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

Brake/!/ABS/VSC continuing problem...

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Rapid Dog, Jan 24, 2014.

Page 1 of 4
  1. Rapid Dog

    Rapid Dog Member

    Joined:
    May 9, 2011
    101
    4
    0
    Location:
    SoCal
    Vehicle:
    2010 Prius
    Model:
    II
    2005 Prius 100,000 miles, 60K I put on it without a hitch.
    Bought used.

    Had these lights come on before the holidays and took it in to the dealer.
    Here's the rundown:
    First visit:
    'The code was a hydraulic code, but we couldn't find anything. Cleaned your rear brakes, you need a fan belt"

    Lights came on again a few weeks later.
    Second visit:
    "We bleed the brakes, found a bubble."
    Well why didn't you do that the first time?
    "Um, well only charge you $75..."

    Third visit:
    So one day at work I went out to the car and noticed I left my dome light on all day.
    The car did stuff I've never experienced. All the warning lights came up, including a message telling me to park on level ground (I was) and operate the parking brake (I did). Several attempts to get it to actually go into gear later, I succeeded and drove straight to the dealer.

    Caveat: This car had either been stolen or the 12v battery stolen at one time. The positive (aluminum) cable had been cut off and then repaired. In 3 years and 60K there hasn't been a problem...

    I told the service guy to check that cable end,
    "It's throwing a different code, this time, something with the transmission"
    then..
    "You need to replace that entire $850 + $550 labor wiring harness before we can find out what's really wrong".
    Did you test the 12v battery?
    "Yes it's 7 years old, needs to be replaced also"
    Tell you what, let's replace the battery first and see what happens...

    So $385 later it's all good. I checked the repaired cable connection and the repair was loose.
    So I got an $8 splice connector specifically designed for aluminum cables and repaired it.
    All good. It's been a week or so without a problem.
    Then, yesterday I go out at lunch and realize I left the dome light on again...DOH!
    Brake/!/ABS/VSC are on again.

    This time I go home, put an ohmeter on the new battery, it reads 12.6v-ish.
    Disconnect the positive cables and remove the connector box and charge the battery for a couple hours.
    Back up to 13.5+v.
    Reconnect everything but the lights are still on.

    Long-winded story I know.
    I have to agree that somehow there's a draw on the 12V battery. But not sure it wasn't just my absent minded goof of leaving the dome light on and then it kicking the code/warning lights on.

    I want to know how to get the lights off again without going back to the dealer so that I can see if it had to do with the dome being left on (again).

    I'm all ears friends...
     
    #1 Rapid Dog, Jan 24, 2014
  2. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,917
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    Your problem was the low 12 volt battery the first and second time. The warning about parking on level ground is typical of this. You say you have charged your battery to 12.5 volts, while this will work it is by no means fully charged. The usual reason for this is that the charger you are using is for normal flooded lead acid batteries. The Prius battery is an AGM battery and should charge to at leased 12.8 volts and as high as 13.1 volts. Some ordinary battery chargers will not do this, and in the long term could damage the battery by under charging it.
    It is unlikely the warning lights are caused by the battery and you need to ask the dealer for the codes and post them here for diagnosis.
    Disconnecting the 12 volt battery for a few minutes will normally turn off the lights and remove the codes.

    John (Britprius)
     
    #2 Britprius, Jan 24, 2014
    usnavystgc likes this.
  3. Rapid Dog

    Rapid Dog Member

    Joined:
    May 9, 2011
    101
    4
    0
    Location:
    SoCal
    Vehicle:
    2010 Prius
    Model:
    II
    Thanks for that.
    As a not, I used a standard Sears charger and the ohmeter test was then at 13.5+.
    I do have an AGM motorcycle charger that I could use as well in the future.
    I'll get the codes and post them today ASAP.
     
    #3 Rapid Dog, Jan 24, 2014
  4. Rapid Dog

    Rapid Dog Member

    Joined:
    May 9, 2011
    101
    4
    0
    Location:
    SoCal
    Vehicle:
    2010 Prius
    Model:
    II
    O.K., here are the codes from last dealer isit:
    C2318 - Low Voltage Error
    P3102-581 - Transmission Control ECU
    C2300 - Actuator Malfunction

    Not necessarily in that order, wife reading to me over the phone ;) ...
     
    #4 Rapid Dog, Jan 24, 2014
  5. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,917
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    The reading of 13.5 volts is probably being taken immediately the battery comes off charge. This is a false reading. the battery should stand over night or have a small load put on it before taking the readings.
    I should have addressed your comments about the battery cable, as long as the joint (repair) is sound and not corroded there should be no problems with it.

    John (Britprius)
     
    #5 Britprius, Jan 24, 2014
    usnavystgc likes this.
  6. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

    Joined:
    Jul 29, 2011
    3,159
    989
    0
    Location:
    Tucson, AZ
    Vehicle:
    2005 Prius
    Model:
    Four
    Yeah those codes seem indicative of a low 12v power source. C2318, tells you low power, then the ECU and Actuator don't have reliable power. Get the car back, disconnect the 12V, charge it to 100% charge, reinstall, turn on the lights and check voltage. If all is good try to start car. Post the results here.
     
    #6 usnavystgc, Jan 24, 2014
    Britprius likes this.
  7. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,917
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    Usnavystgc beat me to it, but what he said.
    If you wish to save money by not having to go to the dealer, I strongly suggest you invest in a Mini VCI with Techstream (about $30 on Ebay) + your laptop. This will allow you to read the codes clear them, and do virtually anything the dealer can do in the way of tests and service jobs including bleeding brakes.
    If you disconnect the battery it is normal to have to try restarting (make ready) the car twice before success.

    John (Britprius)
     
    #7 Britprius, Jan 24, 2014
    usnavystgc likes this.
  8. Rapid Dog

    Rapid Dog Member

    Joined:
    May 9, 2011
    101
    4
    0
    Location:
    SoCal
    Vehicle:
    2010 Prius
    Model:
    II
    O.K., will do.
    It had no problem starting and driving this morning. Just the lights are on.
    By test driving a bit last night, by 'feel', I'd say the ABS is not working but the traction control is.
    But first things first. I'll do the charge/ test again tonight and post results.

    The cable repair is fresh with a new aluminum splice connector and showed no corrosion at all. It was just loose at the splice before.
     
    #8 Rapid Dog, Jan 24, 2014
  9. Rapid Dog

    Rapid Dog Member

    Joined:
    May 9, 2011
    101
    4
    0
    Location:
    SoCal
    Vehicle:
    2010 Prius
    Model:
    II
    #9 Rapid Dog, Jan 24, 2014
  10. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,917
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    One other thing while your in there, check the negative cable for tightness where it is bolted to the rear bodywork. This connection is prone to being loose or corroded. Many and various faults can be reported by the Prius ECU's if the 12 volt battery is low or the 12 volt supply is unstable due to poor connections. The most prolific of these is the "parking is abnormal park on level ground" warning. This is virtually always a 12 volt problem.

    John. (Britprius)
     
    #10 Britprius, Jan 24, 2014
  11. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,200
    6,482
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    And to clear DTC logged by the skid control ECU, there is a procedure where you jump pins 4 and 13 of the OBD-II connector. It's not sufficient just to disconnect 12V power. Do a search for that, if interested.
     
    #11 Patrick Wong, Jan 24, 2014
  12. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,917
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    Yes, and as you can see the cost is far less than going to the dealer for diagnosis. There have been odd reports of faulty units and the possibility of a virus on the disc, but I have not found any problems myself or with many friends that have them. It runs on Vista or XP but can be made to run on Windows 7 or 8/8.1.

    John (Britprius)
     
    #12 Britprius, Jan 24, 2014
  13. Rapid Dog

    Rapid Dog Member

    Joined:
    May 9, 2011
    101
    4
    0
    Location:
    SoCal
    Vehicle:
    2010 Prius
    Model:
    II
    ...problem is though, I don't own a laptop. Had this problem on my motos as well.
    I have a work laptop I could use but it's blocked from installing other software so it's useless there.
     
    #13 Rapid Dog, Jan 24, 2014
  14. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,917
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    Even with buying an old secondhand laptop (does not need to be fast or have lots of memory, I run on a 15 year old IBM) will still be cheaper than the dealer, and will come in for future use. It will work on any Toyota and will also diagnose emissions (engine) codes on any vehicle with the standard ODD2 connector. You can of course use a desk top but that becomes cumbersome.

    John (Britprius)
     
    #14 Britprius, Jan 24, 2014
  15. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,917
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    I would suggest just to be safe, you drive on a clear piece of road at 30 to 40 mph, put the car into neutral, and brake. This will prove you are not relying on regen braking, and that the normal hydraulic brakes are operating. Safety first!!

    John (Britprius)
     
    #15 Britprius, Jan 24, 2014
  16. Rapid Dog

    Rapid Dog Member

    Joined:
    May 9, 2011
    101
    4
    0
    Location:
    SoCal
    Vehicle:
    2010 Prius
    Model:
    II
    O.K. at my lunch hour I did the self diagnostic procedure here:
    Weird stuff happening? MPGs dropping? Test The Battery | PriusChat

    12V battery seems to check out O.K....
    Vehicle Signal Check - the battery voltage is shown and should be about 12.4 to 12.8 Volts (normal for an unloaded battery) - Check! At 12.4V.
    Press Power button and release to put a current load on the battery - the voltage should stay above 12.0V - Check! At 12.1V.
    ​
    If that's good, then what next? (lights are still on of course).
    I'll try the ground disconnect tonight.
     
    #16 Rapid Dog, Jan 24, 2014
  17. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,917
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    I would clear the codes "as you already have a note of them". Test the brakes as in my post 15 for safety. Then see if the lights reappear. If they do the codes can then be checked again to establish which have gone away and what remains.
    I know this may seem long winded, but the 12 volt battery problems have to be eliminated first as we have already said this can and does lead to all sorts of spurious non existent fault codes as the ECU's try to operate monitoring system voltages that are lower than expected. Eg, electric hydraulic pump runs slowly giving slow pressure buildup, the ECU could interpretate this as low pressure, a leak in the pressure system, or a faulty pump.

    John (Britprius)
     
    #17 Britprius, Jan 24, 2014
  18. Rapid Dog

    Rapid Dog Member

    Joined:
    May 9, 2011
    101
    4
    0
    Location:
    SoCal
    Vehicle:
    2010 Prius
    Model:
    II
    By 'clear the codes' you mean disconnect the negative ground for 10 minutes?
    This is what's confusing...I had the positive pole completely disconnected last night while charging the battery.
    But the lights did no go away.

    Maybe there's something I missed.
     
    #18 Rapid Dog, Jan 24, 2014
  19. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,917
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    See post 11 from Patrick Wong re clearing brake codes.

    John (Britprius)
     
    #19 Britprius, Jan 24, 2014
  20. Rapid Dog

    Rapid Dog Member

    Joined:
    May 9, 2011
    101
    4
    0
    Location:
    SoCal
    Vehicle:
    2010 Prius
    Model:
    II
    O.K., did the " jump pins 4 and 13 of the OBD-II connector on Friday when I got home. All good. All lights were off.
    This morning I stopped for a train crossing and put it in Park for 5 or 6 minutes waiting.
    About 3 blocks away the same lights are back on...

    I did the voltage checjk when I got to work using the info/maintenance screen.
    12.7 volts, then with the lights turned down to 11.6-11.7 volts.
    That's with the radio and A/C turned off.

    Keep in mind this is a brand new $200 battery from the dealer, about a week old.
    So I guess the dealer was right about one thing, something is drawing down the 12V battery.
    But what, I don't have a clue...I'm not about to replace that harness for $1400 to find out either!
    I'll clear the lights and trade it in before that happens.
    100,750 miles on this car.
    ​
     
    #20 Rapid Dog, Jan 28, 2014
(You must log in or sign up to post here.)
Page 1 of 4