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help!! "Drive Motor B" code, stuck 12 hours away from home

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by VisualMonster, Jun 25, 2011.

  1. VisualMonster

    VisualMonster New Member

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    Need some advice, my wife and I are on a 2400 mile cross country road trip road trip and we just got a check engine light about 12 hours away from home. The check engine light, VSC, and tons of other lights appeared. Shortly after our cruise control disengaged and then A/C stopped blowing cold air. We were cruising along in 100F degree weather at about 75-80mph climbing a 10 mile incline with the AC on full blast.
    We got to a toyota dealership but they are closed until Monday so we'd have to wait 2 days for them to check it out. We went to pep boys and they found the code to be "Drive Motor B" which they said should be fixed by Toyota dealership (but he said he didn't really know what the issue is).
    I did a quick search and found this might be the inverter coolant pump. Like another poster, I found the car seems to work okay when the AC is off.

    Is anyone familiar with issue? Right now we are trying to decide if we should try finishing our 12 hour road trip with the AC off (we still have a lot of elevation to climb) or if we should stay in a hotel for 2 days and have the Toyota Dealer check it out on Monday (we were hoping to avoid this since we both have work on Monday). We want to get home right away but also don't want to get stranded on the side of the road 12 hours away from home in the middle of nowhere. Thoughts on this? I have no idea how severe this code is.
     
  2. cwerdna

    cwerdna Senior Member

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  3. northwichita

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    When the electrical systems fail, any codes are generally suspect , the voltage drops and strange things happen.

    Check the coolant pump reservoir for turbulence with the car in Ready.

    If it is the coolant pump failure, most would probably say don't risk the drive, you could be stranded , say in the 100 degree Midwest..
     
  4. VisualMonster

    VisualMonster New Member

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    He told me the code is "Drive Motor B", he didn't give me a number code though. It's a 2005 Prius with 85,000 miles and it hasn't had the inverter water pump work done, I didn't even know there was a tsb on this until now. Too make this even worse, I found there isn't even any hotels available in the area since everything is booked up already. ugh...

    Would I risk doing expensive damage to the car if it turns out to be the inverter water pump? i'm still calling around for hotels, but as it is i'm looking at $500 of hotel costs (I guess there is a big local event going on in this city) plus two wasted days 1200 miles away from home. :(
     
  5. VisualMonster

    VisualMonster New Member

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    I haven't really payed attention to the coolant pump reservoir while the car is in ready, is the turbulence easily visible? Does car in ready mean to press the power button twice or is that when it is completely ON (using brake pedal)?
     
  6. northwichita

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    Yes, just like you're going to drive off., but have the car in Park.

    Take the cap off of the reservoir and look inside, its a very low pressure system.

    It should slightly gurgle, like a fish tank filtering system .

    I'm reminded of another thread, if it is the inverter coolant pump failing, of the suggestion of placing a bag of ice on top of the inverter itself to ensure cooling on a short trip. Just imagining how many bags of ice hypothetically it would take in your situation.

    I do know have the hood popped open to the release position (not closed, but still somewhat latched) , does allow some extra cooling for the inverter. I would secure this if done on the highway. Just a thought, not a suggestion. The best technical reason (in my understanding) not to try the cross country trip in the heat of summer, you can't easily check the voltage status of the car, and without a functioning inverter, the car eventually will quit from low 12 volt voltage.
     
  7. bisco

    bisco cookie crumbler

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    foot on brake, press power button once = ready.
     
  8. uart

    uart Senior Member

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    +1 on this.

    To check the inverter coolant pump is working do the following:

    1. Place the Prius in ready mode and (optionally) let it warm a minute or so until the engine cuts out.

    2. Pop the hood and remove the filler cap from the inverter coolant reservoir. (the smaller reservoir of pink fluid just above and to the side of the inverter).

    Look down the filler hole and you can fairly easily see the turbulence of the flowing fluid if the pump is working.
     
  9. 2009Prius

    2009Prius A Wimpy DIYer

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    Yes seems a classical inverter pump failure symptom.

    I may be paranoid but I would set the parking brake hard and place tire chucks (in addition to shifting to park) just in case the car goes crazy and decides to run me over while I am checking the reservoir.
     
  10. VisualMonster

    VisualMonster New Member

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    I checked the reservoir and it doesn't seem to be moving inside at all (I looked after the gas engine turned off but car was still in ready mode). I also noticed the tank is just below the low level which may be what caused the issue. I was just in pep boys and they don't carry this pink coolant, he said it is a dealership thing. Will we cause damage to the system by attempting this drive? Can I substitute anything to bring it back to the full mark? Mix in water until we get home and then have them flush it?
     
  11. andyprius

    andyprius Senior Member

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    The main clue to your post might be, that you were driving 75-80 up a 10 mile incline. If continuing your trip, make sure the coolant reservoir is full and gurgling! Otherwise, DO NOT DRIVE. If gurgling, slow down, drive at 55MPH, use AC but adjust AC temp to 72 to 78 after you get going. If 55 is all right you might raise the speed to 65MPH. But continue to monitor the cars operation. Powering off and on several times should clear codes, so will disconnecting the neg 12 volt ground lead. Both procedures are a form of rebooting. It appears that 75-80MPH + a steep 10 mile incline + full MAX AC setting is too much for poor little Prius, to treat her gently. Get that TSB as soon as possible! :cheer2: A perfect driving procedure is slow on the uphill and coast on the downhills, after all the purpose of buying a Prius was to save gasoline usage, right?
     
  12. VisualMonster

    VisualMonster New Member

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    Since it is not gurgling now, can I fill it up to the top using water since pep boys doesn't carry the pink stuff and toyota service isn't open for 2 more days. Once filled, could this start the gurgling in the reservoir since it doesn't seem to be doing anything now?
     
  13. uart

    uart Senior Member

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    I doubt that the level being "just below the low mark" would be enough to actually stop it flowing. I doubt that it will really help to increase the level at this stage, you need to get the inverter coolant pump replaced. (they have to drain and refill the coolant during this procedure anyway).
     
  14. uart

    uart Senior Member

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    If you do want to top it up and try and keep driving then I'd try to get a straight ethylene glycol product which shouldn't cause any problems, and it wont be in there for long anyway.

    If you do drive you want to go VERY easy on it with short trips, avoiding hills and try to avoid the hottest parts of the day. Personally I'm not sure it's worth the risk.
     
  15. andyprius

    andyprius Senior Member

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    BUY anything that Pep boys has that is roughly equivalent to the Pink coolant, it is only temporary PLUS most of the right coolant is still in the system. Stop at Toyota and get the TBS first chance. Either Sunday or Monday for sure. The job only takes an hour or two. Carry excess coolant with you to top up and consider an ice bag on top of inverter ( that is a good idea ) Monitor car closely, do not stress it. Cheers :cheer2:
     
  16. andyprius

    andyprius Senior Member

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    Just below the low mark, may be sufficient. To burn out the inverter!
     
  17. VisualMonster

    VisualMonster New Member

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    Will mixing in some water cause problems? Pretty much everything is closed now, so my option is to try water or stay in a hotel and try ethylene glycol tomorrow, or stay 2 days and have Toyota dealer check it out.

    btw, thanks for the replies everyone... very appreciated!
     
  18. uart

    uart Senior Member

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    Just get a basic ethylene glycol product from a gas station or something, it will be better than water.
     
  19. uart

    uart Senior Member

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    Don't take that out of context andy. The intake and outlet pipes are a good way below the "low" level on the reservoir. My comment was that being just below that level (but still well above the inlet and outlet pipes) is not likely the cause of the fluid not flowing. A failed inverter pump is the likely cause of that. My comment was specifically that simply topping up the fluid is unlikely to cause the coolant flow to "restart" at this stage.
     
  20. andyprius

    andyprius Senior Member

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    OK I will agree with that.