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

Help: I saw the "Problem Light" Toyota says there's no code.

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by ultralame, Feb 17, 2010.

  1. ultralame

    ultralame Junior Member

    Joined:
    Feb 17, 2010
    21
    3
    0
    Location:
    SF
    Vehicle:
    2012 Prius c
    Model:
    Three
    My 2007 Prius was in an accident several weeks ago, which required Toyota to remove the engine so that frame and body work could be done.

    I got the car back a week ago. Within 5 miles the PROBLEM exclamation came up and the Engine Temp Symbol displayed. I had it towed back and Toyota said the computer was reporting a "blockage" in the coolant system, probably an air bubble. They drained and re-filled the coolant.

    I got the car back two days ago, but didn't drive it until this monring. 6 miles onto the freeway and I got the same alert message again. I pulled off and had it towed to Toyota.

    This time they said that there is no code in the computer, and that they cannot reproduce the problem. They say it may be an "intermittent" problem with a sticky thermostat, but they aren't sure. Maybe the service would fix it, maybe not.

    So here's the Big Question: Why did the code not show up in the computer? Is it possible that the car reported an engine cooling system problem but not record the code?

    I doubt this. And it worries me. Either Toyota is lying to me or something is really wrong with the computer.

    If you know the answer to this question, please let me know how you know- I don't want to accuse Toyota of lying to me unless that's really the case.

    Thank you!
     
    #1 ultralame, Feb 17, 2010
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,199
    6,464
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    In general, I would say it is a bad idea to accuse anyone of lying to you, especially if you desire to maintain a working relationship with that individual. In the specific case of your car, it is possible for the engine to overheat without producing a DTC.

    The first item that should be checked is the position of the two radiator fans. The fan with seven blades should be on the passenger's side while the fan with five blades should be on the driver's side.

    If the two fans are installed in the wrong locations they will not cool the radiator as intended. When operational, the fans should be sucking air through the radiator, so that will complement (and not fight) the flow of air as you are driving at speed.

    When your tech was attempting to duplicate the engine overheat problem, did s/he drive the car on the freeway? (Probably not.) If the car did not overheat when it was sitting on the dealer's lot, that supports my guess that the radiator fans were reversed when the car was reassembled.

    If the radiator fan positions are correct and your tech thinks that the engine thermostat might be faulty, then it should be replaced. That is a relatively inexpensive repair.

    Although the engine ECU can log several DTC relating to the cooling system, those DTC generally relate to the functionality of the coolant heat recovery system or a problem with the circuitry associated with the engine coolant temperature sensor. There also are a couple of DTC that might be triggered if the engine coolant temp is too low. However there's no DTC if the engine coolant temp is too high, probably because there's an engine overheat warning that appears instead.
     
    #2 Patrick Wong, Feb 17, 2010
  3. ultralame

    ultralame Junior Member

    Joined:
    Feb 17, 2010
    21
    3
    0
    Location:
    SF
    Vehicle:
    2012 Prius c
    Model:
    Three
    Thank you Patrick. I don't want to accuse anyone of lying; but I spent 7 hours at the dealer today trying to get someone (Toyota, the body shop or my insurance) to take responsibility for this. As far as I am concerned, all three are on my S-List from now on.

    FYI, Toyota claims they took it out on the freeway and drove it 18 miles.

    OK- so what you're saying is that the car may have posted an alert to me without logging a DTC, in the case that the coolant got too hot? I see how this could be explained by either the fans being reversed or a bad thermostat. I will ask them to check that tomorrow.

    Thank you!
     
    #3 ultralame, Feb 18, 2010
  4. 2009Prius

    2009Prius A Wimpy DIYer

    Joined:
    Mar 25, 2009
    2,705
    510
    63
    Location:
    USA
    Vehicle:
    2009 Prius
    At least this one should be easy to verify - check the odometer reading. Good luck! :)
     
    #4 2009Prius, Feb 18, 2010
  5. tx'07Prius

    tx'07Prius New Member

    Joined:
    Nov 20, 2010
    1
    0
    0
    Location:
    Texas
    Vehicle:
    2007 Prius
    Model:
    II
    I read this today after returning my 2007 Prius that was in an accident (again!) one week ago. Your story is EXACTLY what I experienced this morning. Has Toyota ever found and fixed your problem????

    I already have an accellaration issue found before they all came out in the news that Toyota never fixed and refused to continue to try to resolve because, "...if it doesn't show up on the diagnostic test...they can't fix it."

    HELP!:confused:


     
    #5 tx'07Prius, Nov 20, 2010
  6. RobH

    RobH Senior Member

    Joined:
    Sep 18, 2006
    2,369
    978
    70
    Location:
    Sunnyvale, California
    Vehicle:
    2006 Prius
    Well, Ultralame hasn't checked in since last February, so I wouldn't expect any closure on his problem.

    Collision damage that requires disconnecting the radiator in order to repair opens up several possible problems. A shop that is inexperienced in Prius repair could easily reverse the fans, and/or not completely bleed the coolant systems. My guess is that something was not properly reassembled. The placement of the cooling fans, routing of the hoses to the thermos, unpurged air in the coolant, or maybe loose/damaged wiring to the temperature sensors.

    You might want to get a ScanGauge and watch the water temperature and inlet air temp.
     
    #6 RobH, Nov 20, 2010
  7. ultralame

    ultralame Junior Member

    Joined:
    Feb 17, 2010
    21
    3
    0
    Location:
    SF
    Vehicle:
    2012 Prius c
    Model:
    Three
    I'm so sorry that I never posted back again...

    Long story short, the body shop never checked or fixed anything mechanical. The issue I was dealing with was *probably* a faulty thermostat. Insurance paid for Toyota to replace it, but we were still dealing with issues (lower gas mileage, wiper pump issues, etc).

    We ended up trading it in mid-2010, which was fine because with two kids we then needed a bigger car anyway.

    We still have the Rav4 we traded in for, and I just picked up a prius c for my commute yesterday.

    Sorry to anyone who was checking this out 2 years ago.
     
    #7 ultralame, Mar 31, 2012
(You must log in or sign up to post here.)