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

2001 gen1 too high rpm on gas engine. It acts like a car stuck in first gear.

Discussion in 'Generation 1 Prius Discussion' started by Johog, Jun 18, 2017.

  1. Johog

    Johog Junior Member

    Joined:
    Apr 18, 2017
    9
    1
    0
    Location:
    Minnesota
    Vehicle:
    2001 Prius
    Model:
    Two
    I have a 2001 gen Prius. I just bought from a friend ready to junk it. It has 195,000 miles on it. It was throwing codes for bad HV battery. She had a mechanic look at it but sounds like they did not do much hybrid work. It has a good body and interior.

    The bad news is she then parked it in January and left in till a few weeks ago.
    This is during a Minnesota winter. Now I bought from her as a project. I also bought a "junk" gen 1 HV battery from salvage yard. It was also throwing battery codes so I got it cheap. I do not know how to figure out how to do some pretty intensive load testing. I used the 38 best modules to balance and rebuild the pack.

    Now the pack is back in the car and for the couple test drives the battery is working well. Here is the problem. The gas engine seems to be revving too high for the speed I am traveling. I have another 01 prius so am used to how they sound and drive. It sounds like a car that is not shifting into the proper gear. The only diagnostic gear I have at this point is a cheap universal code reader. I tried a cheap VSI cable but could not get the software to communicate with the cable. I am not a software guy so likely but behind the wheel problem. All the idiot lights are working but off. So the internal diagnostics are happy with the situation. I was able to get live data working and it showed about 4200 rpm at about 40 mph. If it would help I can do more testing of rpm at different speeds.

    The car was doing this same thing while I was limping it home before touching the battery. I also noticed the previous owner had not reset the mpg calculator in the car for over 3400 miles and the average mpg was 34.6 mpg. I know some of that is HV battery but I wonder if this has been running this way for months or years.

    I know nothing about the internal workings of the CVT on this thing or any other transmission for that matter. I am very good at teaching myself how to do things by research and just jumping in where wiser men fear to tread. This thread is the start of my research. Anyone that has gotten this far in a really long post thank you. Any input of what could cause this and the simple stuff to check. I keep hoping it is a sensor or servo. Simple and under budget.

    I do know where I can get a good working used CVT if it comes to that. I have no idea how to do that swap so please throw me your questions of what more info you need or ideas of what to check and how to check it please. Most of what is under the hood is still a mystery to me.
     
  2. Johog

    Johog Junior Member

    Joined:
    Apr 18, 2017
    9
    1
    0
    Location:
    Minnesota
    Vehicle:
    2001 Prius
    Model:
    Two
    Sorry typo in second paragraph. What I meant to say is. I do not know how to figure the amp hours as some talk about in these posts. I do know how to load test petty intensively so while I cannot tell you in mAmp what anything is I can tell you those 38 modules had almost identical properties in charge and discharge time verses voltages. There were many that while not being dead they were not even close to the keepers. There were a few that were too "hot" to match the rest. I am sure I will find a use for those. Maybe an electric bike or lawn mower.
     
  3. telmo744

    telmo744 HSD fanatic

    Joined:
    Apr 8, 2010
    2,168
    764
    0
    Location:
    Portugal
    Vehicle:
    2010 Prius
    Model:
    N/A
    Have you found the reason for the revving? A low HV voltage may drive the engine/MG1 map to "charge" the pack as expected...
     
    Raytheeagle likes this.
  4. Johog

    Johog Junior Member

    Joined:
    Apr 18, 2017
    9
    1
    0
    Location:
    Minnesota
    Vehicle:
    2001 Prius
    Model:
    Two
    No luck yet. The HV battery shows a good charge both on the dash display and volt meter. This is directly tied to driving speed. I have an identical second car. At about 40 mph the good one is about 2200 rpm. This one is over 4000 rpm. It is simply not varying the ratio between the engine and wheels at all.
     
    telmo744 likes this.