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Can check engine / red triangle be caused by low oil?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by miked983, Dec 22, 2008.

  1. miked983

    miked983 New Member

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    Hello,

    I had a problem a few months ago where someone left the light on in my Prius overnight. When I found it, the car was completely dead, couldn't start it or anything. After a lot of runaround, I ended up replacing the original, now dead, battery with the Miata battery from elearnaid. Once I did, the car started up, but I had a red triangle, check engine light, and the MED had the car-with-exclamation-point highlighted. In addition, the gas engine wasn't coming on and the car would only drive very slowly. I was frustrated with this for awhile, but read somewhere (I believe here) that if you drive it around, it'll charge the main battery up and that can get the problem to go away.

    Well, against my better instinct, I tried that method, and it seemed to work. I had problems for a week or so where sometimes I'd start the car and it'd give me those errors again, but I'd drive it for a few minutes, restart the car a few times, and it'd go away. After a while, I stopped getting the errors completely.

    Well, a week or so ago I drove back home and now have my car parked outside instead of in a garage. Now I'm getting the red triangle + check engine every time I turn on the car - even if I drove it and charged it the day before. It's pretty consistent. Now, I haven't had the oil replaced in a long, long time - definitely too long. I checked it the other day after driving for a while and it was a bit low. The fact that the car is parked out in the cold all the time now makes me think that it might be reading the oil level as even lower when it first turns on. The fact that I've only been having these problems again since I got home, and that it is so consistent, makes me think there might be a corollary.

    Anyways, the car is under warranty still, and so I could bring it in to the dealer to have them work it out, but I'm worried that they'll try to void my warranty because I replaced the battery with a non-standard one. Because of this, before taking it in to the dealer, I'd most likely have to get a new auxiliary battery that is kosher with Toyota. Since we all know that this is an expensive option, and since time is of the essence for me anyways, I was curious to know if these errors could be caused by low oil. I'd really rather not believe that the electronics just all of a sudden decided to start acting up, especially since this whole battery issue has been a huge headache and I don't want to open up that can of worms again. If I haven't mentioned, it is a 2002 Prius. Thanks in advance for any replies.

    -mike
     
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Hi Mike,

    I would not worry about the 12V auxiliary battery being an issue regarding your warranty entitlement.

    My guess is that your problem is DTC P3191 "engine does not start", that this is unrelated to the dead 12V battery problem, and the cause of the problem is that you need the engine ECU to be updated to the current revision. So if your odometer has less than 80K miles it would be good to have your dealer check out the problem and install the current ECU if applicable, under the Federal emissions warranty.
     
  3. john_dough

    john_dough New Member

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    Patrick--could you list exactly the things that the aux battery does? For example, does it start the ICE? Thanks.
     
  4. miked983

    miked983 New Member

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    I'm with you on the warranty thing, I'd rather just take it in as it is and let them deal with it. As far as I'm concerned, a battery's a battery - I seriously doubt that it is the source of the issues and I wouldn't believe them if they tried to write it off as that. Still, it's up to my parents, though, and I wasn't able to prove to them that we wouldn't be liable.

    As for the ECU, I never had any such warning lights or problems before that first battery died. It seems strange that these problems would develop on their own concurrently. Can battery problems develop latent issues in the engine or is this just a common problem or something?

    Sorry, just trying to satisfy my curiosity :)

    edit: pretty sure the aux just powers the computer components. main battery turns on the ICE iirc.
     
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Hi Mike,

    DTC P3191 is a common problem with older Classic Prius. Over time as the engine ages and gets out of tune, it takes longer to start. The engine ECU allows a certain amount of time to pass before giving up on the engine starting and logging the DTC. The current revision ECU allows more time to lapse before logging the DTC.

    If your car was out of warranty then I would advise making sure the engine is in tune by replacing the iridium spark plugs and engine air filter, and cleaning the throttle body. That might be enough to prevent the warning lights coming on.

    You had previously asked about engine oil level. That would not cause the warning lights to come on unless the oil was so low that the engine seized up. If the oil viscosity is thicker than 5W-30 that can cause engine start problems in the winter.

    Hi John,

    The 12V auxiliary battery's function is to provide power to start up the various Prius ECUs and power the brake pressure accumulator pump. Around 30A peak current is required from the battery before the Prius becomes READY. Once the Prius is READY the DC to DC converter within the inverter will produce 13.8V to power the 12V bus and also recharge the auxiliary battery.

    The Prius ICE is started when the hybrid vehicle ECU commands MG1 to spin up. That motor is powered by the large traction battery via the inverter, whose function is to change the traction battery DC (273VDC for Classic and 202VDC for 2G) to three-phase AC (273VAC for Classic and 500VAC for 2G) to power the motor.
     
  6. qbee42

    qbee42 My other car is a boat

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    What sort of warranty can you have on a 2002 Prius? That seems a bit old.

    Changing the battery will not void your warranty. Not changing the oil will.

    This entire post sounds funny to me. Not quite troll-like, but something is definitely odd about it.

    Tom
     
  7. miked983

    miked983 New Member

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    The warranty is a "Platinum" warranty - it lasts until next year I believe. The car was originally under warranty when there was a problem, I believe, with the transmission or drivetrain. I wasn't using the car at this point so I'm not sure. My parents took it to the dealership and they fixed it. This was maybe a year or two ago, so I wouldn't be surprised if the warranty was extended or at least altered after they did this work on it. The warranty is through the dealer, not the manufacturer.

    It's not like the oil has never been changed in the car, but I use it very infrequently to make either short trips to the supermarket or long trips from socal (where I go to school) to norcal (home). I should've checked it in November, but forgot, not that I drove it much anyways, and when I looked at the dipstick the other day, it appeared to be low. I figured that the oil volume probably depends on temperature, so I thought there might be a corollary between how much colder it is up here and the sudden onset of problems - go figure, there isn't.

    Changing the battery shouldn't void the warranty, I agree. I seriously doubt that the battery caused or is causing any problem. However, I do know that car dealers are about as slippery as eels, and I wouldn't be surprised if, if there is some sort of problem with the electric systems in the car, they try to pin it on the non-standard battery to get out of paying for the costs. I don't know why you think I sound like a troll, whatever that is, but I'm not yanking anyone's chain. I may be pretty out of the loop when it comes to cars, but these are real problems that I've been dealing with for months.

    I even made a post here in October when I first installed the battery:
    priuschat.com/forums/care-maintenance-troubleshooting/54534-another-12v-battery-problem-02-prius.html
     
  8. john_dough

    john_dough New Member

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    Patrick--thanks for the clear explanation. I've been wondering about that. Thanks again.
     
  9. miked983

    miked983 New Member

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    Dealer fixed it - turned out to be a problem with the mass air flow sensor. Also turned out that my warranty had actually expired in May so it ended up costing me $700. Makes me wish I had been trolling....

    edit: Can't forget - thanks for the accusations, thread derailment, and, of course, help. :D
     
  10. Patrick Wong

    Patrick Wong DIY Enthusiast

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  11. donee

    donee New Member

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    Hi Miked...,

    Many cars have MAF's, and they require repair on occiasion. Not a Prius thing.
     
  12. jayman

    jayman Senior Member

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    Hot wire MAF's also require cleaning too. My FJ started acting a bit weird this summer. A dirty hot-wire MAF can even cause an automatic transmission to shift funny

    I used an approved cleaner to clean my FJ MAF, and the difference in performance was day and night. Just like the Prius, my FJ also appears to put deposits in the intake. My only theory is that the PCV operation is putting oil vapor into the intake, where it gets cooked onto the MAF wires

    BTW here is a link to an approved MAF cleaner

    http://www.crcindustries.com/files/MAF%20Sell%20Sheet%20Web.pdf

    It's called Sensor Kleen in Canada
     
  13. andyprius

    andyprius Senior Member

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    Hello Jay again, I just bought some of that stuff and simply sprayed the top. The can says to remove the sensor and spray thoughly. What do you think on that. Can a accumulation of dirt and oil be on the bottom of the sensor. I havn't checked my Bentley yet to look at removal. Nothing in Bentley.