!999 550M limp home mode cause (?) and solutions | FerrariChat
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!999 550M limp home mode cause (?) and solutions

Discussion in '456/550/575' started by louismidiri, Jul 17, 2013.

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  1. louismidiri

    louismidiri Rookie

    Jul 16, 2013
    10
    #1 louismidiri, Jul 17, 2013
    Hi all,

    Yesterday my 550M began running rough and was hesitant to rev. Also there was a definite loss of power. The 'check engine ' icon illuminated and the message center flashed "Check Engine" and "Slow Down" alternately.

    A long-term test of a 2001 550M by Edmunds encountered a similar problem. Though theirs was intermittent, mine is constant.

    While returning home in Limp Home mode my Oil pressure and Oil temperature were normal. My Water temperature was a bit cooler than normal. Once home and shutting down the engine I checked the oil. Dipstick registered normal oil level, color and consistency. After the engine cooled I checked the expansion tank. The anti-freeze was a bit low but the tank was definitely not dry.

    In Edmunds report initial replacing of a sensor of some kind failed to solve the problem. The 2nd attempt to diagnose the problem found a loose "EMU" connection ... which apparently can happen under normal driving conditions. The problem did not reoccur from that point forward.

    Can anyone tell me where the "EMU" is located? It's not listed in the owners manual breakdown of the fuse panel.

    Louie
     
  2. mcypert

    mcypert Formula Junior

    Jun 7, 2012
    369
    Houston, Texas
    Full Name:
    Mark Cypert
    #2 mcypert, Jul 19, 2013
    Last edited: Jul 19, 2013
    Hi Louie and welcome to F-chat.....

    I don't know much about your car. I have a 456 w/ the 2.7 Motronic ECU while yours has the 5.2.

    You might want to look at the 550 workshop manual (WSM). Get one for free at:

    All Ferraris

    The CEL/ SD lights can be triggered by any number of things. Just guessing here, but you mentioned a slightly lower coolant temp. Sounds like you might be running on only one bank of cylinders? Again, there's a number of things that can cause this including lack of power to the ECU, I believe there is one for each bank on your car. Easy way to tell is if one side of the exhaust is cold.

    Don't panic....It's probably something simple...

    Well, at least you have a start....Come on guys.....Let's help Louie with some advice.....

    Regards......Mark
     

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