer's Guides
Ram Diagnostic Trouble Codes
The Perfect Collection
The Perfect Collection Vol. II
TSB Updates
Dodge/Cummins Historical Overview
Cameron Collection
What Makes Us Tick?
Product Showcase
Advertising
