Volvo MDI unit failures on D" series engines

Playtime

Well-Known Member
Joined
29 Jan 2007
Messages
1,194
Location
Chichester
Visit site
There are a few reports on another forum (Hanse Owners) of MDI units failing. This is the electronic box that supports the engine sensors, functions and alarms (start, stop, revs, temperature, oil pressure and NMEA2000 interface) on Volvo D2 series engines. The failures have resulted in the engine stopping unexpectedly and/or failing to start when required.

Has anyone on this forum directly experienced or heard reports of similar MDI failures?
 
We had an early failure of an MDI on a replacement D1-20. The problem seems to have been caused by the starter motor which also had to be replaced.
All done under the warantee thank goodness.
 
When you posted on the Hanse forum about your experience of the engine not starting, you later reported that you'd found an earth connection wiring fault, and that it wasn't an MDI issue. Has this situation changed?
 
There are a few reports on another forum (Hanse Owners) of MDI units failing. This is the electronic box that supports the engine sensors, functions and alarms (start, stop, revs, temperature, oil pressure and NMEA2000 interface) on Volvo D2 series engines. The failures have resulted in the engine stopping unexpectedly and/or failing to start when required.

Has anyone on this forum directly experienced or heard reports of similar MDI failures?

There was an X Yacht just down the pontoon here in La Linea, less than 12 months old. His failed, stopped the donk starting. When I got in to it for him it turns out that basically it is just an interface to allow engine data to be squirted out to the MMEA 2000 bus. It doesn't actually do any engine controlling. Apparently there is a relay in there that fails, The local VP agent knew all about it. The relay not latching stops the start circuit working. You can frig it at the solenoid which they hide behind a cover on the starter
Stu
 
When you posted on the Hanse forum about your experience of the engine not starting, you later reported that you'd found an earth connection wiring fault, and that it wasn't an MDI issue. Has this situation changed?
If you read the Hanse thread referenced in the first post you can deduce that the answer is no! However several others have reported 'real' MDI failures
 
. . . . It doesn't actually do any engine controlling. Apparently there is a relay in there that fails, The local VP agent knew all about it. The relay not latching stops the start circuit working. You can frig it at the solenoid which they hide behind a cover on the starter
Stu

The MDI interfaces with the cockpit panel to control starting and stopping and display revs and alarms. There are also semiconductor relays in the unit that interface to the starter solenoid, glow-plugs and stop solenoid.

You are correct that it doesn't control the actual running of the engine i.e. it is not like an engine management system that you find on modern cars etc.
 
Yes, common problem (over the last 12/18 months). They must have had quite a large duff batch. Most are replaced under warranty. If you have to buy a new one they are extortionate and have no user serviceable parts inside.

You need to know how to start (and stop) independently - long screw driver works a treat. If you are unsure - speak to a Volvo dealer - they all know the issues, most are keeping their heads down.

I have heard some dealers have installed the old style relay box, with real relays, instead. Though not sure how warranty works with this arrangement.

Jonathan
 
Unfortunately a sign of the times. Replace a box with replaceable elements with a cheaper to produce box with everything integrated.

On cars there are now at least 6 mini computers/micro processors (one in each corner for lights, one for steering wheel controls, one for dashboard and another for engine) and in fairness considering the number failures are relatively rare.
 
Yes, I had this problem with the D2-40 I had installed last year. Engine kept stopping/not starting. Engineer changed the mdi box but it made no difference. After a lot of tooing and froing it turned out it was the stop solenoid which he changed. He also changed the mdi unit, in case that had been affected, and I have since had 200+ trouble free hours of motoring.

Apparently Volvo are aware of this, but seem reluctant to admit it publicly. This seems a ridiculous policy, because even if I go on to have thousands of trouble free hours, I will always say " ah, but in the beginning........". At least it was under warranty, or I would have been really pissed off instead of quite pissed off!
 
I believe the box is standard, or identical, on all the 'D' series engines, from smallest to biggest. If you ring your Volvo service agent and tell him your engine appears 'dead' - its such a commonplace issue now they will immediately assume its the relay box, as long as the engine is of the right vintage. There was a delay in Oz for replacement units - but this should have been overcome by now.

Jonathan
 
The MDI interfaces with the cockpit panel to control starting and stopping and display revs and alarms. There are also semiconductor relays in the unit that interface to the starter solenoid, glow-plugs and stop solenoid.

You are correct that it doesn't control the actual running of the engine i.e. it is not like an engine management system that you find on modern cars etc.

Thats what I said :)
Stu
 
Thats what I said :)
Stu

Not quite. What you actually said was "When I got in to it for him it turns out that basically it is just an interface to allow engine data to be squirted out to the MMEA 2000 bus. It doesn't actually do any engine controlling."

OK, I was being a bit pedantic but I would consider starting, stopping and activating the glow plugs to be "engine controlling". Also interfacing to the engine control panel in the cockpit I would consider to be more than "just an interface to allow engine data to be squirted out to the MMEA 2000 bus", although that is one of its (little used) functions.

Apart from that, we are in agreement.
 
Has anyone on this forum directly experienced or heard reports of similar MDI failures?

The answer appears to be yes and Volvo apparently are aware of the problem but are not doing much about it. I find this disturbing; the MDI is effectively a vital piece of safety equipment as it directly controls starting and stopping of the engine. If engines are failing to start when needed or stopping unexpectedly (and failing to restart), possibly in dangerous situations, then this is serious.

I wonder if any such failure has resulted in an accident?
 
The answer appears to be yes and Volvo apparently are aware of the problem but are not doing much about it. I find this disturbing; the MDI is effectively a vital piece of safety equipment as it directly controls starting and stopping of the engine. If engines are failing to start when needed or stopping unexpectedly (and failing to restart), possibly in dangerous situations, then this is serious.

I wonder if any such failure has resulted in an accident?
It is serious stuff but I have noticed that all of these big conglomerates ignore you if it suits them. Another example is the BMW swirl plate issue.
We are little people!
Stu
 
The answer appears to be yes and Volvo apparently are aware of the problem but are not doing much about it. I find this disturbing; the MDI is effectively a vital piece of safety equipment as it directly controls starting and stopping of the engine. If engines are failing to start when needed or stopping unexpectedly (and failing to restart), possibly in dangerous situations, then this is serious.

I wonder if any such failure has resulted in an accident?
The guy I told you about had some serious crew on board, he was in Ceuta across the straits. The donk wouldnt start so they decided to sail back. They sailed it out of Ceuta off the pontoon, across the Straits and in to La Linea on to their pontoon. We spotted him gently sailing down the middle of the marina and went to help him berth, he didnt need any! He spilled and sheeted perfectly.
S
 
It is serious stuff but I have noticed that all of these big conglomerates ignore you if it suits them. Another example is the BMW swirl plate issue.
We are little people!
Stu

Agreed.

The guy I told you about had some serious crew on board, he was in Ceuta across the straits. The donk wouldnt start so they decided to sail back. They sailed it out of Ceuta off the pontoon, across the Straits and in to La Linea on to their pontoon. We spotted him gently sailing down the middle of the marina and went to help him berth, he didnt need any! He spilled and sheeted perfectly.
S

He did well but there are situations where an engine greatly increases the safety margin for 'average' or short-handed sailors - lee shore, lack of wind, adverse tide, big ship with no time or space to manoeuvre etc.

[FONT=&quot]Most sailors want to trust their engine to work without problem when required.

It's disappointing when tried and trusted simple manual/mechanical systems on a boat are replaced by complex electronic systems that may be unreliable and un-repairable. I know, it's called progress but is it what sensible sailors actually want?

[/FONT]
 
Agreed.



He did well but there are situations where an engine greatly increases the safety margin for 'average' or short-handed sailors - lee shore, lack of wind, adverse tide, big ship with no time or space to manoeuvre etc.

[FONT="]Most sailors want to trust their engine to work without problem when required.

It's disappointing when tried and trusted simple manual/mechanical systems on a boat are replaced by complex electronic systems that may be unreliable and un-repairable. I know, it's called progress but is it what sensible sailors actually want?

[/FONT]

Indeed, and what scares me even more is the common rail engines we are being forced to use in the future. Not so much the concept but the electronics. If VP cant get a simple electronic basic relay system right then what chance for a system that actually controls the injection etc? I made a comment on another post about connections going to be the prob but on the evidence coming forward, phew! I pop in to the mobo forum now and again, they have this stuff already and I see issues arising there. We see issues arising on early era mid 2000 cars with main dealers having to be involved, what happens in the future when AWBs become MABs what chance for PBOers then?
Stu
 
Top