430 - P2794 Error Code | FerrariChat

430 P2794 Error Code

Discussion in '360/430' started by BlacktopRacing, Jul 21, 2019.

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  1. BlacktopRacing

    BlacktopRacing Formula Junior

    Sep 18, 2016
    912
    Pittsburgh
    Full Name:
    Dale
    This morning, went to drive to the Pittsburgh Vintage Grand Prix and the car wouldn't go higher than 2nd gear. Drove home, grabbed fluid and wrenches to top off the reservoir thinking that was the cause, but went the restart it and no light or issue. So, drove to the event. Went to drive home at the end if the day and same issue. Was planning to drive home in no higher than 2nd gear, but then it started working again. Have not tried to top off fluid yet because I want to see if anybody else experienced it, and if so, what the cause/solution was.

    Symptoms: F1 pump light on speedometer cluster, check engine light is warning cluster, error code P2794 on OBII reader (see image).

    Cause(s): ?
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  2. BlacktopRacing

    BlacktopRacing Formula Junior

    Sep 18, 2016
    912
    Pittsburgh
    Full Name:
    Dale
    My apologies for the typos above. Hopefully it is understandable.
     
  3. LorenzoR

    LorenzoR F1 Rookie
    Rossa Subscribed

    well i hate to say this but i have a feeling its a sensor. Im going with potentiometer which is on the actuator
     
  4. BlacktopRacing

    BlacktopRacing Formula Junior

    Sep 18, 2016
    912
    Pittsburgh
    Full Name:
    Dale
    Rhank you for your reply! Why do you hate to say that? Is it not a DIY-type service? There seems to be numerous potential cause according to link below, so wondering what would lead you think that particular potentiometer?
    http://www.engineobd2codes.com/p2794_ferrari-f430.html
     
  5. LorenzoR

    LorenzoR F1 Rookie
    Rossa Subscribed

    Sensors/potentiometers issue is not something the average guy can fix. From your description it sounds like to me that your car is having a hard time finding a gear so thats why im thinking this way. Potentiometers and certain sensors help the actuator go into gear among other things like the solonoids on the power unit. If those solonoids leak you can have same issues. That website you linked seems very very broad. I wouldnt go by that. These are just some opinions i have there are other things it could be. I hope im totally wrong and its an easier fix. Id get it on a sd3 to have leakage rates checked and they can help pinpoint it more
     
  6. BlacktopRacing

    BlacktopRacing Formula Junior

    Sep 18, 2016
    912
    Pittsburgh
    Full Name:
    Dale
    #6 BlacktopRacing, Jul 22, 2019
    Last edited: Jul 22, 2019
    I don't think its having "a hard time finding a gear", but rather choosing to limit itself to no more than 2nd gear, for whatever reason unbeknownst to me. Once it warms up and is driven, it starts to work normal, which is why I suspected low fluid, but then again, I think low fluid has it's own code. So I don't want to add fluid if it doesn't need any. I think I need to figure out why it wants to limit itself to 1st and 2nd gear when cold.
     
  7. MCASEY

    MCASEY Rookie

    Apr 1, 2015
    42
    Sydney Australia
    #7 MCASEY, Jul 22, 2019
    Last edited: Jul 22, 2019
    Check your chassis "Ground" or Earth connections with the wiring loom. This causes lots of strange and heat related problems.

    There are many points where the wiring looms "grounds" join to the chassis, the Workshop manual has a good drawing with the attachment points.
     
  8. BlacktopRacing

    BlacktopRacing Formula Junior

    Sep 18, 2016
    912
    Pittsburgh
    Full Name:
    Dale
    Thank you for your reply. I don't believe the symptoms are indicative of a grounding issue. This is not sporadic.
     
  9. 24000rpm

    24000rpm F1 Rookie

    I dont think p2794 exist in the f430 error reportior, but I am no expert.
    You might want to use another scanner to see that again
     
  10. BruceC

    BruceC Karting
    Silver Subscribed

    Apr 26, 2018
    249
    Tucson, AZ
    I have had the same issue very occasionally since April. I also installed the Scud eMT relay ~ 1 year ago primarily to proactively avoid a hydraulic pump relay failure and to monitor the system for possible performance issues > https://www.scuding.com/Shop/en/ecu-solutions/101-smart-emt-relay-ecu.html

    I am periodically getting faults reported on the relay monitor that are consistent with the upshift failure (actually the module had been occasionally reporting faults before I started experiencing upshift issues). Ran into another 430 owner at a recent event experiencing the same issue - seems like this is cropping up a lot lately. I copied the email exchange below that I had with Stef (owner Scud Ing Swiss) - he has or had a 430 at one time, so you may find it helpful. There's also another thread running on FC that I believe is related > https://www.ferrarichat.com/forum/threads/f430-e-diff-electronic-differential-info.577194/

    Unfortunately, I haven't come across any information that clearly points to a specific component that is likely to be the cause. Waiting on our Indie to return from the Challenge Race - if I learn anything new, I'll update this thread.

    [feedback from Scuding Swiss >
    Hello Bruce,

    Thanks for the videos. I confirm that you're having fault code 1, what means that your pump has been priming during 10 secs or more. It means that your hydraulic system has an issue in building up the hydraulic pressure to 50 bars and early warned you about this issue. A hydraulic system in good condition usually takes only 4 secs maximum, often less than that. Causes can be a failing pump, accumulator or hydraulic pressure leaks at the power unit, TOB or E-DIFF valve. If you often start having this fault code, I highly recommend that you get your hydraulic system checked before you get a more serious issue leaving you stranded on the road. This can be easily monitored with a diagnostic system like the SD3, SDX or DEIS.

    I hope this helps,

    Stef]
     
  11. BlacktopRacing

    BlacktopRacing Formula Junior

    Sep 18, 2016
    912
    Pittsburgh
    Full Name:
    Dale
    Can anybody link me (us) to the diagram that shows all the ground points? I guess it's worth checking some around where the sensors that were removed/replaced during the header install. Thanks.
     
  12. BlacktopRacing

    BlacktopRacing Formula Junior

    Sep 18, 2016
    912
    Pittsburgh
    Full Name:
    Dale
    A local high-end service center ran an intermediate diagnostic test on my car and found a P1741 code - Engagement potentiometer. This did not come up on my OBDII scan tool. Is this the likely culprit, or is this the first in a long line of things that could be wrong, but not necessarily?
     
  13. LorenzoR

    LorenzoR F1 Rookie
    Rossa Subscribed

    That's the potentiometer that I mentioned earlier in the thread. I believe it's the potentiometer in the actuator. If so the actuator has to come out. The actuator in these cars really isn't that hard to get out. Either way I think you're going to have to make a trip to the dealer or somebody who has the correct computers
     
  14. BlacktopRacing

    BlacktopRacing Formula Junior

    Sep 18, 2016
    912
    Pittsburgh
    Full Name:
    Dale
    Thanks. So you're saying it's not a DIY project because computer reprogramming is involved?
     
  15. LorenzoR

    LorenzoR F1 Rookie
    Rossa Subscribed

    Yes not a Diy. If thats what the issue is then in my opinion it would need computer reset. See what ur shop says as im curious
     
    BlacktopRacing likes this.
  16. BlacktopRacing

    BlacktopRacing Formula Junior

    Sep 18, 2016
    912
    Pittsburgh
    Full Name:
    Dale
    I received the Potentiometer kit today (248095) and am wondering if it's something easy to install, or if I need to take it to a service shop? It seems that all one needs to do is put the car on a lift, remove the undertray, and you should see the potentiometers on the transmission, with a shield over them? Anyway, I'm wondering if an ECU re-learn will need initiated?

    Thanks,
    Dale
     
  17. LorenzoR

    LorenzoR F1 Rookie
    Rossa Subscribed

    Potentiometers for the actuator on the inside of the actuator which means the actuator has to be removed but thats the easy part. I think it can be done without removing hydraulic lines. What im unsure of is the installation of the potentiometers and relearn. Its been awhile scince i did it
     
  18. LorenzoR

    LorenzoR F1 Rookie
    Rossa Subscribed

    look at some pictures of actuators on eBay and that will give you an idea of where they are located
     
  19. LorenzoR

    LorenzoR F1 Rookie
    Rossa Subscribed

    Attached Files:

  20. BlacktopRacing

    BlacktopRacing Formula Junior

    Sep 18, 2016
    912
    Pittsburgh
    Full Name:
    Dale
    Thanks for the pictures :) I am still unsure if there is hydraulic fluid involved in replacing the potentiometers, however, it looks like there is not.
     
  21. LorenzoR

    LorenzoR F1 Rookie
    Rossa Subscribed

    I dont remember how much play there would be in the lines, but if you can pull the actuator away from the gearbox far enough to replace them you may be ok. As i mentioned before you may need to have computers relearn on sd3. Whatever you do if you try this yourself make sure car is in neutral and battery switch is off. And also when you remove those potentiometers, lift them up slowly as i dont remember whats under them. Maybe someone here can chime in.
     
  22. BlacktopRacing

    BlacktopRacing Formula Junior

    Sep 18, 2016
    912
    Pittsburgh
    Full Name:
    Dale
    Fenz, Friday at 3:37 PM Wrote:
    I belive that you have to remove the F1 actuator to be able to replace the potentiometers, and then recalibrate the actuator with an SD3.
    Perfect opportunity to change the fluid.
    -----
    Is this true? So even if I do the work myself, or have a local shop do it, I'll need to pay a visit to the dealer anyway?
     
  23. LorenzoR

    LorenzoR F1 Rookie
    Rossa Subscribed

    I think I've been trying to say this all along. If you can pull the actuator far enough away, just far enough to replace the potentiometers then you won't have to deal with no hydraulics. But you may still have to bring it to a dealer the hook up to an sd3. The good part about doing it yourself to some degree is not paying the dealer a bunch of money to remove the actuator and install the potentiometers. The bad part is if you do it yourself and bring it to a dealer to reprogram they may have issue with it. Maybe before you start the job it would be a good idea to call the dealer and said hey I have a car that potentiometers were just replaced can you do a relearn on it for me and see what they say
     
  24. mwstewart

    mwstewart F1 Rookie

    Feb 5, 2014
    2,623
    England
    Full Name:
    Mark
    No need to disturb the hydraulics. You may install the new pots without a self-learn and the chances are that it will shift well enough to allow you to get to a shop to have it done.
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