Euro 550 OBD plug . Yes it is there and I have found it. | Page 6 | FerrariChat

Euro 550 OBD plug . Yes it is there and I have found it.

Discussion in '456/550/575' started by Robbe, Nov 9, 2020.

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  1. franschman

    franschman Formula Junior

    Dec 18, 2017
    349
    Holland
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    Bart
    I'm with you on the bad connection somewhere. But where??? (I know the feeling...)
    Did you check/clean the large round multi pin connectors just behind the cylinder banks? There's 3 of them in a very hot location. If I'm not mistaken the cam phase sensor also passes one of these connectors.
    When I had my engine out I took these plugs apart to clean which was quite necessary.
     
  2. Qavion

    Qavion F1 World Champ
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    Feb 20, 2015
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    Ian Riddell
    Splices are usually hidden by the black plastic sheath around the wiring. Ferrari gives no clues as to where the splices are. The sheath is probably too thick to find the splice by feel. The spices won't be near the ECUs. They will be on the engine side of the firewall/bulkhead as that is where the ECU to ECU interconnect plug is. By the way, "S" is pink in Italian.

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    As you say, you may have disturbed something, but it's going to be difficult to track down what you disturbed. Checking resistances sounds like a good plan.

    I'm not sure I understand your point about the MAF. Fuel pressure regulators are controlled by vacuum. If the vacuum going to the regulator is shut off by a tiny collapsing hose, the MAF is not going to detect this.

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    I can't remember, however, if loss of vacuum causes the car to run rich or cause stumbles or other regulator problems causes this.
     
  3. Robbe

    Robbe Formula Junior

    Aug 22, 2013
    609
    The Netherlands
    Thanks for the informative picture! makes it clear where all parts are going, and will help in measuring.
    @ Bart, I will try to clean the connectors. When I had the plenum out, I did not notice any dirt or corrosion, but something somewhere is not right, so never hurts to try cleaning.

    @ Ian, I reread my posting about vacuum and MAF, and see that I was not clear.
    As far as I know I have no vaccuum problem, as all hoses are checked or replaced. The FPR is controlled by vacuum, but even if this vacuum would be absent, pressure would only rise a few psi, giving a rich mixture, not lean.

    What I meant about the MAF, was that a sudden faulty MAF value should read very low (or high), but on my scanners I see no suspect values.
    When it would be the MAF , I would have seen a drop to like 5 or 100 or so, now it more or less stays the same for both sides when the shut down happens.

    I believe the lean LTFT is because of the shut downs, which the O2 sensor sees, and the ECU tries to compensate by adding extra fuel. But when the injectors are closed, enrichening does give the O2 a better value as no combustion is happening, etc etc.

    Come to think of it,
    Question is, why would the ECU enrichen the mixture when it also decides to close the injectors for a few seconds? Does not make sense

    So maybe the ECU itself does not close it, but a "simple" power loss to the injectors is? (what the ECU does not know)

    Can you agree to this, or is it just grasping straws?
     
  4. Robbe

    Robbe Formula Junior

    Aug 22, 2013
    609
    The Netherlands
    Edit to the above,
    should be: when the injectors are closed, enrichening does NOT give the O2 a better value
     
  5. Timmo

    Timmo Formula Junior

    Aug 26, 2017
    383
    Continental Europe
    Hello,
    Been lurking on here for quite a while but the issues you have been going through are interesting. What colour are the spark plugs? Does the stumbling correspond to a rich running condition? The symptoms you describe correspond to faulty crank sensors but also to failed coolant temp sensor and sometimes failed fuel pressure regulators.
     
  6. Qavion

    Qavion F1 World Champ
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    Thanks for the clarification.

    I still don't understand how the engine runs properly with the scanners fitted. Didn't we determine that some data is shared between the ECUs using the CANbus/OBD2 harness? Because of this, I would expect problems on at least one side because you've disconnected it and are using it for the scanner. Perhaps this is why the relatively good bank is now showing an LTFT change?

    Crossflow engines with sensors on the opposite sides of the engine certainly don't make faultfinding any easier. You need to be constantly aware of what data is going where on the 456M.

    Cam sensor (only one on RH bank/RH side of engine) uses 8 pin interconnect plug to provide data to both banks.
    MAFs (located on same side of engine). This doesn't make sense unless the data is shared on the CAN bus.
    Throttle position sensors (located on opposite sides of engine). They have direct wiring to the correct ECU.
    Inlet air temperature (only one) wired to LH ECU but located on RH side of engine. I guess the data must be shared on the CAN bus?
    Crank sensors (wired directly to their respective ECUs, but located on opposite side of gearbox)
    Coolant temperature sensor (on RH bank only). Data must be shared on CANBus?

    The ECUs have the ability to use data from other sensors if data is lost, so this also has to be taken into account.


    Regarding the wiring checks and the other inter-ECU comms... I guess the resistance checks would be best done between the cam sensor and the ECU as you said that the interconnect plug was very hard to access.

    https://www.ferrarichat.com/forum/posts/147596021/

    As the fault is intermittent, I think these checks would be best done with a second person to shake/flex the harnesses.

    @TTM The crank sensors have already been replaced (although that doesn't not exclude a crank sensor wiring problem). Failed pressure regulators have been known to cause stumbling issues, but as there are problems on both banks, I guess it's not very likely.

    Unfortunately, there are too many possibilities at the moment and I'm not sure how you can reduce the long list without throwing expensive parts at the car (ECUs, fuel pressure regulators, etc...)
     
  7. Robbe

    Robbe Formula Junior

    Aug 22, 2013
    609
    The Netherlands
    Yes, the whole cross-data thing is not helping much at all.
    And if the plugs next to the ECU are necessary, then my 2 scanners are the cause of the wrong mixture, and then show it ironically...
    But: the 50 km trouble free driving immediately after replacing the O2's and cranshaft sensors does not make sense. ( I drove with both attached, to watch the new O2's values which were perfect then)
    What if the car used old data that day to create a working mixture, data like the LTFT? And now has driven 200km with both scanners attached, and the average is now way off because of that?

    But then again, before I switched ECU's it was the left bank shutting down , and after switching it was both banks being affected. An ECU connection issue on top of that? I used Deoxit before, maybe this does not help, but make things worse (dielectric grease properties?), and now I have infected/stained the other ECU as well? Will look into that.

    @TTM, it clearly is 6 cylinders shutting down, not a mixture problem that causes rough combustion on one side. The one moment all is well, the next moment the tone of the engine changes, and no power, O2 values on one side plummet, and a few seconds later the sound changes back again, power is back and all is well up to the next stumble a minute later or so.
    Has not happened at idle (yet) , only while driving.
    When I did the major, all plugs were perfect light coffee + milk colored, textbook examples of good combustion. Leads me to believe that WHEN mixture is allowed into the cylinders, it is perhaps rich for 1 second, but normal after that. Maybe I do another check with the STFT graphs on screen, to see if the ECU tries to compensate the plummet in O2 signal. I suspect it will.

    I suspect that somehow an earth connection or switched earth to the injectors is (part of) the problem.
    As there is fuel, there is fuel pressure, there is fuel flow. LTFT suggests lean and O2 signal of close to 0V when it happens indicates ultra lean (as in no fuel at all).
    I even drove with external 12V to the fuel pump, still stumbled, so it is not the fuel pump part, but the injectors not opening, so no combustion.
    So something must be wrong with 6 injectors not doing what the ECU calculated they should do. What they share is the switched earth, switched by the motronic.
    It is not the harness, checked all resistances, all good, so it must be the wire to the harness that is intermittently faulty, or the ECU itself.
    But why did the car behave itself for one day?

    Ok, so I will do a lot of measuring resistance /continuity again, will ask my lovely assistent to assist in wiggling,, will try to clean the ECU's and connectors to get rid of the Deoxit that still is present on the connectors, and make a test drive without the scanners.
    Will update in a few days (weather must be good enough to drive)
     
  8. Qavion

    Qavion F1 World Champ
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    Perhaps an intermittent ECU internal power supply problem. The O2 sensor elements (not heater), the fuel injectors, the coolant temperature sensor and the throttle position sensors* are powered by the ECU. The rest (coil packs, thermocouple ECUs, idle controllers, cam sensor, etc) are powered by the relays and fuses in the passenger footwell. When you swapped over the ECUs, the fault transferred, but maybe in the new position, the ECU has additional responsibilities (such as sending specific data on the OBD wires to the other ECU). Because the fault transferred it's not likely to be a problem with power being supplied to the ECUs.

    Is there any other data disappearing or going to zero (as recorded by the OBD2 reader on the faulty bank)?

    *the throttle position sensor on the RH side of the engine has two outputs. The output which goes to the Bilstein suspension unit needs power from an external source).
     
  9. Robbe

    Robbe Formula Junior

    Aug 22, 2013
    609
    The Netherlands
    The TPS's on both sides do not show strange values when one bank shuts down, so that should rule out a ECU internal power problem, correct?
    No other data affected, maybe the STFT, have not checked that one. (but raining over here now, so no test drive today)
    By the way, this kind of information is very helpful, as it narrows down the possibilities!
    Any other ECU facts/ info would be really great.

    When I cleaned the left ECU with Deoxit, according to the user manual you should leave the stuff on the contacts, which I did.
    So when I switched the ECU's, it ended up on both sets of contacts.
    Any idea if this deoxit product is a no-go on pin contacts such as ecu's?

    Should I try to open them for further cleaning? I can see that one ECU has been opened before, by the marks on the tabs.
    (the ECU from the non-problematic right hand bank)
     
  10. Qavion

    Qavion F1 World Champ
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    Assuming there are not multiple power supplies in the ECU, it should rule out a power supply issue.

    I can't imagine Deoxit causing any problems on ECU pins. I guess it's a good idea to open up the ECUs to see if there is anything obviously wrong inside such as water contamination. I would use a magnifying glass to look for dry solder joints.... especially where the connector pins are soldered into the circuit board.
     
  11. Robbe

    Robbe Formula Junior

    Aug 22, 2013
    609
    The Netherlands
    I took a look at the already-opened-before ECU, with an eyeloupe, and noticed that some pins have had terrible corrosion in the past.
    I made a mistake in the posting above, this ECU was originally on the troublesome left side, not the right side (I remembered wrongly, but I had marked the ECU's , so I am sure now)
    The Deoxit removed a lot of the corrosion I guess, but now 2 smaller pins have much less surface, more like a moon crater landscape. Maybe this is where the problem is, I still need to look up the numbers and functions of these 2 pins.

    The left connector had some kind of yellow grease in it. I assume to overcome the corrosion connectivity issues.
    I flushed that out with contact spray. The female pins on the connector are all partially opened, so connection is not optimal, thats certain.
    I hope that I can retighten them. A gold SRI kit would be a great idea here...

    I opened up the ECU housing, but that looks really good and clean inside, no corrosion or water ingress or dirt. (does not mean it can't have solder problems, but at least I can't see why it has been opened before, no strange marks inside.) Will take a better look with a 25 times magnifying loupe later on.

    So next thing I will have to do is optimizing the ECU connections, maybe it is all as simple as that...never hurts to hope....will report back coming week.
     
  12. Qavion

    Qavion F1 World Champ
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  13. Robbe

    Robbe Formula Junior

    Aug 22, 2013
    609
    The Netherlands
    #138 Robbe, Apr 11, 2021
    Last edited: Apr 11, 2021
    I had one 550 diagram from you already, the left side, and a different one from the HVAC, so this is very welcome, now I must have everything. (assuming the 550 diagram is similar to these 456 diagrams)
    And understandable, and on one page, and correct. What a difference with the WSM....must have taken you many days to make!

    My worst pins are 56 and 57, one ends up in a 2-wire splice from the coil pack and the other in a dashboard connection.
    Strange, why a splice with only 2 wires, or is it a holder for a fuse or relay?

    I noticed that the switched earth from the injectors is connected to the dashboard connector as well.
    Is this connector a sort of fuse/relay board, or (not likely) is it a sort of splice?
    Just trying to understand what I am seeing...
     
  14. Qavion

    Qavion F1 World Champ
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  15. Qavion

    Qavion F1 World Champ
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    #140 Qavion, Apr 11, 2021
    Last edited: Apr 11, 2021
    Ugh... I think I made a mistake with the fuel injectors. I rechecked and they do get power from the main relay panel. The earth isn't switched, it's the power. Not sure how I made that mistake. The RN wires are very distinct on the 550 and the 456M.

    Not sure. Maybe the harness would be too difficult to run if there wasn't a splice there. I've seen it on other Ferraris and asked myself the same question. On some cars, additional connections to splices are shown in other diagrams.

    Yes, each diagram takes many days and they are improved and corrected over a much longer period.
     
  16. Robbe

    Robbe Formula Junior

    Aug 22, 2013
    609
    The Netherlands
    Thanks again Ian for all these diagrams, very kind to share them. Invaluable.

    About the injectors, I mentioned switched earth because I read that somewhere: there was supposed to be always 12V on them, and the motronic would switch on earth. Not sure where I read it (have read a lot...) but it sounded logical to me. I did not check however if it is true, about the always 12V.
    So if this is not true (and the diagram RN wire sure is not switched seperately for the injectors) , I may have confused you, not the other way around...
     
  17. Qavion

    Qavion F1 World Champ
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    #142 Qavion, Apr 12, 2021
    Last edited: Apr 12, 2021
    I see what you mean. I wasn't sure what you meant by "switched". Yes, the ECU has to turn on the injectors individually with an earth.

    The ECU does control the power to the injectors, too, but once the ECU's have gone through their quick "health checks" when the ignition key is turned to ON, the ECUs turn on the injector power via the passenger footwell relays "O" and "B". A grey-yellow wire on ECU pin 27 supplies an earth to the respective relay coil.
     
  18. Robbe

    Robbe Formula Junior

    Aug 22, 2013
    609
    The Netherlands
    Ok, so the RN wire is a 12V wire?
    Is it a safe assumption to say that if the ECU itself (in case of solid SDL etc) shuts down a bank, it just shuts down power on the RN wire?
    So the injection relay is shut down and all injectors are without 12V?

    And if shutting down, in my case, happens by accident, there is a fair chance something in the RN wire is not ok, for instance a loose connector making intermittent contact?
    As swapping the ECU's resulted in both sides being affected, maybe pin 27 not being ok, opening up now both of the harness connectors too much? Or maybe that grease that I found, actually insulating the pins instead of protecting?

    The splice itself on top of the diagram is not likely to be a problem I think, but maybe the "dashboard connection" is? Any idea where to find that one in the car ? In the footwell, or deeply hidden in the dashboard...

    Just trying to think of a direction to seek the problem in.
    I am not a mechanic and obviously not an engineer, so it might be that my questions show this :)
     
  19. Qavion

    Qavion F1 World Champ
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    If the ECU killed those relays, you would lose more than just the injectors, but the fuel pump, cam sensor, thermocouple ECU, idle speed regulator, MAF, O2 sensor heating and the exhaust manifold compensation valve. I think SDLs are more subtle than that. If there was a problem with only the RN wire, then it would only affect the injectors ... and the "modular manifold solenoid valve" (whatever that is :p).

    Not sure. It may be in the same location as the equivalent on the 456M's 17D (for the Right bank)

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    For the Left Bank, the 456M's 23F:

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    They seem to be fairly close to the ECUs in the footwell side panels. It should be easy to find if you trace the wiring from the ECU.

    I really don't know what to do next either. I guess this is where a Ferrari mechanic's experience comes in handy... although you may have a unique problem here.
     
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  20. Robbe

    Robbe Formula Junior

    Aug 22, 2013
    609
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    Thanks anyway for the new diagrams, it at least makes me understand the car a little better, and röntgenview is always handy.

    On the left ECU , a connector is bolted normally using the same upper stud and nut als the ECU. To remove the ECU, one has to remove and bend away that larger connector. On the right side, there is even more bolted on top.
    I will take a look at those connectors, maybe it is the "dashboard connector"/17D/23F. And bending it away caused a loose connection? Never hurts to check anyway.
     
  21. Robbe

    Robbe Formula Junior

    Aug 22, 2013
    609
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    The "dashboard connection" is indeed the 21 pin connection , one bolted on top of each ECU.
    I took mine apart, slight signs of corrosion on the pins but not much, but soaked everything in Deoxit anyway, and will wash them out tomorrow with contact cleaner.

    here is a picture for future reference.
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    And to show I really have no idea about electronics,
    I noticed that half of the colors go through the connector (in and out same color), but some colors "end" and change color on the other side...
    I thought that was strange, but I am sure it is original that way.
     
  22. Qavion

    Qavion F1 World Champ
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    Thanks for the photo. I see you've solved Bart's (@franschman) problem of how to get into those connectors, by pulling on the yellow tab (or did he tell you?)

    I'll add a note to my diagrams with the location of the dashboard connections.

    Cheers (and good luck)
     
  23. Robbe

    Robbe Formula Junior

    Aug 22, 2013
    609
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    To be honest, I spent 5 minutes trying to open it. I pulled the yellow tab half a cm out, thinking it would unlock it, then tried to push in 4 tabs on the long sides.
    Every time I had done one side and switched to the other, the first would click back in. Came to the conclusion it was not the way.
    Pulled a little harder on the yellow tab, only to find out it is a gliding system: pulling out the tab further after the resistance I felt, it would glide apart.
    The other side was opened in 2 seconds...very handy system if you know what is required....
     
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  24. belfry

    belfry Formula Junior

    May 14, 2015
    390
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    Robert Batt
    I have just bought a similar cable for my 456. What vehicle did you tell the Autel scanner that it was connected to please? Did you need to pretend that it was a particular Fiat model?

    Many thanks

    Belfry
     
  25. Qavion

    Qavion F1 World Champ
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    Sorry, just noticed your comment. Yes, this is quite common, especially if it relates to a vehicle system carried over to another model.

    The Fiat plug adaptor just directs the 3 wires to the correct pins on the OBD2 plug. It's not vehicle- or company- specific. You should get all the codes you need from a car of this era. A cheap scanner, however, will not provide accurate descriptions of what the codes mean (unless it is a generic P0xxx code). The same (non-P0xxx) code can mean different things on even different model Ferraris.

    I use a cheap scanner with BMW or Audi selected for my F355. It seemed to offer a better code description, but was wrong from time to time. The scanner will give you the codes, but you will still need a proper Ferrari code decoder. I don't know if anyone has a decoder for the 456M or 550? @tazandjan
     

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