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2001 prius temp. control problem

Discussion in 'Generation 1 Prius Discussion' started by yotatoter, Mar 22, 2011.

  1. yotatoter

    yotatoter Member

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    Hi all, I am new to prius chat but not to toyota, I just bought a 2001 prius with 184k and it needs a battery which with all the post I read on here,I will attempt to swap the 2 bad modules. I will post in a few days and let you know how it went. Reason for this post is this, my heater control knob does not work,it is either completely hot, or no heat at all. I looked under the driver side panel and noticed the electric motor will either open or close the heater valve completely ,as soon as the temp control goes past about 65. Does this sound like a bad temp. control ,or how do I test it?? thanks for any advise..
     
    #1 yotatoter, Mar 22, 2011
  2. ChapmanF

    ChapmanF Senior Member

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    The first step would be to find out if the control board already has any diagnostic codes for you.

    Start with the ignition OFF and the fan switch OFF. Turn the ignition to ON (only ON) and then, all within 5 seconds, press the A/C button 3 times then turn the fan switch to AUTO.

    You should see the LEDs in all four heat/ac control buttons blink together slowly four times, and then just the LED in the a/c button blinks.

    It can blink in two-digit code groups where, for example, "blink (pause) blink blink (longer pause) blink blink blink (pause) blink" would be codes 12 and 31. Write down all the codes you get. You know you're done when it starts repeating itself. Then post the codes here.

    If you just get a steady fast blink then there aren't any codes; the control isn't aware it has any problems, so in that case the problem just has to be found the old fashioned way.

    -Chap
     
    #2 ChapmanF, Mar 23, 2011
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  3. yotatoter

    yotatoter Member

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    Thank you,I will do that and reply shortly with any codes..
     
    #3 yotatoter, Mar 23, 2011
  4. yotatoter

    yotatoter Member

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    Okay so I pulled the codes and got what looks like 11, and 21.. Does that sound like the correct codes??
     
    #4 yotatoter, Mar 23, 2011
  5. yotatoter

    yotatoter Member

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    Okay ,an update on the heater temp. control,I remove the lower dash part where the cabin temp. sensor is located an found a wire harness that was unplugged. Looks like somebody else was in the dash and forgot to plug it back in.. I tried it again and it still did the same thing," heater valve wide open", how ever the car was not running so I am thinking that with the cabin temp at about 60 as soon as you turn on the heat to about 70 it will still go wide open till the cabin temp gets closer to 70. Am I thinking correctly?? FYI I still get a code 21, but the car was in the garage and not in the sun,so I am thinking that could still thro code 21?? Any more info?? Thank you for the great help so far>>>
     
    #5 yotatoter, Mar 23, 2011
  6. ChapmanF

    ChapmanF Senior Member

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    It definitely sounds like you're thinking correctly so far. You didn't mention having access to the meanings of the codes, but somehow you did look at the temp sensor in the dash to make your code 11 go away (which was correct) and you know your 21 is because you're out of the sun (which is correct). Could it be that you've really had the manual in front of you all along and you're hustling us by pretending not to? :)

    Now I'm just waiting to hear how it works when the car's actually running!

    -Chap
     
    #6 ChapmanF, Mar 25, 2011
  7. ChapmanF

    ChapmanF Senior Member

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    If there is any remaining problem ... you might have noticed that the temperature sensor in the dash also has a little hose behind it, leading to the low-pressure side of the blower. That causes a bit of cabin air to be sucked in over the sensor so it isn't just reading the temperature of the dash. If you still think it's not getting good readings, you might check that the hose wasn't also disconnected, and isn't plugged, or something.

    -Chap
     
    #7 ChapmanF, Mar 25, 2011
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  8. yotatoter

    yotatoter Member

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    Hey chapman, Thanks for the post. No I do not have a manual for it. "I wish I did" I found the info on here!! I will definately let you know when I get it done,I have been busy at work. I hope to have it going by Sat..
     
    #8 yotatoter, Mar 30, 2011
  9. yotatoter

    yotatoter Member

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    Okay a quick update,the heater now works but I am getting a code p3191. I will update more in a little while. PS. I have the battery back in and took it for a drive but got the above code..
     
    #9 yotatoter, Apr 1, 2011
  10. yotatoter

    yotatoter Member

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    After a little more driving the check engine light went off and the triangle ofdeath did too. I am now getting 47.5 mpg. and I drove a total of 55 miles . I totally love this car!!!!!! Thanks for this great forum!!
     
    #10 yotatoter, Apr 1, 2011
  11. Patrick Wong

    Patrick Wong DIY Enthusiast

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    DTC P3191 is the engine no-start code. This is logged when the gasoline engine takes longer to start than the ECU thinks is reasonable.

    I suggest that you clean the throttle body interior and throttle plate using the minimum necessary amount of throttle body cleaner.

    Remove the air cleaner housing so that you can access the throttle body. Spray the cleaner fluid on a clean cloth or paper towel, then use that to scrub the black gunk off the TB interior. Rotate the spring-loaded throttle shaft 90 degrees to expose the bottom of the throttle plate for cleaning.

    If the iridium spark plugs have not been replaced within the last 60K miles then it would be good to do that as well, using the correct NGK or Denso plugs as listed in the owners manual.
     
    #11 Patrick Wong, Apr 1, 2011
  12. yotatoter

    yotatoter Member

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    Thank you Patrick,The check engine light went off on its own after about 20 min. of driving and has not come on since. But yes that is the next thing on my list to clean the throttle body. I have done all the other "stuff" trans oil change ect. I now drove it 400 mi. and have an average of 46.1 so I am thrilled with the car!! Thank you all for your help..
     
    #12 yotatoter, Apr 4, 2011
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