2010 599 p0721 output speed sensot | FerrariChat

2010 599 p0721 output speed sensot

Discussion in 'Technical Q&A' started by angsel1, Jul 25, 2023.

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  1. angsel1

    angsel1 Rookie

    Nov 18, 2015
    8
    Lake elsinore ca
    Full Name:
    A fallara
    Hello, I have an intermittent P0721 output speed sensor code coming up in my 2010, 599. Can anybody point in the right direction as to which sensor this is and or where it is located appreciate any advice. It only happens once in a while no specific conditions, been looking through the diagrams on scuderia etc. and cannot find an output speed sensor on the transmission. No engine codes no ABS codes just the P0721 in the trans and it gives me a failure warning restart it and it’s gone. don’t want to spend thousands at the dealer if I don’t need to thanks for any help
     
  2. Qavion

    Qavion F1 World Champ
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    Feb 20, 2015
    13,921
    Sydney
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    Ian Riddell
    Wild guess.... no experience on this car... Item 39?

    https://www.eurospares.co.uk/Ferrari/599/599_GTB_Fiorano_(USA)/PartDiagrams/0025/GEARBOX_HOUSING

    Seems to be the same part number as on the F355, 360, F430, 575, 612, Enzo .... and seems to serve the same function #168729

    https://www.ricambiamerica.com/168729-sensor.html

    I assume you have an F1 gearbox

    Looks like it is in line with the gearbox drain plug (on the rhs of the gearbox)
     
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  3. Qavion

    Qavion F1 World Champ
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    Feb 20, 2015
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    According to the F355 manual, it's a Hall Effect sensor. On the plug, there should be 3 pins:

    Power (12 volts I believe, from the TCU)
    Earth (chassis)
    Signal to TCU

    As there are electronics in the sensor, they may be affected by heat. You might get lucky with a sensor change (alone). Not that they are cheap (if you can find one).
     
  4. angsel1

    angsel1 Rookie

    Nov 18, 2015
    8
    Lake elsinore ca
    Full Name:
    A fallara
    I took the same guess but when I unplug that sensor I get an input speed sensor code not the P0 721 or an output speed sensor. Also when I unplug it and ran it soon is it through that code it shut down the engine on me which that’s not what’s happening, thanks for the reply though. I appreciate any insight somebody may have.
     
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  5. angsel1

    angsel1 Rookie

    Nov 18, 2015
    8
    Lake elsinore ca
    Full Name:
    A fallara
    Yes, it is an F1. Thank you for the information. I’m trying to figure out where the sensor is located or what sensor will throw that code
     
  6. Qavion

    Qavion F1 World Champ
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    Feb 20, 2015
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    There is a range of generic OBD2 codes relating to the output speed sensor with each code showing a different type of problem (P0720 ~ P0723).

    e.g. P0722 incorrect or irrational input signal from the transmission's output speed sensor.

    It's still possible that the sensor or sensor wiring is causing issues.
     
  7. angsel1

    angsel1 Rookie

    Nov 18, 2015
    8
    Lake elsinore ca
    Full Name:
    A fallara
    Any idea where that sensor is located?
     
  8. Qavion

    Qavion F1 World Champ
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    It's the one you unplugged.

    You generated a different code by unplugging it completely. My point was that it may have a defect which is not the same as unplugging it. Intermittent is not the same as completely inoperative.
     
  9. angsel1

    angsel1 Rookie

    Nov 18, 2015
    8
    Lake elsinore ca
    Full Name:
    A fallara
    When I unplugged it, it said input speed sensor fault not output. I have a Texa coming in a couple of weeks. Hopefully that will help. Thanks for the reply
     
  10. Qavion

    Qavion F1 World Champ
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    Feb 20, 2015
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    When I Googled the generic P0722, it had the description I said above:

    The words input and output are both used. Your scanner may be simplifying the description. The new scanner may also do the same.
     
  11. angsel1

    angsel1 Rookie

    Nov 18, 2015
    8
    Lake elsinore ca
    Full Name:
    A fallara
     
  12. angsel1

    angsel1 Rookie

    Nov 18, 2015
    8
    Lake elsinore ca
    Full Name:
    A fallara
    I agree with you I’m using a Chinese tool now the Texta is an Italian tool and hopefully it will clarify if not, I will just go ahead and try replacing that sensor first and see if it solves the problem but it’s interesting because it’s a momentary glitch. If you weren’t watching, you wouldn’t even know that it happened . It has no effect on the car Driving wise and it just goes on and off for a split second and leaves that code
     
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  13. Qavion

    Qavion F1 World Champ
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    Feb 20, 2015
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    I think you've made the right decision to change the sensor. Intermittent faults can be hard to reproduce.

    I don't have any wiring diagrams for the 599, so I can't be sure which pins on the TCU plug correspond to the pins on the sensor plug. If the problem persists after the sensor change, maybe you could figure out which is the power wire and give the plugs and wiring harness a shake to see if the voltage disappears.
     
  14. angsel1

    angsel1 Rookie

    Nov 18, 2015
    8
    Lake elsinore ca
    Full Name:
    A fallara
    Thanks for all your input. It’s much appreciated. I will post back when I knew more.
     
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  15. Ollie599

    Ollie599 Rookie

    Apr 2, 2023
    3
    Were you able to solve this problem and how? I am facing the same issue with my 599GTB
     
  16. Gary_LIN

    Gary_LIN Rookie

    Apr 16, 2024
    2
    Full Name:
    GaryLIN
    My guess is that part 168729 is faulty.

    I also encountered the same problem
     
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