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Test Battery cooling fan

Discussion in 'Prius c Main Forum' started by Sayeed Anam, Apr 20, 2021.

  1. Sayeed Anam

    Sayeed Anam New Member

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    I am trying to test the cooling fan. does not seem like this fan is working. I bench tested to see if the fan moves. no luck. left the fan out and connected drove around but no fan movement.

    Anyone can advice on the 4 wires unlike Gen 2 had 2 pin connector (red, white, black, & blue) ?

    Thank you in advance for help.
     

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  2. bisco

    bisco cookie crumbler

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    try putting a tissue on the intake grille
     
  3. ChapmanF

    ChapmanF Senior Member

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    Probably works like the one in the Gen 3 liftback (this is from the liftback repair manual).

    S14.png

    You give it +12 V on IG0 and ground on GND0, you send it a signal for "I'd like you to run this fast please" on SI0, and it sends you back "ok, I'm running this fast" on VM0. (For some reason, they send the "please run this fast" signal from the power management control ECU, but the "ok, I'm running this fast" signal goes to the battery smart unit, who translates it into "ok, he's running this fast" messages and sends those over the comm bus back to the power management control ECU. Rube Goldberg is alive and well....)

    I am not finding details in the manual about the exact nature of that SI0 signal, whether it is a pulse train (like the way the water pump works) or a voltage range.
     
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  4. Sayeed Anam

    Sayeed Anam New Member

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    I found some more info. getting P0A84 code. Checked the 10A fuse that was blown. replaced no change. Is there a Relay or Controller ? location?

    Thanks
     
  5. Sayeed Anam

    Sayeed Anam New Member

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    Tried that, hooked up a new fan, replaced the 10A fuse that was blown, checked #29 a 30A for fan. Usually there is a controller/Resistor with most blower fan. I don't see anywhere. still the P0A84 code is there. No corrosion everything is clean. Battery and Fan under the seat. There has to be another fuse or Relay.

    Appreciate in advance any help
     
  6. Sayeed Anam

    Sayeed Anam New Member

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    another piece of information. The 10A #37 fuse blown again while test driving. Fan does not run from the scanner. there must be a short somewhere.
     
  7. bisco

    bisco cookie crumbler

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    i hope it isn't rodente :( have you owned the car since new?
     
  8. ChapmanF

    ChapmanF Senior Member

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    It is always best to look in the repair manual and wiring diagram for your model (more info), but to the best of my knowledge what you've got in the c is pretty close to what is used in the liftback, as shown in the circuit diagram a few posts above.

    Is the fuse you are replacing the "BATT FAN" fuse in a unit that looks like this, in the underhood fuse box?

    uD.png

    If so, the relay you're looking for (that's shown in the diagram above) is that unit. It's called an integration relay, which as you can see also has the relays and fuses for EFI MAIN and IG2.

    You might have better options for troubleshooting the problem than just guessing about the relay. You've probably got about 16 pages of troubleshooting advice in your repair manual in the section for the P0A84 code; at least that's about what I'm seeing in the liftback manual, and I'd bet yours is similar.
     
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  9. Sayeed Anam

    Sayeed Anam New Member

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    Trying to help a friend. most common problems are usually reported by other users here. Thought someone may have had similar issue.
     
  10. Sayeed Anam

    Sayeed Anam New Member

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    Appreciated your help.
     
  11. ChapmanF

    ChapmanF Senior Member

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    I just didn't look enough; it's Waveform 5 at the start of the Power Management Control ECU diagnostics section.

    Looks (by eyeballing that diagram) to be a roughly 400 Hz square wave, and probably the % of duty it is pulled down gives the speed you want (my guess, anyway, because grounding it apparently works on the bench as a quick way to see if the fan runs).
     
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  12. Abdul Nassir Salehi

    Abdul Nassir Salehi New Member

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    Hi dear Sayeed Anam
    Unfortunately it looks my car has same problem because the same code shows
    And I cleaned all connectors and cooling fan under the seat as well
    But still same
    It’s really a big headache any other update or have you sorted yet
    Any idea or advice please thank you
     
  13. rjparker

    rjparker Tu Humilde Sirviente

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    Assuming you are blowing fuses:

    I would disconnect the blower and replace the fuse. Drive a short test route. If the fuse does not blow, replace the blower assembly.