Volvo Penta D2-40B "software invalid"

[sailor_leo]

Hi everyone,

as I could read in this forum there are some typical issues with the Mdi of the VP D2-40 engine.

The problem I have right now is that on the display of the Tachometer where usually the engine hours will be seen, I get the message "software init" and after a few seconds "software invalid".

Does anyone know this behavior? Is that a mdi or tachometer problem? My tachometer hast the partnumber 3819792.

Thank you!


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[sailor_leo]

I forgot to mention that the engine runs fine, just the hours, rpm and temperature won't show


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[DougR]

Occasionally, over the years there have been cases where updates to control modules and the like has resulted in situations where early generation software devices will not function with later, updated modules.

However if you have not changed any of the components of your system, then it could be one of the components is failing, or a harness or a pin within a harness has come loose. Most likely to check components will require replace parts.

I'll see if I can find out if there has been a common problem, and let you know.

DougR

[sailor_leo]

Thank you for your reply Doug. I could only find one post describing the exact same situation as I have.

http://www.justanswer.com/boat/7x3oe-volvo.html

Since it was intermittent at the beginning, I hope that is problem to fix the problem, just need to find out what would cause the tachometer to report software invalid.


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[DougR]

The way your system works is that the MDI box collects information from the various sensors on the engine, converts that info into CAN bus language and sends that data to the tachometer and gauges on the "multi link" cable.

Because neither of the instruments are working, you probably have a fault with the connecting cable or the MDI box.

I suggest a careful examination of the multi link cable from the MDI box to the tach. Check for loose or pushed back pins or corrosion on the pins. If this doesn't help you probably have an MDI box problem.

DougR

[sailor_leo]

Thanks for your reply Doug.

The temperature gauge is also not working, but in my understanding it receives the signal forwarded from the tachometer, right?

Is there a way to check only the temperature gauge without connecting the tachometer?


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[DougR]

Yes, the instrument data flows to the tach first and then on to the separate gauges.

I don't think there is any easy way to bypass the tach and connect to the temp gauge only.

The fact that both tach and temp gauge are not working indicates to me that either the data stream isn't reaching the tach, or it is corrupted.

The electrical system manual details the troubleshooting procedures for the "on engine" components of the system, but there isn't really any procedure to check the gauges other than to swap them out.

DougR

[sailor_leo]

I will several tests when I am back to the boat.

If I only connect the 12V + and - wires of the tach I would expect to see the Volvo Penta logo instead of "software invalid", do you know if my assumption is right?


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[Davo70]

I have the exact same problem but with my D2-55.
Tacho and fuel gauge not working but engine starts, runs and stops as normal.
I get the same message on the LCD.
Have checked all cables and connections with them all being in pristine condition.
I bit the bullet and ordered a new MDI, arrived today.
I’m hoping this is the problem as its a significant cost and I hate to think where this could lead to.

[Davo70]

Originally Posted by Davo70

I have the exact same problem but with my D2-55.
Tacho and fuel gauge not working but engine starts, runs and stops as normal.
I get the same message on the LCD.
Have checked all cables and connections with them all being in pristine condition.
I bit the bullet and ordered a new MDI, arrived today.
I’m hoping this is the problem as its a significant cost and I hate to think where this could lead to.

Just replaced the MDI and problem still exists.
Not sure where to go from here?
My thoughts are either replace multi link harness or Tacho??????
sailor_leo and DougR, any updates on what you guys were doing?

[sailor_leo]

Hi Davo70,

I have decided to buy a new MDI for around 500USD and luckily it solved the problem. Good luck in finding the solution for your problem!

[Scubaseas]

It's a Bosch relay for a Dynastart system. Correction to my previous post if anyone is actually trying to run a generator as a motor power the D+ or armature wire. Powering the field was done to magnetize the generator. Sorry. The 60s were a bit hazy......

Looks like there are plenty of solutions online by searching "Volvo Dynastart"