F355 HVAC ECU

Discussion in '348/355' started by baschul, Jun 28, 2016.

  1. baschul

    baschul Karting
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    May 27, 2015
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    Brian S
    Hi all,

    The HVAC has not worked properly in my F355 for a couple years. The center console controls work correctly as the blower speed function works and the A/C compressor clutch engages when the temperature dial is set to cold and disengages when set to hot. The heater control valve is stuck on cold (moves freely if you remove the motor), the recirculation flap is stuck shut (button does nothing), and the dash air direction drum is set to the default position of air out of all three areas (foot well, defrost, and center vents) regardless of what position the air direction knob is set to.

    I individually tested the stepper motors for the recirculation flap, heater control valve, and the air direction drum. All worked properly. The recirculation motor already had the Hill brass replacement boss installed. I also tested the interior and exterior temp sensors, which both worked properly. Having done all of the testing, I have narrowed the problem down to the HVAC ECU which is apparently a common problem on these cars per all of the other FChat threads on this topic.

    I do however have a question for the others that have already done the HVAC ECU re-build and/or replacement. I am about to remove the HVAC ECU to send it out to ASI for re-building, but I wanted to know if I can safely operate the car normally while the ECU is out of the car. If I shut off the battery switch, remove the ECU, turn the battery switch back on, and drive the car normally with the HVAC controls set to off, will there be any problems or CELs? Would it be better to wait until the winter where I can leave the battery off for the whole time the ECU is disconnected from the car? I'm driving the car with the top down most of the time, but I can use the A/C on high with the top up and get the passenger compartment somewhat cool for the rest of the summer and fall if need be.

    I have a 1995 2.7 car for anyone that may be able to chime in with their specific experiences on this topic. Thanks in advance for the shared experiences.

    Brian
     
  2. LorenzoR

    LorenzoR Formula Junior
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    Sep 26, 2015
    870
    Sarasota Fl
    I just went thru the same thing. Theres a small chip inside your ac ecu that's bad. I drove mine for alittle while I was trouble shooting without issues. So I think your safe. The AC ECU is strictly for the AC. I fixed mine and its now working perfectly.
     
  3. F355Bob

    F355Bob Formula 3
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    Who fixed you ECU?
     
  4. LorenzoR

    LorenzoR Formula Junior
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    Sep 26, 2015
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    I troubleshooted it with the help of a forum member. Once we figured out which chip it was I replaced it myself. $5 bucs haha
     
  5. taz355

    taz355 F1 Rookie
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    Feb 18, 2008
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    From above post looks like asi whoever that is
     
  6. johnk...

    johnk... F1 Veteran
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    Jun 11, 2004
    5,683
    What was the part number for the chip? Source? Chip manufacture?
     
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  8. baschul

    baschul Karting
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    Please also provide pictures if you have them and some general details on what was done. I would prefer to repair my ECU myself if it's as simple as replacing a chip. I can solder well enough to get through it.
     
  9. brendon0

    brendon0 Formula Junior
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    Dec 13, 2003
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    Yes please post some details i would like to know this too
     
  10. Qavion

    Qavion Formula 3

    Feb 20, 2015
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    Did you cut the legs off the chip, then desolder the individual legs? Seems like this would be the easiest way (without buying specialist equipment). The chip may be $5, but you'd probably need solder, flux, variable heat solder gun, solder sucker (or braid), snips (wire cutters), etc... and good technique, of course. Too much heat will damage the chip and the board.

    Was the ECU easy to get into?
     
  11. JoshH

    JoshH Rookie

    May 16, 2016
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    Austin
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    Josh
    The HVAC system operates independently of the primary systems in the car, it will neither know nor care if the HVAC ECU is missing.
     
  12. LorenzoR

    LorenzoR Formula Junior
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    Sep 26, 2015
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    #11 LorenzoR, Jun 30, 2016
    Last edited by a moderator: Sep 7, 2017
    Chip number is TCA2465. You can find them on ebay for about 5 bucs plus shipping. Sorry but im traveling and I don't have my notes with me. But if you look at the pics of the circuit board, you will see 6 chips side by side. Im almost certain that I replaced the top right chip. That's the one that controls the stepper motor. You cannot just cut the legs off. There are products on the market that will remove the whole chip For about 10 bucs and will not damage the circuit board. You can find that on ebay to. Just google or you tube How to remove chips from circuit boards,,,Also make sure you get the correct solder when installing. You want solder that flows out. I forget what its called but im sure someone in here will know or ask an electronics shop. Borrow a solder iron if u don't have one. Buy the desolder kit for $10 or so. Usually the braid is with it. ALL this can be done for cheap. $30 TO $40 tops.
    Image Unavailable, Please Login
     
  13. Qavion

    Qavion Formula 3

    Feb 20, 2015
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    Thanks for the details! Cheers.

    Aka... "Flux core"

    Download TCA2465 Datasheet PDF (Dual Power Operational Amplifier)

    I see a few on eBay, some $5, some $50 (???). There seems to be quite a price range.

    TCA2465 Manu Siemens Package ZIP 9 Dual Power Operational Amplifier | eBay

    Can you remember if the chip was mounted in holes or on the surface of the board, like this ...

    https://www.youtube.com/watch?v=QiIy3Oe2UGI

    When fitting the chip, note the orientation (by dot or cutout)
     
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  15. LorenzoR

    LorenzoR Formula Junior
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    Theres no holes where these go. Their mounted on the surface. Go by the dot
     
  16. LorenzoR

    LorenzoR Formula Junior
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    1 item sold by elektronikposten







    IC TCA2465 G Siemens SMD




    IC TCA2465 G Siemens SMD

    Ebay number was this, not sure if this helps. ( 361212818203 )
    The sellers name is above.
     
  17. LorenzoR

    LorenzoR Formula Junior
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    1 item sold by sra-stores







    Fast Chip Kit for Quik SMD Removal




    Fast Chip Kit for Quik SMD Removal

    ( 111780734039 )
    Buy this to remove the chip...Its works great...You will need braid to suck up the excess solder after removing and also maybe when after installing the new chip
     
  18. brendon0

    brendon0 Formula Junior
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    Does anyone have details in what each of the 6 chips drive?
     
  19. LorenzoR

    LorenzoR Formula Junior
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    I figured out what most of them do but i have that info at home
     
  20. johnk...

    johnk... F1 Veteran
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    Jun 11, 2004
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    #18 johnk..., Jul 1, 2016
    Last edited: Jul 1, 2016
    It would be good info to have. You should write it up and post a PDF with all the info in it.

    Or, at least let ME know which amp controls the hot water valve. :)
     
  21. baschul

    baschul Karting
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    Yes, please post here for all to see once you get home and can put your hands on the information. Thanks.
     
  22. brendon0

    brendon0 Formula Junior
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    Yes would very much appreciate the info. I am having recirc flap and water
    mixing valve issues too.
     
  23. gothspeed

    gothspeed F1 World Champ
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    I haven't had problems with my console ECU (yet) .... but this info would be god to have if or when it does go on vacation ... :)
     
  24. F355Bob

    F355Bob Formula 3
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    He's selling his car so might not get the information we need.
     
  25. gothspeed

    gothspeed F1 World Champ
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    ......... :eek:
     
  26. LorenzoR

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    Sep 26, 2015
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    no don't worry about that guys. ill post up what I have once I get back to florida...I became a snowbird at age 57 haha so im back and forth up north then florida
     
  27. baschul

    baschul Karting
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    Thanks. I'd definitely like to have the info.
     

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