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Ferrari 550 Wiring Diagram Confusion

Discussion in '456/550/575' started by Qavion, Jul 13, 2019.

  1. Qavion

    Qavion F1 Rookie

    Feb 20, 2015
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    Ian Riddell
    I'm just wondering if anyone has battled with the Ferrari 550 wiring diagrams? I've been trying to create coloured diagrams which are easy to read. I found a workshop manual online and have been trying to make sense of diagrams. I've run into several problems. e.g.

    Fuse and relay numbering/lettering on diagrams do not match the car.
    Wire colours on diagram do not match the car
    Different wire colour codes on the same wire in different diagrams.
    Component List does not match the diagrams (e.g. the left engine diagram has right engine component numbers, electrical component symbols do not match the component list identification, missing components, etc.
    WSM pages missing.
    Italian "english"

    I've sorted out many of the problems, but it's been slow going as I don't have a Motronics ECU pinout.

    My current problem is with the ignition switch:
    Diagram wire colours do not match the car's.
    It's not wired up how I expect it to be in some diagrams.
    The WSM shows the ignition switch has 3 positions: OFF, POS II, START. The wiring diagrams show four positions: OFF, POS I, POS II and START.

    e.g. Does the car have a (mechanical) POS I (like an "accessory" position) and do the headlights work in that position? I don't have access to a 550.
    Perhaps POS I and POS II are jumpered (shorted)?

    Thanks!
    Cheers
    /Ian

    P.S. Here is a sample of what I'm trying to do:

    Ferrari550/Ferrari_550_Engine_Service_&_HVAC Wiring Diagram v1

    P.P.S. I duplicated this post on the Tech forum by mistake
     
  2. Qavion

    Qavion F1 Rookie

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    Here's how the manual shows the ignition switch with varying colours on the accy position and my version, showing the actual colours seen in online photos of the lock assembly.

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    G = yellow
    GN = yellow with black stripe
    A = light plug
    AN = light blue with black stripe
     
  3. Jake9713

    Jake9713 Rookie

    Feb 1, 2019
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    Jake Hatfield
    I am in the same boat on mine, I really need the HVAC wiring diagram for this car on the opposite side of #275, basically from the dashboard connector to the Diavia system and HVAC control unit. I am chasing a problem, and there is nothing but a vague diagram in the WSM, I don't know why its not there, maybe because its on Diavia? Very frustrating
     
  4. Qavion

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    #4 Qavion, Jul 19, 2019
    Last edited: Jul 19, 2019
    I tried to figure out the circuit, but as you say, there is just a vague diagram. Only 7 pins are labelled on the Diavia. I don't know how long the cable is between 275 and the Diavia, but I was able to trace a few of the wires between them using the wiring diagrams and WSM.

    Here's my HVAC diagram (2nd version):

    550 HVAC diagram

    ...and here's some random notes on the HVAC /Diavia that I compiled from the WSM and wiring diagrams after some marathon headscratching today:

    Random HVAC notes

    I assume the Diavia ECU has 18 pins?

    It was made more difficult, because the two min/max pressure switches aren't labelled... and the WSM mentions three pressures.

    A fellow FChatter provided me with some clues on the ignition lock. There is a detent at the accessory position, but it has no visible/audible effects. I guess the yellow wire in the diagram is hooked up to the RUN position, not the ACCY position (I need someone to stick their head under the steering column to see if the light blue (only) wire has a corresponding two wires (yellow and yellow black)).
     
  5. Jake9713

    Jake9713 Rookie

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    Thank you for taking the time to whip up these diagrams, you make life easier this is super helpful. My ignition switch connector has been modified, I actually crimped a weatherpack style one on unfortunately, my car was a hurricane claimed flood vehicle. I snapped a picture of the ignition switch wiring colors on my Nov built 97 (98 model) 550 Maranello Pininfarina. Original wire colors, just new connector see below. I will also respond with my pictures of the HVAC control unit connector, my 275 connector, and the Daivia A/C ECU.
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  6. Jake9713

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  7. Jake9713

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  8. Qavion

    Qavion F1 Rookie

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    Thanks! That should keep me busy for a weekend.

    Looks like those wire colours match my current diagram. It's a pity we can't see the colours on the other side of the plug, particularly the one which corresponds to the light blue/black wire.

    Just to confirm, the wire colours shown are the ones which go to the HVAC unit? I see some wire colour changes on different sides of the plug (not unusual).
    Some of the colours I can't quite make out:

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    Pin 1 looks like brown black, but it may be brown green to match up with the opposite side of the plug.
    Pin 12 looks like violet brown, but may be violet yellow to match up with the opposite side (perhaps a dirty yellow?)

    Thankfully you reversed the plug. Some of the stripes are completely hidden from one side.


    Some of the wires seem to go to different positions, too. I had a look at the 360 diagrams. I was thinking that the 550 may have been a match to that. I'll see if I can get a match to your photos, but there are lots of same colour wire which may be hard to distinguish.

    That explains the rusty nuts. Looks like we're going to be busy for the next few months :D
     
  9. Qavion

    Qavion F1 Rookie

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  10. Qavion

    Qavion F1 Rookie

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    Regarding the ECU white plug wiring in the photo, there seemed to be lots of indistinguishable grey, green and blue wires making pin matching impossible. Looking at the 360 diagrams, the colours and pins didn't seem to match either, but then I flipped and rotated the plug numbering and there was a really good correlation.

    This is my best guestimate:

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    I always show the plugs as viewed from the front of the plug, not where the wires go in the back, so you will have to mentally flip the plugs to match the photographs.

    Unfortunately, my technique didn't work for the "A" plug on the ECU. Unfortunately, the "A" (yellow) plug has one of those horrible backshells which hide the wiring and make it difficult to remove the plug.
     
  11. Jake9713

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  12. Jake9713

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  13. Qavion

    Qavion F1 Rookie

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    Thanks! Looks like I've made a few mistakes. I'll fix them up tomorrow.

    The wiring on your fried ignition plug was easy to identify, but it suggests that the electrical system is active in the accessory position, contrary to the car's behaviour. Maybe the yellow wire doesn't go anywhere.

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    2am here.. and still trying to sort out diagrams... I must be crazy )
     
  14. Qavion

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    Looks like my guesswork was close, but I'm still having trouble identifying the same wires on ECU plug B... see magenta dots.

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    I think pin 6 is blue-black and I'm hoping 9 is red-black. Pin 3 may be grey-black.
     
  15. 308 GTB

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    No, just dedicated. :)
     
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  16. Qavion

    Qavion F1 Rookie

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    #17 Qavion, Jul 20, 2019
    Last edited: Jul 20, 2019
    I'm just wondering what that white/translucent 2-pin connector is in the photo below (near the ECU yellow plug).

    A grey wire (with red or brown stripe) goes from ECU connector B (between your fingers) below) to this 2 pin connector. Does the other grey wire also go to that connector B? It seems to go in the wrong direction, but may double back. Can you confirm the colours on that plug please?

    Perhaps the Treated & Mixed Air Temperature Sensor on the Distribution Motor?


    This will be another key to the HVAC puzzle.

    Unfortunately, I didn't have much luck matching the wires on plug 275 and the rest of the diavia system. There are too many wires which seem to have the same colour. Also, the function of the ECU pins shown in the WSM did not match the wiring diagram colours on plug 275.

    Random notes part 2...

    Maranello_Random_HVAC_Note Part 2.gif
     

    Attached Files:

  17. Qavion

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    Jake , I believe that device with the green and white wires (and rusty bolt) next to HVAC ECU is the "TGK Valve". It has green and white wires on one side of its connector, but it would be good to know the colours of the wires on the other side of the connector. I believe it is hooked up to the HVAC ECU.

    See post 13...
    https://www.ferrarichat.com/forum/posts/146720309/

    The TGK valve meters hot water into the system for heating. A pulsed signal from the ECU controls it.
     
  18. Jake9713

    Jake9713 Rookie

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    Sorry for the late reply. I am in the states, Saturday has been hectic in the shop. I crawled under the car and done a color confirmation on the Diavia ECU and done a fast MS Paint edit to your GIF file, I can confirm my text edits are the true color of the pins you had in question. I believe you are correct in the TGK Valve, see below. If you need 275 color confirmation as well I can do that.

    Also, in regards to the two pin connector you had mentioned, one pin is gray/red which goes to the Diavia ECU B pin 1, the other wire on the two pin connector is solid gray, and does not go to the Diavia ECU, it seems to snake back into the main A/C harness possibly to the 275 or another component?
    Again, really appreciate the work and involvement you are giving. Thank you
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  19. Jake9713

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  20. Qavion

    Qavion F1 Rookie

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    #21 Qavion, Jul 21, 2019
    Last edited: Jul 21, 2019
    No problem. I understand how tedious wiring checks are. Frustratingly, not much progress was made.

    The following data available on 275 has to go to the ECU, but there are no corresponding colours on the ECU:
    Right bank coolant temperature
    Radiator fan control
    Outside air temperature
    Ignition power (pin 9). There may be a splice with a colour change before it reaches pin 3 on the ECU. That power also needs to go to the control panel (pin 3)

    Could some of your colour confirmations have reversed colours. Maybe the stripe is not the stripe, but the main colour? Particularly white-orange and white-green.

    wires still to match:
    8 on 275 (most functions known)
    17 on ECU plug A, possibly 19
    5 on ECU plug B (all functions unknown)
    3 on control panel (all functions known)

    We may have to resort to continuity checks, but I'll try to make a list of sensors and motors. Hopefully if access is easy to these, we can check their wire colours.

    Does this plug go to the TGK valve or elsewhere?

    I heard a rumour that the 575 has very similar wiring, but better schematics. Is there one available online?

    Here's an updated diagram using your confirmed colours:

    Random Notes v4
     
  21. Qavion

    Qavion F1 Rookie

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    Here's an updated HVAC diagram

    Engine Service & HVAC/Diavia Wiring Diagram version 4

    I was orginally trying to fit everything into one diagram, but I may run out of room.

    Would you be able to do a continuity check to see if either pin 8 or 5 on connector 275 goes to pin 7 on connector B of the ECU (yellow only wire)? This will enable me to hook up at least one extra wire. Pin 8 is on one end of the plug, pin 5 is next to the clip.
     
  22. Qavion

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    Wiring known

    "Emergency fan" relay controlled by the Motronics ECU
    compressor solenoid
    sun radiation sensor
    electric water pump (runs continuously)

    Unknown Wiring

    Cabin air temperature sensor
    TGK proportional valve
    Distribution motor (lhs)
    Treated and mixed air temperature sensor (lhs)
    Right recirc motor
    left recirc motor
    diagnosis socket rhs
    solenoid valve adjuster (?) (two plugs)
    Electric fan
    pins on min/max pressure switch (4 pin AC pressure switch on dehydrator filter (P/N 66374400))
     
  23. Jake9713

    Jake9713 Rookie

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    I can't seem to locate a single wiring diagram for the 575, from the forums I have read people are suggesting using the 550 diagrams as they are more documented.

    The two pin does seem to go to the TGK valve.

    Pin 5 on connector 275, yellow does NOT have continuity to ECU B pin 7.
    Pin 7 on connector 275 DOES have continuity to ECU B pin 7. It seems that the color changes to from white/orange stripe on 275, to yellow on the A/C ECU.

    I will try to devote a weekend to continuity checking 275 back to the ECU, on all further pins to help out. I just wish someone already had the documentation for this, it has to be out there. It would save us all the trouble! What does Ferrari do when they have to diagnose one, just replace harness? Ha! Battling the fuel sending unit as well, circuitry seems to go from the secondary gauge to the Main gauge, then to the Information Center DIGITEK unit, then to the fuel tank... sigh... wish I knew the ohm range of the fuel sender. We do not have a fuel tank, previous owner removed... and are trying to fab a custom one, and sending unit. This project has been an adventure to say the lightest
     
  24. Qavion

    Qavion F1 Rookie

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    #25 Qavion, Jul 25, 2019
    Last edited: Jul 25, 2019
    Strange... I just discovered from photos that the TGK Valve has a 5 pin plug.

    Unfortunately, the wiring on the components themselves don't always tell us its corresponding harness wire colours.

    Ugh... I can add a splice to my diagram. It could get more complicated than we imagined though. I just noticed there is a relay in the parts manual which doesn't appear on any of the diagrams.

    I recall reading somewhere that for several hundred dollars, you can access the Ferrari wiring database for a day. I'd be worried though that you'd end up with the same diagrams in the WSM. The proper paper diagrams will set you back thousands. I've seen some of them for the F355. It took me about 4 years of looking to find the details I needed to complete the engine management diagram. Hope you're patient ))))

    I spent most of a day trying to understand the fan wiring and coolant temperature circuits. There are three coolant temperature sensors. The one on the left bank feeds its respective Motronics ECU. The ECU then transmits the signal to the L/R Bank Interconnect plug and the signal come out of the right bank connector to the emergency relay. If the HVAC-controller fails to turn on the fans, the Left ECU turns them on at a slightly higher temperature than normal.

    Makes sense. There is probably just a wire splice inside the DIGITEK(?) unit before the signal is digitized. Both the main gauge and secondary are getting the same analog signal from the sender. I'll add that to my diagram. Sorry, I'm not totally familiar with F550 terms. You mean the main instrument panel magic box which turns analog signals to digital displays?
    Since there is no wire on the low fuel level switch on the sender, the low fuel warning must be computed from quantity values.

    Random HVAC notes #8
     

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