Saga of Prius Prime Flat

Discussion in 'Prime Main Forum (2017-Current)' started by JTEM, Apr 12, 2020.

  1. JTEM

    JTEM Member

    Joined:
    Oct 9, 2017
    55
    34
    0
    Location:
    Boston, MA
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    So here goes.

    I had not used my Prius Prime for a week or so. Headed out to load up on (non!) essentials at local warehouse store. On the highway felt the car handling funny. Since it was very windy figured that was the reason. Since the exit was close and the warehouse just a half mile down, pulled into its parking lot. Lo and behold left rear tire was essentially flat.

    Topped up air in the warehouse for free. Air seemed to continue to leak out. So found the Toyota flat repair kit. Turned the car back on. Hooked it up to the 12V outlet and filled the flat with the solution that the kit comes with. Disconnected the repair kit. Pressure seemed to be holding. Car stayed powered on, and lights were on. Went in to the store to pick up the order.

    Got back and found the missus fiddling around in the driver's seat. Apparently she noticed some alerts on the dashboard and then power seemed to go. Tried turning lights on, etc., but to no avail. Got an alert about failure of the ABS system.

    Called the AAA service and they dispatched a technician to jump the car. Car powered on, but the check Engine light came on. I dropped off the car at the Toyota dealership a mile away. Now waiting to hear what they have to say. My suspicion is that the flat repair kit draws a lot of power from the 12V battery and some threshold was crossed for the 12V battery. Quite strange if you ask me. The 12V battery should have been fully charged because I drove the Prime ~ 10 miles from home to the store.
     
    bisco likes this.
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    91,799
    41,413
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    bummer!
    was the car in ready when you used the inflator?
     
    Mendel Leisk likes this.
  3. FuelMiser

    FuelMiser Senior Member

    Joined:
    Jun 29, 2008
    940
    657
    0
    Location:
    Monument, CO
    Vehicle:
    2016 Prius
    Model:
    Touring
    No TPMS warning? Doesn't change the outcome, but perhaps it was on when you started the car and you didn't notice it. Not sure about the Prime, but the TPMS light on my hatchback is way out of the driver's normal line of sight at the right side of the display, which is already in the center of the dash. There is a warning beep that accompanies it, but maybe masked by other sounds when powering on.
     
    #3 FuelMiser, Apr 12, 2020
    Last edited: Apr 12, 2020
  4. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    12,033
    8,730
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    When you say "car stayed powered on", was it in READY (word READY showing in the instrument cluster), or just ON (instrument cluster lit up but no READY)?

    ON mode will flatten your 12 volt battery in short order, with or without the inflator. There's a lot of stuff in the car drawing power in ON, and nothing putting it back.
     
  5. JTEM

    JTEM Member

    Joined:
    Oct 9, 2017
    55
    34
    0
    Location:
    Boston, MA
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    Car was in the ON mode and not in the READY mode when I used the inflator.

    BTW, I had 16+ miles of range in the hybrid battery. Why did the inflator not draw power from the hybrid battery as opposed to the 12V battery?
     
  6. jzchen

    jzchen Senior Member

    Joined:
    Apr 9, 2012
    2,155
    669
    0
    Location:
    Arcadia, CA
    Vehicle:
    2012 Prius v wagon
    Model:
    Five

    It’s just designed that way. Need the READY mode for the power to come from the hybrid battery, then when hybrid battery is depleted the engine.
     
    JTEM likes this.
  7. Trollbait

    Trollbait It's a D&D thing

    Joined:
    Feb 7, 2006
    16,465
    7,734
    0
    Location:
    eastern Pennsylvania
    Vehicle:
    Other Non-Hybrid
    ON is equivalent to turning the key part way in a traditional car to keep the radio on.

    There is a physical switch to the traction battery that is only on when the car is in READY.
     
    JTEM likes this.
  8. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    12,033
    8,730
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    Cars usually have a position called ACCessory that only powers the radio and maybe one or two other things, and also one called ON where most stuff in the car has power, but the power isn't being replaced.

    Prius is the same. ONE button push without the brakes is ACC, and you can play the radio, plug stuff in the power outlets, etc. TWO pushes without the brake and most stuff in the car is powered (instruments, computers, HVAC blower, coolant pump(s) depending on generation, etc.) and none of that power is being replaced.

    For the power to be getting replaced, the conventional car needs to have the engine started; the Prius needs to be in READY.
     
  9. MikeDee

    MikeDee Senior Member

    Joined:
    May 9, 2013
    1,162
    432
    0
    Location:
    San Francisco Bay Area
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Plus
    You may have a weak 12v battery. Make sure the dealer tests it.
     
    JTEM likes this.
  10. JTEM

    JTEM Member

    Joined:
    Oct 9, 2017
    55
    34
    0
    Location:
    Boston, MA
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    Thank you very much for the responses. Now waiting to hear from the dealer on the Check Engine Light.
     
  11. The Electric Me

    The Electric Me Go Speed Go!

    Joined:
    May 22, 2009
    9,083
    5,775
    0
    Location:
    Undisclosed Location
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    I think the OP's suspicion that using the repair kit, weakend the 12 volt- probably a good bet.
    There's so many benefits provided by driving a Hybrid and a Prius with HSD, but perhaps one drawback of the system is that since the Prius doesn't crank over the engine like a regular ICE, and doesn't have an alternator, it's harder to gauge or get warning the 12 volt is weakening.
    When I owned my Prius, I just avoided using any accessories designed to be plugged into the AC socket. I bought a portable, but household chargeable unit that was a jumper/tire inflation and stand alone AC power unit. Maybe unnecessary, but with a Prius, and all the electronics, gave me piece of mind that I didn't have to tap the system in most cases.
     
  12. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    91,799
    41,413
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    you have to be in ready mode for the car to use the hybrid battery, and/or the engine. on mode just depletes the 12v.
    the check engine light is just from the low 12v.
     
    Mendel Leisk likes this.
  13. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    12,033
    8,730
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    Being in ON mode for that long would have been hard on the 12 volt battery whether or not the inflator was used. Just remember all the other equipment in the car that is powered up and consuming power when ON.
     
  14. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    91,799
    41,413
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    doesn't gen4 have auto shut down?
     
  15. Tideland Prius

    Tideland Prius Moderator of the North
    Staff Member

    Joined:
    Oct 2, 2004
    42,269
    13,802
    41
    Location:
    Canada
    Vehicle:
    2018 Prius Prime
    Model:
    Technology
    It's a 20 min timer though.
     
    bisco likes this.
  16. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    91,799
    41,413
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    still no low 12v cutofff, amazing.
     
  17. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
    9,495
    11,591
    0
    Location:
    Tampa, FL
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    But there IS a cut-off. As @Tideland Prius said, it's 20 minutes.

    Here's how I handled my tire issue a few months ago. It was about as carefree as you could ask for.
    • I was starting out on an errand about 20 miles away (40 mile round trip). I almost always take a quick look at the tires before I get in the car. They looked OK. Looks can be deceiving.
    • After a few miles, I noticed that pesky tire pressure warning. They all looked roughly the same. Had to use the tire pressure gauge. Found that the left rear was down to about 28 psi or something like that. I opened the back seat arm rest storage and took out my 12V pump. (The OEM slimy POS is in a drawer in my garage pending the eventual day when I trade or sell the car.)
    • I left the car in READY and pumped up the tire. Then I finished my errand.
    • When I got home, I jacked up the left rear so I could spin the wheel and found two little pieces of wire that were smaller than a pencil lead. Some spit confirmed that they were the culprits.
    • I marked the tire with chalk, called the shop to see if they could fit me in. They said yes.
    • I took the car over there and they patched it under the road hazard warranty while I took a walk and looked at the new cars.
    • Total cost was $0 plus a change in when and where I took my walk that day. Doesn't get much easier.
    The secret sauce was having a regular pump, keeping the car in READY when using it, and having a spare tire if worse comes to worse.

    Now, had there been a blowout or a sidewall puncture, then I'd have had the added chore of removing the tire and putting on the donut spare I keep strapped in the cargo area. But I've changed gobs of tires and it's not that big of a deal.
     
    MTN likes this.
  18. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    91,799
    41,413
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    right, i mean before the battery gets too low. it ain't hard to kill these cheesy little batteries very quickly
     
    jerrymildred likes this.
  19. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    14,645
    8,092
    90
    Location:
    Western Washington
    Vehicle:
    2012 Prius
    Model:
    Three
    I don't know if Gen4s and Primes are different, but Gen3's charge their 12V surprisingly slowly. 10 miles does very little, it takes many hours, e.g. an all-day drive, to reach full charge.
    It is part of the safety design to protect both auto mechanics, and first responders who may have to cut the car apart. Unless the car is in READY, the hybrid battery is electrically disconnected, inside the battery case!, from the rest of the car.
     
  20. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    12,033
    8,730
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    Gen 3s will recharge the 12 volt faster than gen 1s and gen 2s.

    The Gen 1 and 2 charging voltage maxes at around 13.8, which rarely translates into more than a few amps going into the battery. Take a 45 amp hour battery and that's over ten hours for a full charge.

    Gen 3 charging voltage can go up to 14.7 or so, and produce double-digit amps into the battery, at least early on and if the battery is quite drained. AHetaFan measured it here. (Gen 3 also has a temperature sensor above the battery, to avoid overdoing it.)
     
Loading...