512TR thermocouple control unit | FerrariChat

512TR thermocouple control unit

Discussion in 'Boxers/TR/M' started by bazzis, Apr 13, 2017.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. bazzis

    bazzis Karting

    Nov 5, 2003
    217
    Sarratt, Herts
    does anyone have a thermocouple control unit part no : 148449 / 154470 , cant find one anywhere in the uk, as my car doesn't have cats , is there anyway to run car without them....
     
  2. Arvid

    Arvid Formula Junior
    Silver Subscribed

    May 28, 2012
    668
    Norway
    Full Name:
    Arvid Andersson
    There are currently three new and three used examples for sale on ebay :)

    Items 120569167304 - 121911617177 - 121912567992
     
  3. qwazipsycho

    qwazipsycho Formula 3

    Oct 30, 2004
    1,176
    Utah
    Full Name:
    Scott
    I think they're the same in the TR. Just a glorified light switch. Unplug it. Someone here will correct me quickly if I'm wrong but in the TR they fail frequently and $600 is too much for a light switch.

    DISCLAIMER: These are designed to tell you when your cats are going to light your car on fire. If you don't care about knowing when that happens, then happy motoring.

    They typically lose the seal on the backside and moisture gets inside and causes them to lie to you about your cats lighting up.

    Cats belong in the wild. Not in your house, not in your car.
     
    Danyboy likes this.
  4. bazzis

    bazzis Karting

    Nov 5, 2003
    217
    Sarratt, Herts
    unfortunately my 512tr will not run without these boxes working properly.....
     
  5. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    33,736
    Austin TX
    Full Name:
    Brian Crall
    Every other one I have seen works just fine when they are disconnected. I guess your car is special.
     
  6. bazzis

    bazzis Karting

    Nov 5, 2003
    217
    Sarratt, Herts
    do you just unplug the wire from the thermocouple control unit to the ECU...if so will try again, thanks
     
  7. bazzis

    bazzis Karting

    Nov 5, 2003
    217
    Sarratt, Herts
    just tried car with thermo modules disconnected..car runs but have 1/6 and 7/12 warning lights on. Is it ok to use with these lights on, car doesnt have cats , its a Euro spec car.....
     
  8. lear60man

    lear60man Formula 3

    May 29, 2004
    1,829
    Los Angeles
    Full Name:
    Christian
    It should run fine as the thermocouplers are just a thermometer that says 'Hey pal, your cats might be running hot, but more likely ive failed again'.

    I removed mine the first month I had my TR. Like others have said, they are expensive to replace and have a lifespan of a gnat.

    Since your car does not have cats, I would unplug the power going to the 1/6 7/12 lights. No cats, no Thermocouplers, no dash lights......no problem.
     
  9. Melvok

    Melvok F1 World Champ
    Owner Silver Subscribed

    Jul 25, 2008
    14,101
    Amersfoort, The Netherlands, Europe.
    Full Name:
    Mel
    Many take the little bulbs out of the dash ...
     
  10. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,039
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #10 Steve Magnusson, Apr 14, 2017
    Last edited: Apr 14, 2017
    bazzis -- Are you just unplugging the thermocouples from the warning light ECUs, or are you unplugging the warning light ECUs from the wiring harness? Your comment that "with (things) disconnected...car runs but have 1/6 and 7/12 warning lights on" implies that you are just unplugging the thermocouples from the warning light ECUs; whereas, Brian's "disconnected", I believe, is unplugging the warning light ECUs from the wiring harness (disclaimer -- I don't have access at the moment to the 512TR wiring diagram to check this point).

    This system on a 512TR is a bit different than on TR. On a TR, it's just a temperature sensor that drives a warning light with no relationship to the injection system (so if you get a false indication, just taking out the bulb, or unplugging it completely, turns off the bulb without affecting how the engine runs at all, nor does having the light come "on" affect how the engine runs at all). However, since no one ever actually slowed down, or stopped, when the warning light came "on", on the 512TR, they added an intelligent connection to the Motronic system. Consequently, if the ECU fails and wrongly "thinks" things are too hot (or has a disconnected thermocouple), it still sends the "slow down" signal to the Motronic system so just removing the bulb in the dash doesn't change/fix the engine running behavior (nor does just unplugging the thermocouples). Anyway, just wanted to point out this difference between the two models.

    Note -- Do not take this a recommendation to disable this system on either a TR or 512TR if you have active cats in place anywhere in the exhaust path.
     
  11. tf308

    tf308 Formula 3

    Dec 14, 2003
    1,168
    Virginia Beach
    Full Name:
    Tim
    I can't remember exactly, but I remember reading somewhere on F chat how these work.

    I think that when everything is ok, the box outputs 1.5V. I think this signal lets the car run.

    I have seen so many electronic repair company's fix simple boards like this. I'm surprised no one is doing it with these units
     
  12. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,039
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    The difficulty with doing a repair is that they "pot" the components on the PCBA in an epoxy by filling the entire inside of the outer case (trying to improve the ruggedness so it can survive better in the demanding underbonnet environment). Way hard (and super tedious/time consuming) to get the epoxy off without damaging the components.
     
  13. Red Sled

    Red Sled Formula Junior

    I always thought that cat over-temp signal triggered the slow down lights AND cut the fuel pump(s) to the relevant bank. Yours runs however. Am I missing something?
     
  14. bazzis

    bazzis Karting

    Nov 5, 2003
    217
    Sarratt, Herts
    I unplugged the cable going to the ecu, didn't bother with the thermocouple connector, car seemed to run fine , but a bit disconcerting seeing two bright red lights on all the time ! but will place two little stickers in appropriate position on dash ! will run it like this for a while and see what happens, thanks for all inputs ....
     
  15. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
    8,866
    southwest germany and thailand
    Full Name:
    romano schwabel
    those 2 red lights would irritate me during driving. even if you put some tape on you still see this red.
    better to take the bulbs out
    because if there really goes on an other red light you not mention it - or when then it may be to late? :(
     
  16. bazzis

    bazzis Karting

    Nov 5, 2003
    217
    Sarratt, Herts
    does anybody know how to check the correct line voltages for the thermocouple leads....may be possible to fabricate a useable box...
     
  17. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,039
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    Try individual searches on the three F PNs: 141037, 142581, and 154470. I'm pretty sure it's come up before -- might not be it any of those threads, but those threads might have links to other threads that have more information.
     
  18. tf308

    tf308 Formula 3

    Dec 14, 2003
    1,168
    Virginia Beach
    Full Name:
    Tim
    Just google search "Ferrari cat ecu"

    I'm pretty sure it doesn't matter which "newer " Ferrari with a moronic that you have. My guess is the wire connector may be slightly different, but that's it.

    There is a Canadian company that re engineered these and also supplies an aerospace gauge to read temps on the fly
     
  19. tf308

    tf308 Formula 3

    Dec 14, 2003
    1,168
    Virginia Beach
    Full Name:
    Tim
    *motronic not moronic
     
  20. JIMBO

    JIMBO Formula 3
    Silver Subscribed

    Oct 31, 2003
    1,321
    Bradenton, Florida
    Full Name:
    Jim DeRespino
    I installed test pipes (no cats) on my 1994 512TR at 11,000 miles and unplugged the thermocouple ECU's from the wiring harness. I've had no lights, no problems since (just past 63,000 smiles).
     
  21. bazzis

    bazzis Karting

    Nov 5, 2003
    217
    Sarratt, Herts
    maybe Euro cars have different ECU's , if i disconnect thermocouple units i have two bright red lights on all the time ! and have been advised not to run car like that....
     
  22. JIMBO

    JIMBO Formula 3
    Silver Subscribed

    Oct 31, 2003
    1,321
    Bradenton, Florida
    Full Name:
    Jim DeRespino
    Don't just disconnect the sensors from the ECU, disconnect the ecu's from the main harness. Maybe Euro cars are different.
     

Share This Page