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slow down warning light

Discussion in 'Technical Q&A' started by ROCKY1634, Mar 17, 2004.

  1. ROCKY1634

    ROCKY1634 Karting

    Nov 12, 2003
    80
    help....
    my slow down light comes on right at start up on my 1997 355, i thought this light only came on when the cats overheated, being that the cats are still cold why would the light come on? has anyone had this same problem? sometimes the light is blinking other times it is steady on.
    thanks
     
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  3. Steve Magnusson

    Steve Magnusson F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    19,750
    Texas
    Full Name:
    Steve Magnusson
    bad ECU/Gremlin


    Notoriously flaky on TRs (I've got two fresh warning light ECUs) -- don't know if 355 are somewhat "improved" though...
     
  4. jenzo

    jenzo Karting

    Nov 9, 2003
    246
    LONDON
    Full Name:
    JENZO
  5. colo348

    colo348 Karting

    Nov 1, 2003
    141
    Colorado
    Full Name:
    Jim
    Rocky,
    I just went through the same thing on my TR. The 7-12 ECU had to be replaced. So, I agree with Steve. The ECU in my TR was just replaced 16 months ago. Good luck.
    Jim
     
  6. normhuff

    normhuff Formula Junior

    Dec 14, 2003
    711
    Peoria, IL
    Full Name:
    J. Norman Huff, Esq.
    Also had the same thing repaired last week on the TR. The 'slow down cyl 7-12' light would come on after starting the car and would stay on for about ten minutes before going out. Bad ECU as mentioned. Not cheap either. $371 for the part, 1.5 hours dealer labor to fiddle with it cost $550 total...
     
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  8. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    7,317
    When the car is first started, the ECU expects the rear oxygen sensor to read rich until the cats light off, and then consistently read lean from then on while the front sensor oscilates between rich and lean on a (more or less) regular basis. Apparently this is not happening. Potential causes: A) oxygen sensor heating element burned out, B) oxygen sensor out of range (dead or dieing or corroded), C) Cat dead or dieing, D) wiring gremlins.
     
  9. Steve Magnusson

    Steve Magnusson F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    19,750
    Texas
    Full Name:
    Steve Magnusson
    Mitch -- Are you sure the O2 sensor(s) are involved in the over-temp warning light function immediately after cold start-up? My understanding was/is that the O2 sensors don't make a meaningful/useable output until they reach a fairly high minimum temperature (and that they would trigger a "check engine" light rather than a "slow down" light).

    ROCKY -- forgot to ask in the first message -- how's your self-test at key "on" been behaving?
     
  10. ROCKY1634

    ROCKY1634 Karting

    Nov 12, 2003
    80
     
  11. ROCKY1634

    ROCKY1634 Karting

    Nov 12, 2003
    80
    Steve..
    self test at key "on" seems to be ok, all lights come on than go off, except for the slow down light. I am also getting a P1449 code when I use the code reader, don't know what this is as I don't have a list of Ferrari codes.
     
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  13. ghost

    ghost F1 Veteran
    Lifetime Rossa

    Dec 10, 2003
    9,844
    Singapore
    I'm following this thread with some interest as, I too, occassionally get the "Slow Down 1-4" light to come on, but then disappear. For me, though, the light comes on not immediately after starting, but usually a couple of minutes later, and then usually disappears a few minutes after I get the car moving. I first thought it was an overheating issue, but then the weather here in the Northeast has been crisp and cool, so it probably isn't. Do you guys think it might also be a faulty ECU? The car has just had it's 30K servicing.

    Assuming it is, I guess the second question is: can you live with this false positive for a while, or should it be changed immediately?

    I'd appreciate your thoughts.
     
  14. Juice It

    Juice It F1 Rookie

    Sep 22, 2002
    3,233
    Maryland (DC Suburb)
    Full Name:
    Jeff
    Do you get the half power out of the engine or just the light. Mine did this a few times as well on my 355 and seems to have went away on its own.
     
  15. ghost

    ghost F1 Veteran
    Lifetime Rossa

    Dec 10, 2003
    9,844
    Singapore
    Just the light Jeff. Based on your experience, I assume, then, that this could be just another lovely 355 "quirk" that some of us have to live with. I think you're right, as the car just went through it's 30K where it was gone over with a fine tooth comb.
     
  16. Steve Magnusson

    Steve Magnusson F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    19,750
    Texas
    Full Name:
    Steve Magnusson
    ROCKY -- You put too much positive political spin on your answer -- your over-temp warning light self-test is NOT WORKING ;). You can always try refreshing the thermocouple connections (and any other connections at the ECU where the thermocouple connects) and checking the thermocouple itself for continuity (and maybe room temp voltage output), but those would be the lucky fixes.

    I, too, am surprised you guys aren't having more "power loss/bank shutdown" issues since I thought these later systems (348 and later) were designed to shut things down on a positive (even if false) over-temp signal -- because (as you guys almost always demonstrate) the driver rarely "stops" when the warning light comes on. Perhaps they've got more smarts in the overall system to ignore a positive over-temp signal if it previously figured out that the initial self-test was wacko itself, but just speculation (always a little frightening when they add complexity to deal with a problem caused by added complexity ;)).
     
  17. Dave

    Dave F1 Rookie

    Apr 15, 2001
    2,722
    Little Rock
    Full Name:
    David Jones
    "I am also getting a P1449 code when I use the code reader, don't know what this is as I don't have a list of Ferrari codes"

    I know this won't fix your current problem, but...
    I think it would be invaluable to have an online database of the error codes and description for the new computer cars.
    I just went through this with my Range Rover.
    Try and get a dealer to translate the code # for you is like pulling teeth.
    But I was able to find an online database of ECU codes and translations on line to diagnose the problem.
     
  18. chaa

    chaa F1 Veteran

    Mar 21, 2003
    5,058
    Mine started to do the same thing yesterday morning(light 5-8) i never lost power, after i booked it in for next week, bloody thing went out last night, sod it still going to take it in and use up some of me waranty.
     

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