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

12 Volt battery replaced. Now engine idle at 1640 RPM

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by 1fixitman, Sep 20, 2012.

  1. 1fixitman

    1fixitman Member

    Joined:
    Jun 26, 2007
    182
    4
    0
    Location:
    Augusta, GA
    OK. I drove the Prius to work last night and got a few codes on the way to work. I didn't have my Auto Enginuity laptop in the vehicle for the drive in. I did get a CEL(Check Engine Light) on the way to work. It still idled between 1520 and 1600 RPM no matter what the SOC of HV batt or coolant temp. My coolant temp usually runs between 180-203 deg F. The cooling fan starts running at or near 203. I had the following codes when I checked with AE this morning.
    Po441 Evap Emission Control sys Incorrect purge flow
    P0446 Evap Emission Control sys Vent control valve circuit
    The valve is just to the left of the throttle body and I will check it's operation in the near future with a 9 volt battery.
    I really don't want to replace the canister. These two codes have nothing to do with my car not going into golf cart mode.
    P0505 Idle Air Control System.
    I ran the car at low speed when I read codes with AE because the HV battery was down to two bars since the car was constantly running at 1600RPM and the Engine Coolant temp was hovering near 202-204 deg F.
    I drove about 35MPH for two and a half miles with ambient temp at 67 degrees so the engine cooled down to 180 quickly and the SOC went back to the normal 6-7 bars of charge.

    I really had nothing to loose at this point so I cleared codes in a Krispy Kreme parking lot. When I cleared codes my idle was 1600RPM and the coolant temp was 185 deg F. Immediately the engine idle went to 0 RPM with the Engine timing angle at 5 degrees and the CEL cleared. Yeah! It finally went into golf cart mode. So my 1260$ investment into AE SP01 with Enhanced reading has paid off. I did purchase a dell inspiron 1100 for 50$ from a guy on craigslist just for the AE software. I really purchased AE for my F250 7.3L Turbo diesel but I didn't just buy the ford bundle for 360$ because I own the Prius also. I have only had the program for three weeks.

    I do not think I am out of the clear on the P0441 and P0446 codes though as they will come back soon enough.

    I will do a similar cleaning of my Idle Air Control Motor/Valve and air ports in the very near future just in case it is starting to get dirty. Here is a video of a guy doing a truck. He is extremely detailed and confident.

    The systems are very similar. The IACM/V on the Prius is just to the right side of the TB(Throttle Body) and below the plastics that house the Air filter. I need to go pick up some TB cleaner.

    Like I said earlier, I still need to address the P0441 and P0446 codes.
    Thank you for all of your comments and help. I will keep my eye on any further CEL or DTC's. This is a true hurrrrraaaaayyyy for not having to open my wallet to the Stealership.
    Dwayne
     
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,198
    6,461
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    The repair manual suggests that you check the PCV valve hoses and the intake air induction system for any leaks. Also make sure that the engine oil cap and engine oil dipstick are secure.

    If you don't have any problems there, then the manual suggests that you perform a variety of checks, such as holding the throttle plate open manually, and checking to see that the engine ECU recognizes the throttle position is 60% or more.
     
  3. 1fixitman

    1fixitman Member

    Joined:
    Jun 26, 2007
    182
    4
    0
    Location:
    Augusta, GA
    Unfortunately I am back. When I shut the car off this morning everything was operating correctly. I drove to work this evening and the 1600 RPM idle is back again. My drive to work involves interstate driving and city driving. Just as I pulled into the parking lot at work this evening, a 17.5 mile ride from my home, the CEL came back on. I have the scanguageII in the vehicle but I did not check the code before I clocked in. I will have to wait until tomorrow morning to look further into this. It is really iritating but I have a great resolve to not take it to the dealer.
    To the person that asked if the coolant pump had been replaced. Yes, I let the dealer replace the pump when I had them replace my transmission fluid at about 81K.
    Currently, if I open the cap for the Inverter Cooling system while the engine is running, I see turbulent flow in the bottle and the temp on the inverter is warm to the touch but not hot. I replaced one of the cooling hoses for the ENGINE cooling system in 2007 when I purchased the car and I also replaced a vent for the inverter cooling system at that time since it was leaking and performed the proper venting on the system at that time. It has been 5 and a half years since I did that so I think I would have seen an issue with it by now if it was an issue.

    To the Gal who wants to know about her 12 volt battery...If you follow this procedure you can check your 12 volt battery voltage without using a meter.
    1. Hold the display button in on the Multi Function Display (MFD) with the vehicle turned off and do not let go.
    2. Keep your foot OFF OF THE BRAKE and with your key FOB in the vehicle(smart key) or inserted in the dash Press the POWER button one time. This will take your MFD to a different setup mode.
    3. Keep holding the display button in and switch your driving light switch to the fog/auxilary position and then back to off three times in a row within about 8-10 seconds (not to the lights full on position which is the second position on the switch)
    4 Now you can let go of the display button on the MFD.
    5. On the new screen that you have never seen before push the MENU button.
    6. On the next screen push the DISPLAY CHECK button.
    7. On the next screen push the VEHICLE SIGNAL CHECK button.
    You are now looking at a screen that will show you your 12 volt battery voltage.
    Is it less than 12 volts??
    Mine was about 9.4 volts which is why I changed the 12 volt battery.
    You can also check the engagement of your Emergency brake here and your tail lamp switch for your regular brake lights if you hold them long enough. If you push your brake pedal at least three times fully, your brake pump will cycle and you can watch your 12 volt battery voltage drop a little. This is one way to do a small load test. Mine dropped further to 8.9 volts when I did this.
    You can Place your foot on the brake and push the power button to get the MFD and car back to normal operation at any time.
    You can hold the display button in with the car in normal operation and cycle the light switch three times again to go thru the same steps as before to now look at what voltage the inverter system is supplying to the battery. Is the voltage between 13-14 volts now? If it is then it is charging your battery properly.

    I hope this helps in your battery games. I am still looking for my issue. I am still open to any comments. Thank you for your help so far. Does anyone know where the evap cannister is for the fuel system?? Is it near the fuel tank at the rear of the vehicle. Do you know of any standard issues with this vehicle for that system? I know where the solenoid is, to the left of the throttle body under the inlet to the air cleaner. I know there is no leaby with no power but I need to power up that solenoid valve and check that air is flowing from the canister. I am sure I am going to have really crappy fuel economy this tank. I usually have 43-46 MPG most tanks. This tank fill cycle is at 30.3 MPG with only 120 miles on this tank. Joy. Joy.
    Dwayne
     
  4. bob749prius

    bob749prius Junior Member

    Joined:
    Apr 20, 2008
    33
    2
    0
    Location:
    Venice, FL
    Vehicle:
    2018 Prius
    Model:
    Four
    I see that Optima makes a "Pruis Friendly" battery for about $200. My 2008 is doing great just with oil changes and trying not to do anything "stupied". Just got new tires from Tire Rack; Brigstone. Excellent price (with rebate) and gas mileage from the start BUT quality of tires not like other well known top brands. At 4 years, I'm going to change the 12V battery and I'm trying to decide to buy Toyota or go with Optima. It appears if one can do it him/herself IF you go slow and not try to rush (I like to rush). Any Advise????
     
  5. srivenkat

    srivenkat Active Member

    Joined:
    Feb 28, 2011
    596
    91
    0
    Location:
    IL
    Vehicle:
    2021 Prius Prime
    Model:
    XLE
    [underlined and emphasized "after" for the below question]

    Did you mean to say "before" here? I heard people usually recommend doing the techron tank additive right before an oil change so anything that gets into the oil will get drained out.
     
  6. SteveLee

    SteveLee Active Member

    Joined:
    Sep 15, 2012
    645
    179
    0
    Location:
    North Carolina
    Vehicle:
    2010 Prius
    Model:
    I
    I'm thinking it should be used a couple of tanks of gas before an oil change....which would be after the previous oil change. ;)
     
  7. 1fixitman

    1fixitman Member

    Joined:
    Jun 26, 2007
    182
    4
    0
    Location:
    Augusta, GA
    I know it has been a while since I posted but I am still back here to explain what I did. The Throttle Body was toast. the cost from the dealer was 1100$ installed. I hated to do it but I needed to drive my car.
     
  8. srivenkat

    srivenkat Active Member

    Joined:
    Feb 28, 2011
    596
    91
    0
    Location:
    IL
    Vehicle:
    2021 Prius Prime
    Model:
    XLE
    Did you consider a used replacement from ebay and replacing it yourself or by a private garage?
     
  9. 1fixitman

    1fixitman Member

    Joined:
    Jun 26, 2007
    182
    4
    0
    Location:
    Augusta, GA
    My throttle body TPS sensor was bad and the TB would not adjust. I had been working 6 and 7 days a week at 32$/hr straight time and 48$/hr on Overtime. I did not have much time in my schedule to make that happen. The dealership had it done along with a transmission fluid change in about two hours. I could have saved a few hundred bucks but if it did not work with a used one then I would have had more vehicle down time and loss of wages from not being able to get to work. In my situation at the time I believe it was worth the money I paid. Think about it. Two and a half days of overtime paid for the repair.
    Work was a 12.5 hour shift plus the ride to and from work. If I had to do it again in the same situation I would have the stealership do it again. It all comes down to time and money management. Most folks would not or could not have paid it. I had the money and very little time.