355 F1 Shifting Problem | FerrariChat

355 F1 Shifting Problem

Discussion in 'Technical Q&A' started by Mel Spillman, Sep 11, 2020.

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  1. Mel Spillman

    Mel Spillman Formula Junior
    Silver Subscribed

    Nov 3, 2012
    635
    Sugar Land, Tx
    Having shifting problems on my 355 F1. First, while driving the gear indicator light would sometimes flash and when downshifting from 6 to 5 it defaults to neutral. No codes showed up. Leonardo shows pressures are good but will not do a cycle test. Goes through all gears manually with the Leonardo. Sometimes would hear a moaning sound from pump, like it's trying to apply more pressure, though the Leonardo is showing 59 bar. Pump never seems to bleed down. Any suggestions ?
     
  2. Qavion

    Qavion F1 World Champ
    Silver Subscribed

    Feb 20, 2015
    11,484
    Sydney
    Full Name:
    Ian Riddell
    If the pump is running continuously, perhaps you have a faulty Power Unit pressure sensor? I don't know how this would cause a flashing light though. Possibly two problems?

    Here's a wiring diagram which includes the wiring going to the pressure sensor.

    Fig12a F355 F1 Wiring Schematic

    green/white wire = 5 volts power from TCU (ECU)
    violet/white wire = earth
    pink/black wire = pressure output to TCU.
     
  3. Mel Spillman

    Mel Spillman Formula Junior
    Silver Subscribed

    Nov 3, 2012
    635
    Sugar Land, Tx
    Thanks for your reply. The pump does not run continuously. The system actually never looses pressure. That is what is so weird. Even when you start the car when cold, the pump only runs for 2-3 seconds. Again, Thanks
     
  4. tazandjan

    tazandjan Three Time F1 World Champ
    Lifetime Rossa Owner

    Jul 19, 2008
    37,984
    Clarksville, Tennessee
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    Terry H Phillips
    Mel- You need to get someone who knows the F1 system and the Leonardo to analyze the problem. First would likely be a fluid change and bleed and see if she will self-test then.
     
  5. taz355

    taz355 F1 Veteran
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    Feb 18, 2008
    5,942
    Indio Ca/ Alberta
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    Grant
    If it is a stock pump and it only runs for 2 or 3 seconds how many gears will it shift when engine is OFF before pump kicks in again.
    A good pump and pressure tank will usually shift from first to second but when you hit third it will kick in again.
    Sometimes it will hit fourth before kicking in but 9 times out of ten kicks in in 3rd.

    what does yours do and when it kicks in , and for how long?
     
  6. Mel Spillman

    Mel Spillman Formula Junior
    Silver Subscribed

    Nov 3, 2012
    635
    Sugar Land, Tx
    Thanks for your reply, It shifts twice before it recharges, on the third shift, it recharges. The thing I don't understand is it will hold pressure overnight where most of them bleed down overnight. i can sometimes come in the next day, turn the key on and the pump does not run because it has enough pressure in the system. To me, that's strange. Thanks again for your help.
     
  7. windsock

    windsock Formula 3
    Rossa Subscribed

    Nov 29, 2006
    1,066
    Your description either sounds like a failed accumulator or you have a position potentiometer failing. These systems will not hold pressure overnight, if your pump is only running a few seconds that is a very common sign of accumulator failure, those are an easy replacement and readily available.
     
  8. taz355

    taz355 F1 Veteran
    Owner Silver Subscribed

    Feb 18, 2008
    5,942
    Indio Ca/ Alberta
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    Grant
    It seems like pump is likely ok, for now.
    Start on the mechanical side

    all checks with power on, engine off
    check to ensure that the mechanical linkage has clearance underneath, ie the engine mounts are not sagging
    Also have someone sit in the car while you watch the shifter from underneath while shifting, it should shift through all gears cleanly.
    If this is ok now you should check other things the system relies on
    Speedometer has to be working with no intermittent signals, this will cause the transmission light to flash
    You said it sometimes shifts to neutral while going 6 to 5. What about other gears, did you hit a bump when this happens as the system also has electrical to the doors, front and rear bonnet which will cause car to go to neutral when ever it would get a faulty signal, ie from a bump or jar.

    still do not really have enough info but when gear indicator flashes does the transmission light also flash, and for how long, ie very briefly or for a few seconds before resetting??

    when it does go into neutral fro a 6 to 5 shift, does it immediately start working again,.

    is it only in those gears?

    have you read about the system in the workshop manual so you understand what other systems the f1 relies on while operating.
    This will really help you understand what else it sees and might help you give better details on what system may be giving an intermittent signal.
     
  9. taz355

    taz355 F1 Veteran
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    Feb 18, 2008
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    Grant
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    this shows all the interactions
    Transmission output rpm , speedometer signal
    Engine rpm, yours likely not a problem
    Selection position by actuator, could be a problem
    Hydraulic pressure in system , your seems ok
    Doors, front and rear bonnets, could be your problem if intermittent
    Sport switch, reverse switch, paddle switches,, auto switch, likely not sport switch, or reverse switch, or paddle switches, or auto switches, auto light should come on and go off when selected. You could try driving in auto and see if problem still occurs but I would think it will although in auto it will down shift way later than you doing so manually while slowing down.
    Gearbox input rpm, clutch position. Your could be the problem, do you see any oil or contamination if you pull off the rear clutch basket.

    Throttle position switch, likely not a problem based on what you said
    Key switch, yours likely not problem
     
  10. Mel Spillman

    Mel Spillman Formula Junior
    Silver Subscribed

    Nov 3, 2012
    635
    Sugar Land, Tx
    Taz: Thank you very much for your extensive and informative response. Linkage is good underneath and visibly shifts cleanly. I will check the speedo for variations. The trans light does not flash when gear indicator is flashing. Will have to drive car again to confirm if the 6th to 5th gears are the only ones affected, as I remember they were, but not positive. Again, thanks for taking time to respond. That was all very helpful, Sincerely, Mel
     
  11. taz355

    taz355 F1 Veteran
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    Feb 18, 2008
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    Grant
    No problem
    What I find is out of necessity I had to understand most of the system in order to describe the problem well enough For all of us on fchat can help you solve your problem.
    There is many of us on here that understand the system reasonably well but without you understanding it it will be hard for us to help you that’s all.
     
  12. taz355

    taz355 F1 Veteran
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    Find anything Mel?
     
  13. Mel Spillman

    Mel Spillman Formula Junior
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    Nov 3, 2012
    635
    Sugar Land, Tx
    I have not done anything with the car for the last month. Going to send it to a shop and let them look at it. I agree with you that someone needs to look at it that has experience with the system. Will keep you posted on any progress. Thanks for checking. Sincerely, Mel
     
  14. taz355

    taz355 F1 Veteran
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    Feb 18, 2008
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    Grant
    Good luck
    We will keep them honest
     

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