Volvo Penta D2 MDI failure - what are the typical symptoms?

[dunedin]

There have been quite a few threads on the recalls for VP D2 series MDIs.

But can anybody explain the symptoms that would allow you to recognise that an MDI is faulty?

Potentially related to other D2 thread, but don’t want to jump to conclusions , so thought would also ask specifically about MDI symptoms, from those that have suffered failures.
Thanks

 

[pvb]

This is worth a read - http://nordkyndesign.com/engine-reliability-a-look-at-the-volvo-penta-mdi-black-box/

 

[dunedin]

This is worth a read - Engine Reliability: A Look at the Volvo Penta MDI Black Box | Nordkyn Design

Thanks - that was very interesting. Not least as I discovered the MDI on my boat when I got it in Dec 2014 is a part number that was only made from 2014. So it was already on its second MDI then (and presumably the engine hours were 2-3 years more than as sold!).
We had intermittent problems in 2016 and were assured by engineer 2 that these were MDI caused, so we paid a fortune for a new MDI (our third as it transpires) - but in fact it didn’t help, and it was an intermittent battery isolator fault that engineer 3 found (true parts cost under a tenner, wrong parts cost major ouch, as also included a new AGM crank battery that engineer 1 said was the solution).
This reinforces the article’s recommendation - don’t even think about replacing an MDI unless the battery supply is bullet proof.

In the absence of any better ideas, think I might put the old MDI back in. Having first checked the battery connections and going to replace battery isolators again just in case.

 

[Graham376]

Why not bin the box and hard wire it?

 

[Neeves]

Based on conversations with an Australian perspective and having talked it through with the owner of a Volvo servicing and distribution business is that there are no symptoms. One day everything works perfectly the next day, or the same day - the engine is dead (the MDI simply fails).

Volvo agents, service points, are given a list of product, or batch numbers, from which faulty units have been supplied. I'm not sure what they are meant to do with these numbers - it was implied to me that owners encompassed by these batch numbers would be contacted and replacement units supplied (but that might have been marketing speak).

My understanding is that the danger is you may go off for the day and have no issues, the weather turn against you and just when you need to enter a marina (or port) you engine is, basically, dead and useless. You can short the starter motor with a screw driver - but this trick does not appear in any manual and it is hardly convenient. There may be better ways to start the engine.. You would also need to turn the engine off manually by closing the fuel line (there may be other methods)

I have not looked at the link that pvb supplied - but your best route is to find a list of part numbers, batch numbers within which there have been faulty units and if your unit(s) is/are suspect then make the necessary noises to Volvo (though my understanding is that Volvo have not been very sympathetic - but this may be very wrong as lacking sympathy seems very unprofessional, if not a disgrace, for a known fault). If you are outside the faulty units numbers - you seem to have a good chance that the issues will not occur - as they do seem to have had some successes or some batches with no faults - and the issues seem to be historic and not from current deliveries.

Jonathan

 

[dunedin]

According to the local VP main dealer the part number of my current MDI is not on the recall list - 22458451 W1618

Had wrongly been advised to replace the MDI previously, when it was an intermittent battery switch issue - so swapped that MDI back on, part number - 21558929 W1047

Will see what that does for us. Of course the challenge with intermittent issues, both work fine in marina and with engineer on board - then fail when at sea

Just because not part of a bad batch does not mean can’t fail thereafter. As the article linked to in post #2 suggests, attaching electronics to the side of the heat exchanger with vibrations and high temperature is hardly brilliant design. But insufficient cable length to move without more substantial work.
And yes re-engineering to remove MDI altogether might be nice — but would be a major project when everybody is too busy to help.

 

[Samwise2111]

Hello,
I am looking for owners of VP MDI-boxes for mechanically controlled engines (D1 and D2) that have failed seemingly without any external cause.
Symptoms: Panel stays dead, no button pressure is recognised. Nothing burnt on the PCB. All seems fine - but it does not work.
I have been working with someone who routinely analyses automotive ECUs, and we would like to do more research on this in order to show a repair route.
Mine was repaired, so it is no longer good for research. ;-)

 

[Slowtack]

My D1 30 of 2017 vintage and relatively light use has had three MDI failures... 4th box fine so far... Bypass switches installed for glowplugs and starter motor installed as backup. Online searches indicate possible cause being a back EMF from the fuel shut off solved by a simple diode across the solenoid....earlier engines had relays in the control box rather than the solid state version in current engines and did not suffer this problem....

 

[dunedin]

I have also had MDI failure on my 2011 D2-55F

Had an emergency bypass start switch fitted this year

 

[andyc352]

I have a D2-55F and although the MDI has never given any problems, I fitted a heavy duty 12V push switch to enable starting if the MDI fails.

 

[wizard]

This is worth a read - Engine Reliability: A Look at the Volvo Penta MDI Black Box | Nordkyn Design

After reading that article I designed my own hard wired system as the author pointed out there many components that will fail at various times -it was generally a unit not fit for purpose.
When our lives depend on the engine in certain situations you have to be certain its going to work when you need it most.

 

[Daydream believer]

I have purchased a push button for a byepass switch to start the engine in event of MD1 failure. However, I am not sure where exactly to fit the 2 wires.
Can anyone describe EXACTLY which terminal on the md1 unit I should connect to & where the other wire should go please
Thx

 

[andyc352]

You just need to connect the battery +ve terminal on the MDI to the start terminal on the MDI through the switch. The switch and wiring need to be heavy duty to take the starter current. I didn’t bother connecting the “preheat” terminal for the glow plugs as my engine never needs preheat here in Portugal.

 

[Samwise2111]

My D1 30 of 2017 vintage and relatively light use has had three MDI failures... 4th box fine so far... Bypass switches installed for glowplugs and starter motor installed as backup. Online searches indicate possible cause being a back EMF from the fuel shut off solved by a simple diode across the solenoid....earlier engines had relays in the control box rather than the solid state version in current engines and did not suffer this problem....

Unless your MDI-box has been sitting on the shelf for quite a while before being out into your boat, its PCBs should have looked like on the attached photos.
PCB 1:
1 LPC2119FBD64 NXP LPC2119 µC with CAN
2 HC4052 RT65711 TXD17 27E 74HC4052 4-Channel Analog Multiplexer/Demultiplexer
3 2904 SA6U (oder SAGU) LM2904 OpAmp
4 6163D Infineon PROFET® BTS 6163 D, High Side Power Switch
5 24C01CI SN1608 MCP I2C EEPROM
6 2901 ST MZRR737 STM LM2901 4x Comparator
7 NCV4269A5G ON PPJJ11 OnSemi NCV4269A Low Dropout Regulator, 5V, 3,3V 150mA
8 2901 ST MZRR737 STM LM2901 4x Comparator
9 NXP A1040/C AWW000 nD744 NXP TJA1040 CAN Transceiver
10 EPCOS C104 7405 39
11 6163D Infineon PROFET® BTS 6163 D, High Side Power Switch

PCB 2:
1 ST G EXY Z731
2 ST G MIMY ???
3 12CWQ04FN V P639G Vishay 12CWQ04FN, 2x Schottky, 2x 6A
5 W77 /16 BCP53 BCP53 PNP Transistor
6 011N04L Infineon IPB011N04L N-Channel Power MOSFET, 180A

So the stop solenoid is switched by an Infineon PROFET® BTS 6163 D, datasheet is here. This is not just a simple MOSFET - and I do not think it is easily killed. In fact, it was a smart move to get rid of the relays. Relays are sensitive to vibrations, and some genius decided to bolt the MDI-box onto the engine...
Which raises the following questions:
- What were the error symptoms with your 3 MDI-boxes?
- Did you have a look at the PCB? Are you sure it was the PROFET switch?
- Do you still have one of the MDIs?
Perhaps there was a common root cause for the failure of your first three boxes, and that root cause is still waiting to knock out your fourth, too.

 

[Daydream believer]

You just need to connect the battery +ve terminal on the MDI to the start terminal on the MDI through the switch. The switch and wiring need to be heavy duty to take the starter current. I didn’t bother connecting the “preheat” terminal for the glow plugs as my engine never needs preheat here in Portugal.

There are 3 main terminals on the underside of the MD1- How do I know which 2 they are please?
I have a 2023 engine, imported just as I bought it from Volspec, so latest offering.
May I also ask- Am I not just energising the solenoid. So wires do not need to be excessively big.

 

[Major Tom]

Symptoms - revs start hunting down to idle and back, and the stop button stops working. It never cut completely. Sometimes the on or start button refuses to work, but it's intermittent. Box replaced under warranty - no further problems, touch wood.

 

[andyc352]

There are 3 main terminals on the underside of the MD1- How do I know which 2 they are please?
I have a 2023 engine, imported just as I bought it from Volspec, so latest offering.
May I also ask- Am I not just energising the solenoid. So wires do not need to be excessively big.

Yes, the switch is just energising the solenoid so no huge cables needed. I think the middle terminal is battery +ve (red) and the red/yellow wire is to the solenoid but check the schematic on the side of the MDI and it’s obvious which is which.

 

[Samwise2111]

Symptoms - revs start hunting down to idle and back, and the stop button stops working. It never cut completely. Sometimes the on or start button refuses to work, but it's intermittent. Box replaced under warranty - no further problems, touch wood.

Button problems can be caused by
- the panel or cabling,
- cold contacts around one of the comparators (6) on PCB 1, or the LPC itself,
- a broken MLCC at the input to the comparator. This was the issue in my case. An easy fix for about 0.01€.
At least you did not have to pay for it. But I assume they took the defective MDI back?

 

[Major Tom]

Yes, I worked through eliminating all those, but the eng went straight for the MDI switch out, and that was it. And he kept it.

 

[Slowtack]

Unless your MDI-box has been sitting on the shelf for quite a while before being out into your boat, its PCBs should have looked like on the attached photos.
PCB 1:
1 LPC2119FBD64 NXP LPC2119 µC with CAN
2 HC4052 RT65711 TXD17 27E 74HC4052 4-Channel Analog Multiplexer/Demultiplexer
3 2904 SA6U (oder SAGU) LM2904 OpAmp
4 6163D Infineon PROFET® BTS 6163 D, High Side Power Switch
5 24C01CI SN1608 MCP I2C EEPROM
6 2901 ST MZRR737 STM LM2901 4x Comparator
7 NCV4269A5G ON PPJJ11 OnSemi NCV4269A Low Dropout Regulator, 5V, 3,3V 150mA
8 2901 ST MZRR737 STM LM2901 4x Comparator
9 NXP A1040/C AWW000 nD744 NXP TJA1040 CAN Transceiver
10 EPCOS C104 7405 39
11 6163D Infineon PROFET® BTS 6163 D, High Side Power Switch

PCB 2:
1 ST G EXY Z731
2 ST G MIMY ???
3 12CWQ04FN V P639G Vishay 12CWQ04FN, 2x Schottky, 2x 6A
5 W77 /16 BCP53 BCP53 PNP Transistor
6 011N04L Infineon IPB011N04L N-Channel Power MOSFET, 180A

So the stop solenoid is switched by an Infineon PROFET® BTS 6163 D, datasheet is here. This is not just a simple MOSFET - and I do not think it is easily killed. In fact, it was a smart move to get rid of the relays. Relays are sensitive to vibrations, and some genius decided to bolt the MDI-box onto the engine...
Which raises the following questions:
- What were the error symptoms with your 3 MDI-boxes?
- Did you have a look at the PCB? Are you sure it was the PROFET switch?
- Do you still have one of the MDIs?
Perhaps there was a common root cause for the failure of your first three boxes, and that root cause is still waiting to knock out your fourth, too.

Many thanks for all your I formation... I will open an old box and have a look... I don't know about root causes other than bad design... If they had stuck with relays all would be fine... As for symptoms.. There were none... Just instantaneous failure.