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

Tire Pressure LIght issues?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by shaun5stu, Apr 19, 2010.

  1. shaun5stu

    shaun5stu Junior Member

    Joined:
    Mar 27, 2010
    61
    5
    0
    Location:
    Chandler, AZ
    Vehicle:
    2010 Prius
    Model:
    IV
    Is anyone having issues with the tire pressure light? On my new (< 2000 miles) Gen III, the tire pressure light has come on flashing - indicating there is a problem with the system, not just tire pressure. After about 25 minutes, it goes off. Took it to the dealer once and they didn't find anything wrong (the light wasn't on at the time) and they told me they just added air to the tires.

    It seems to happen to me early in the morning - I leave for work at 5:30 AM. After about 15-20 minutes driving, it starts flashing, then goes off after another 20-25 minutes. Since it's flashing, it's thinking it's not related to tire pressure and/or temperature.

    Two days ago, the same thing happened in my wife's new Prius. Her's came on in the afternoon though, on the way home from work.

    In both vehicles, turning the car off, then on again, makes the light go away.
     
  2. stream

    stream Senior Member

    Joined:
    May 12, 2008
    2,977
    452
    14
    Location:
    Long Island, NY
    Vehicle:
    2010 Prius
    Model:
    V
    Have you checked the tire pressure on both cars, and reset the TPMS? Also the TPMS needs to be activated & initialized as part of the PDI--could be the dealer neglected this process.
     
  3. shaun5stu

    shaun5stu Junior Member

    Joined:
    Mar 27, 2010
    61
    5
    0
    Location:
    Chandler, AZ
    Vehicle:
    2010 Prius
    Model:
    IV
    Well, given that the light was flashing, which indicates a system problem, and not on steady, which indicates a tire pressure issue, I did not try resetting the TPMS. That's my next step, but thought I'd ask here first.
     
  4. stream

    stream Senior Member

    Joined:
    May 12, 2008
    2,977
    452
    14
    Location:
    Long Island, NY
    Vehicle:
    2010 Prius
    Model:
    V
    See attachment for activation & initialization that should be performed as part of PDI. Since both your new Priuses are experiencing the same issue (and presumably you bought them from the same dealer), I'd ask the dealer to perform this.
     

    Attached Files:

  5. shaun5stu

    shaun5stu Junior Member

    Joined:
    Mar 27, 2010
    61
    5
    0
    Location:
    Chandler, AZ
    Vehicle:
    2010 Prius
    Model:
    IV
    Good point. Both were purchased from the same dealer, although one was shipped from another dealer a ways away. Still, I'll have them re-initialize the system next time I bring the car in.
     
    1 person likes this.
  6. wick1ert

    wick1ert Senior Member

    Joined:
    Dec 3, 2009
    1,311
    183
    2
    Location:
    Delawhere
    Vehicle:
    2010 Prius
    Model:
    III
    Could potentially be bad TPMS sensors somewhere in the car. Maybe battery going dead in one? Seems odd to happen in both vehicles at the same time and being so new.

    Of course, the above is taking into account the assumption that the activation & initialization was performed originally.
     
  7. shaun5stu

    shaun5stu Junior Member

    Joined:
    Mar 27, 2010
    61
    5
    0
    Location:
    Chandler, AZ
    Vehicle:
    2010 Prius
    Model:
    IV
    I'm 99% sure I found the problem. Page 444 of the owners manual states: "If the ID code of the tire pressure warning valve and transmitter is not registered, the tire pressure warning system will not work properly. After driving for about 20 minutes, the tire pressure warning light comes on after blinking for 1 minute to indicate a system malfunction."

    This is exactly the behavior I am seeing. I'm dropping it off at the dealer Saturday to get it fixed.
     
    1 person likes this.
  8. Carnutt

    Carnutt Member

    Joined:
    Jun 11, 2008
    232
    23
    0
    Location:
    SW USA
    Vehicle:
    2018 Prius
    Model:
    Four
    Where is the tire pressure reset button? I looked at the diagram in the manual but my car has no switch there :eek:?
     
  9. shaun5stu

    shaun5stu Junior Member

    Joined:
    Mar 27, 2010
    61
    5
    0
    Location:
    Chandler, AZ
    Vehicle:
    2010 Prius
    Model:
    IV
    Took it back to the dealer yesterday. They checked the error codes, reset the codes, and re-initialized the system. Said they left the car on for over 30 minutes and the light did not come on. The real test will be when I drive it to work tomorrow.
     
  10. stream

    stream Senior Member

    Joined:
    May 12, 2008
    2,977
    452
    14
    Location:
    Long Island, NY
    Vehicle:
    2010 Prius
    Model:
    V
    It's under the dash, near the steering column. It's hard to locate by feel--look under the dash in the location shown in the owners manual--it's a very small button.
     
  11. shaun5stu

    shaun5stu Junior Member

    Joined:
    Mar 27, 2010
    61
    5
    0
    Location:
    Chandler, AZ
    Vehicle:
    2010 Prius
    Model:
    IV
    Sad to say, but my tire pressure light came on again this mornign :-( Same behavior as before I took it to the dealer.
     
  12. amm0bob

    amm0bob Permanently Junior...

    Joined:
    May 29, 2008
    7,730
    2,547
    0
    Location:
    The last place on earth to get cable, Sacramento
    Vehicle:
    2008 Prius
    Model:
    II
    I had a bolt stuck in my tire... I'd put in some air... the light went out...

    I did that 4 times and went to the dealer... they put air in the tires and reset the system...

    The next day the light came on again... I took it to Americas Tire Store on Arden and told em I think I had a leaker in the front... they pulled the tire off and sho-nuff... there's the problem...

    The dealer didn't find it.

    It hasn't come back on for 2000 miles, so I think it's OK now.
     
  13. bedrock8x

    bedrock8x Senior Member

    Joined:
    Jul 8, 2008
    1,483
    137
    0
    Location:
    California
    Vehicle:
    Other Hybrid
    Did you check the tire pressures when the light comes on?
     
  14. shaun5stu

    shaun5stu Junior Member

    Joined:
    Mar 27, 2010
    61
    5
    0
    Location:
    Chandler, AZ
    Vehicle:
    2010 Prius
    Model:
    IV
    It wasn't a tire pressure issue. The light came on after 20 minutes of driving and it was flashing. This indicates a problem with the montioring system, not a tire pressure issue, per the manual. The behavior I was seeing was described EXACTLY on page 444 of the manual, where it describes how the system behaves when it has not been initialized.

    I have not seen the light come on again, so perhaps it was finally fixed.
     
  15. wentfrom15to51MPG

    wentfrom15to51MPG New Member

    Joined:
    Nov 26, 2009
    10
    5
    0
    Location:
    Little Rock, AR
    Vehicle:
    2010 Prius
    Model:
    II

    I have had a similar problem with my 2010 Prius II. The dealer reset the light twice, re-initialized the system on the third trip and now have kept my car for 2 weeks and can't seem to fix the problem. They called last Friday to tell me they are considering ordering a new computer for my car. Which computer? I do not know. Why it is taking 2 weeks or more? I do not know that either. Very frustrated by Toyota and would really like to just mitigate my losses and get rid of this car at this point. Too bad.
     
  16. shaun5stu

    shaun5stu Junior Member

    Joined:
    Mar 27, 2010
    61
    5
    0
    Location:
    Chandler, AZ
    Vehicle:
    2010 Prius
    Model:
    IV
    An update: I've been having this problem on and off since I first got the car - almost 18,000 miles ago. It's been back to the dealer 7 times to get fixed. On the eight time, after filing a complaint to get the car replaced under my state's lemon laws, they discovered the problem: Interference with the tire pressure sensor signals from the LEDs I used to replace the license plate lights. More details in this post. Just wanted to get this out there for future reference. I never would have suspected LEDs could cause interference with RF signals (and I'm an electrical engineer), but apparently they can.
     
  17. shaun5stu

    shaun5stu Junior Member

    Joined:
    Mar 27, 2010
    61
    5
    0
    Location:
    Chandler, AZ
    Vehicle:
    2010 Prius
    Model:
    IV
    They replaced the tire pressure computer in my car too, but that didn't fix it. Would be interested to know if you replaced the license plate bulbs with LEDs. That was the cause of my problem.
     
  18. jrlnc

    jrlnc Junior Member

    Joined:
    Aug 28, 2009
    56
    8
    0
    Location:
    Piedmont, NC
    Vehicle:
    2010 Prius
    Model:
    Two
    My 2010 Prius isn't even 4 weeks old yet and I am constantly having this problem too!

    My tire pressures are good. I have done the TPMS warning reset at least 3 different times (followed the owner's manual) and it has been back to the dealer twice.

    It exhibits the same behavior you described. It starts flashing after 20 mins of driving then stays on. It's going back to the dealer this Saturday. If it starts doing it again after that, I start talking to Toyota.:mad:

    btw, I haven't installed any after-market LEDs or other items.
     
  19. shaun5stu

    shaun5stu Junior Member

    Joined:
    Mar 27, 2010
    61
    5
    0
    Location:
    Chandler, AZ
    Vehicle:
    2010 Prius
    Model:
    IV
    As an FYI, Toyota also investigated a couple other areas with me: 1) window tint. I have ceramic window tint, so that wouldn't interfere with RF signals, but if you use metallic tint, it might. 2) Cell phone charger - plugs into electrical system. A cheapo model might send feedback into the electrical system. 3) my daily commute - did I drive by any high-power radio or cell antennas. (Personally, I think they were grasping at straws with this one.) Basically, check your car for anything you might have added that could block radio signals or that connects to the electrical system (which could cause feedback).

    Since your light is flashing, it's not a tire pressure issue, so resetting the system won't do anything. It's a system issue. Can you determine any pattern to when it happens (other than after 20 minutes)? For instance, is it only happening when your lights are on? When it's below or above a certain temperature? When you are in a certain part of town?

    I was also getting very frustrated, but just be patient. Toyota really was fantastic with me. Check your state's lemon laws. In Arizona, you have to give the dealer 3 or 4 chances to fix it. If they can't, then you can file a claim. Actually, there is a handbook that comes with your manual that details what to do if you want to file a claim. Forome states, like Arizona, Toyota requires that you file an arbitration request first. The nice thing is that the arbitration results are binding on Toyota, but not you, so if you don't like the results, you can still go to court for a new car. But I would recommend going down that route. It gets their attention and it's no cost or harm to you.

    Document every time you've taken the car in to get this repaired. Use https://auth2.toyota.com/owners/apps/mytoyota/auth/ssl/OwnersLogin.do. This will let you access the dealer's records for you car. I used the info from here when I filed my arbitration claim to document repair attempts.
     
  20. cycle11111

    cycle11111 New Member

    Joined:
    May 6, 2010
    145
    10
    4
    Location:
    McKinney, Texas
    Vehicle:
    2010 Prius
    Model:
    IV
    Mine used to do it but after I reset the TPMS as per the manual and also have been more diligent on actual tire pressure it has not come on for about 5K miles