1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Car slows when climbing hill

Discussion in 'Gen 2 Prius Main Forum' started by kolez2000, Sep 11, 2021.

  1. kolez2000

    kolez2000 Junior Member

    Joined:
    Aug 20, 2021
    64
    9
    0
    Location:
    West Africa
    Vehicle:
    2005 Prius
    Model:
    N/A
    My Prius 2005 slows down when I try to climb a hill....it times it does drag when it was supposed to move with speed when I gas pedal the car, it gradually moves.
    Though there is working light from my battery.
    Could this be the reason why the car would not want to move fast when climbing a hill?
     
  2. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

    Joined:
    Oct 28, 2010
    7,668
    6,485
    0
    Location:
    Redneck Riviera (Gulf South)
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    Define.... "hill."

    In America, most people do not know the difference. Our government once stated that the difference between a hill and a mountain was 1,000 feet of local relief, but this was rapidly abandoned since, the eastern part of our nation is a lot like West Africa where "hill" and "mountain" are somewhat interchangeable.
    If you travel to Tanzania or Kenya or in some parts of the Atlas mountains - "hills" get a lot bigger.

    NORMALLY, 2005 Priuses are somewhat slower going UP hills than they are traveling down them because the car is rather underpowered and does not have a manual transmission.
    If the car is able to move at all and there are no warning lights then there is nothing seriously wrong with the traction (big) battery other than perhaps that it is old.
     
  3. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    10,096
    4,795
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    Probably has the original hybrid battery.
     
  4. mr_guy_mann

    mr_guy_mann Senior Member

    Joined:
    Sep 3, 2020
    3,206
    1,339
    0
    Location:
    NJ-USA
    Vehicle:
    2006 Prius
    Model:
    Four
    What do you mean "there is a working light from my battery"? Are you talking about the "gauge" in the center display (Multi Function Display) for the High Voltage battery? If so, please describe what it shows when you drive, particularly when going up a hill.

    Posted via the PriusChat mobile app.
     
  5. PriusCamper

    PriusCamper Senior Member

    Joined:
    Mar 3, 2012
    10,775
    4,372
    0
    Location:
    Pacific Northwest, USA
    Vehicle:
    2007 Prius
    Model:
    Two
    Do you have warning lights on dashboard?
     
  6. TMR-JWAP

    TMR-JWAP Senior Member

    Joined:
    Aug 12, 2016
    6,058
    5,783
    0
    Location:
    Columbia, SC
    Vehicle:
    2007 Prius
    Model:
    Touring
    I'm thinking this:

    Though there is working light from my battery.

    was meant to be this:

    "Though there is a warning light from my battery."
     
    PriusCamper likes this.
  7. PriusCamper

    PriusCamper Senior Member

    Joined:
    Mar 3, 2012
    10,775
    4,372
    0
    Location:
    Pacific Northwest, USA
    Vehicle:
    2007 Prius
    Model:
    Two
    English is a really, really hard language to learn... What's worse is that the US is one of the only places in the world you can get by knowing only one language. And add to that the fact that when you compare monolingual people to bilingual you basically explain all that's wrong with our country right now:

    "A steady stream of studies over the past decade has shown that bilinguals outperform monolinguals in a range of cognitive and social tasks from verbal and nonverbal tests to how well they can read other people. Greater empathy is thought to be because bilinguals are better at blocking out their own feelings and beliefs in order to concentrate on the other person’s. “Bilinguals perform these tasks much better than monolinguals – they are faster and more accurate,” says Athanasopoulos. And that suggests their executive systems are different from monolinguals’." The amazing benefits of being bilingual - BBC Future
     
  8. james nancy

    james nancy Member

    Joined:
    Aug 10, 2021
    110
    24
    0
    Location:
    suva,fiji
    Vehicle:
    2010 Prius
    Model:
    III
    But brother, the host asked that his car was weak uphill.
     
    edthefox5 likes this.
  9. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
    11,490
    14,095
    0
    Location:
    Tampa, FL
    Vehicle:
    2017 Prius
    Model:
    Two
    Hi @kolez2000. Some more information would help us help you. I can't tell if you actually have a problem or not.

    Is this a new situation for a car you've had for a while or is the car new to you? If this is a change in behavior, then it's a matter of determining if the traction battery is getting weak or maybe the car just needs a tuneup. If it's the original battery and/or if it's been rebuilt, a weak battery would not be a surprise. But it also would not be a surprise if a 2005 car needed a tuneup.

    Do you have any warning lights? If so, you need to read the codes with a code reader fluent in Prius. That will save a ton of time.

    If you just got the car and don't have a comparison, and there are no warning lights, the Gen 2 Prius can start to slow or at least work very hard on long steep hills. But it should not slow down if you press the accelerator hard enough.

    And just to satisfy my own curiosity, in what part of West Africa do you live?
     
  10. TMR-JWAP

    TMR-JWAP Senior Member

    Joined:
    Aug 12, 2016
    6,058
    5,783
    0
    Location:
    Columbia, SC
    Vehicle:
    2007 Prius
    Model:
    Touring
    And yes, all the OPs symptoms point to the car having a failing HV battery and being in limp mode. I've driven enough Gen 2 Prii with failing batteries to recognize that in about half a second.

    My Prius 2005 slows down when I try to climb a hill....it times it does drag when it was supposed to move with speed when I gas pedal the car, it gradually moves.

    Yes, in limp mode, the car engine will rev high very easily, but the car will accelerate very slowly. Even once it gets up to speed, even the slightest hill will severely cause speed to reduce.

    Many times, if you're able to leave a scanner attached to the OBD port, you can reset these codes on the fly and the car will drive normally until the code triggers again. It may take 10 seconds or 10 days to trigger again.
     
    jerrymildred likes this.
  11. pasadena_commut

    pasadena_commut Senior Member

    Joined:
    May 2, 2019
    1,331
    404
    0
    Location:
    Southern California
    Vehicle:
    2007 Prius
    Model:
    N/A
    What does the battery indicator on the dash show? Is it normally in the green or blue ranges when driving around on the flat? Does it very rapidly drop to one or two purple bars when you go up a hill and stay there? If that is the case you probably have a marginal HV battery, which can only supply a limited amount of boost before its voltage collapses. If the red triangle warning light is on things are even worse than that.

    Also, what is "going up a hill"? If it is a sustained 3000 ft climb I imagine that long before the top any Prius will have fully depleted the HV battery and will be limping up the hill at a reduced rate of speed, using just the gas motor, which is only 76 hp. If this happens at least be sure the AC is off because there is not a lot of oomph to spare in that situation.