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

Traction Control Alarm Malfunction

Discussion in 'Gen 2 Prius Technical Discussion' started by meadowland, Jul 12, 2010.

  1. meadowland

    meadowland New Member

    Joined:
    Jul 12, 2010
    5
    0
    0
    Location:
    Minnesota
    Vehicle:
    2005 Prius
    Model:
    N/A
    My 2005 Prius (not sure what package # - it was the one with the most extras that year) has started sounding the vehicle stability control (VSC) alarm (yellow skidding car icon comes on and audible alarm sounds) for no apparent reason, on almost a daily basis.

    It usually happens during the first trip of the day, after I have traveled about one mile. On straight, level, dry road, when I briskly accellerate to about 55 mph, the alarm comes on. It stays on until I slow down to about 35 mph. If I'm on the freeway and continue at highway speeds, it will stay on constantly, for about 5 minutes, then it goes off.

    It happens usually 4 out of 5 weekday mornings in my 4 mile commute to the train station. It also happens at other times, usually early on in the trip. As a general rule after it has happened once, it doesn't happen again that day.

    I have kept an exact log of the occurrences, and had the car to the Toyota dealer now twice. Unfortunately [and very strangely] the Toyota technicians can't get the car to do it. They also say nothing is registered on the car's computer system.

    They have given up, and I have to pick the car up this afternoon. HELP! Has anyone else had this problem? Any advice? Thanks everyone. . .
     
  2. qbee42

    qbee42 My other car is a boat

    Joined:
    Mar 2, 2006
    18,058
    3,073
    7
    Location:
    Northern Michigan
    Vehicle:
    2006 Prius
    No codes would log if the car thinks there is a loss of traction. In that case it would be doing what it was designed to do. This suggests that there may be something weird going on with the wheel speed sensors that cause the ECU to think that one wheel is going slower than the other. I would look there first.

    Tom
     
    1 person likes this.
  3. meadowland

    meadowland New Member

    Joined:
    Jul 12, 2010
    5
    0
    0
    Location:
    Minnesota
    Vehicle:
    2005 Prius
    Model:
    N/A
    Tom, Thanks Very much! I just suggested what you said to the Toyota service guy (I think he may be a mgr. type, don't think he's the one actually working on the car). He says they have checked the front alignment and everything, he thinks including the wheel speed sensors, and everything appears to be OK. So he doesn't want to investigate further. He says the only way to diagnose the problem is for the alarm to malfunction while they have a computer hooked up to the car?!

    I'm going to go there this afternoon and drive the car myself with a technician onboard, hoping it will happen with the tech's computer on the car. My luck the alarm won't go off then, but will when I'm on my way home!#@#

    Thanks again, though, for your input. It sounds very logical - but I may have to take the car to a different Toyota dealer - at this point the guys I am dealing with are treating me like a nut case. . .Oh well, maybe they're right . . .lol.
     
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,198
    6,461
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    How much tread depth is on your tires, especially the front tires? I think your tires are just slipping, which is causing the skidding car icon to appear.
     
    1 person likes this.
  5. meadowland

    meadowland New Member

    Joined:
    Jul 12, 2010
    5
    0
    0
    Location:
    Minnesota
    Vehicle:
    2005 Prius
    Model:
    N/A
    Hi Patrick,

    They are practically brand new tires - were put on I think in March 2010. Come to think of it, they were put on not long before this alarm malfunction began . . sort of hard to know for sure, because my wife was driving the car then, and she didn't tell me about the alarm malfunction problem for awhile. Could it have something to do with the new tires??

    Rick
     
  6. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,198
    6,461
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    Hi Rick,

    I reread your edited OP, and it is very strange to consider that the light will stay on continuously for 5 min when at highway speeds; yet no error code is logged by the skid control ECU.

    - What brand/model of tires was installed?
    - What is the tire pressure?
    - Have you checked all four tires to make sure that they are all the correct size - 185/65R15?
    - do you want to know how to retrieve skid control ECU DTC yourself? Maybe a code can be retrieved if you look for codes immediately after the problem happens.
     
  7. meadowland

    meadowland New Member

    Joined:
    Jul 12, 2010
    5
    0
    0
    Location:
    Minnesota
    Vehicle:
    2005 Prius
    Model:
    N/A
    Patrick,

    I will get that information as soon as I pick up the car today. Don't recall the brand or size of tires, but they were installed by a repair shop in Cleveland [we just moved to Minnesota from there] whose owner is reputed to be an expert on Prius. It was not a Toyota dealer.

    I should have mentioned that I had a "minor" collision with a curb during a snowstorm a month or so earlier,and the shop replaced some of the control arms in front that got bent - will have to look at the receipt to know exactly what parts were replaced, but they were in the front suspension part of the car [I am mechanically uninclined, sorry for the vagueness]. While the car was there for those repairs, they told me my tires needed replaced due to wear, so I said go ahead.

    I do know that the alarm problem did not begin immediately after the accident, or even immediately after the front end repairs/tire replacement. It probably began about a month or so after work was done. Wish now we had kept closer track of it all.

    Yes, I would like to know how to retrieve the code after one of these alarm events. Thanks very much for all your help!

    Rick
     
  8. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,198
    6,461
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    Hi Rick,

    Make the car IG-OFF. Find the DLC3 connector (aka OBD-II connector) which is below the steering wheel column.

    Note that the connector has 16 terminals and has a trapezoid shape where one base is wider than the other. When looking at the connector so that the wider base is at the bottom, the numbering starts with #1 on the bottom right, and continues to #8 on the bottom left. #9 starts on the top right and continues to #16 on the top left. Put a jumper wire between terminals 4 and 13 and make the car READY.

    Look at the Brake Control (amber circle with ! within), ABS and VSC lights. If they produce a two-digit blink code, note what it is and post.

    If normal, the light will blink at 0.25 second intervals after a pause of 2 seconds.

    If a blink code will be logged, there will be a pause of 4 seconds, then the first digit of the blink code will come on as 0.5 second flashes followed by a 1.5 second pause. Then the second digit of the blink code will come on as 0.5 second flashes. If more than one blink code was logged, the second code will appear after a 2.5 second pause.
     
    2 people like this.
  9. meadowland

    meadowland New Member

    Joined:
    Jul 12, 2010
    5
    0
    0
    Location:
    Minnesota
    Vehicle:
    2005 Prius
    Model:
    N/A
    Patrick,

    Just got the info on the tires we had installed - turns out it was in January 2010 - 4 new 185/65R15 SE-200 tires. Then in March 2010 the same shop replaced the left and right front inner and outer tie rod ends (I thought all this stuff was done at the same time, but I guess not). I will check the tire pressure when I go to the Toyota dealer this afternoon - but I think that was one of the things they did - they said they also checked the front alignment and everything was ok. . .

    Rick
     
  10. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,198
    6,461
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    Hi Rick,

    When you have access to the car again, I suggest that you examine each of the four tires to make sure they are all the same size.
     
  11. richard schumacher

    richard schumacher shortbus driver

    Joined:
    Mar 27, 2004
    7,663
    1,037
    0
    Location:
    United States
    Vehicle:
    2004 Prius
    Model:
    N/A
  12. jeffscpu

    jeffscpu Junior Member

    Joined:
    Jul 29, 2010
    1
    0
    0
    Location:
    Buffalo, NY
    Vehicle:
    2005 Prius
    Model:
    N/A
    Hi Rick,

    I am having the same problem with my 05' Prius. Did you ever figure out what it was?

    Thanks!

    Jeff
     
  13. nikoli_v

    nikoli_v New Member

    Joined:
    May 30, 2015
    2
    0
    0
    Location:
    Dallas, TX
    Vehicle:
    2005 Prius
    Model:
    N/A
    Jeff, I do too! What did you do about the issue? Did you get it resolved?
     
  14. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,533
    48,842
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    mismatched tyres? speed sensors, hit a curb?
     
  15. nikoli_v

    nikoli_v New Member

    Joined:
    May 30, 2015
    2
    0
    0
    Location:
    Dallas, TX
    Vehicle:
    2005 Prius
    Model:
    N/A
    I hit a curb and had to replace the control arm and both struts. I didn't go to a licensed dealer because I didn't know I needed all the repairs, I just went in for any alignment because I saw my tire had a slight negative camber and I just thought it would be rectified with an alignment, though I did have a fear I would need the repairs, I didn't realize they were as urgent as they were.
     
  16. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,533
    48,842
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    sounds like you'll have to get a thorough inspection/diagnosis. dealer or qualified tech.
     
  17. Thomas74

    Thomas74 New Member

    Joined:
    Jan 22, 2017
    1
    0
    0
    Location:
    Hungary
    Vehicle:
    2007 Prius
    Model:
    N/A

    I have the same problem and noone knows the solution
    Hi Patrick,
    I have the same problem and techicans cannot solve yet. Skidding icon flashes 3 - 6- 4 -1 times. can you help what it means?
    Thanks!

    Thomas
     
  18. P4ulK

    P4ulK New Member

    Joined:
    Jun 6, 2023
    1
    0
    0
    Location:
    CA
    Vehicle:
    2008 Prius
    Model:
    N/A
    I found this thread trying to find if anyone else had solved this problem, but now that I think I have solved it, let me share.

    I had a car with the same conditions described above: flashing traction light and audible warning on acceleration up to 30-50mph. Wouldn’t turn off until speed dropped below 25mph. No codes, plugged in my scanner and all 4 wheel speeds read the same when going straight, even when the alarm was beeping. I was (and honestly still am) puzzled as to why the car was sounding the traction alarm when it was clear from the inputs it shouldn’t be sensing one wheel moving faster than the other.
    This car came in needing suspension work with the F/R wheel way out of alignment. The problem began shortly after repair. None of the work I did affected the speed sensor or any other traction control element.
    Out of curiosity I cleared the traction control computer memory and reinitialized the yaw rate sensor and other steering/brake/traction control sensors.
    Now the light doesn’t come on! Long term testing will show if that fixed it or not but the only thing I can figure is driving with the alignment so far off gradually recalibrated the yaw sensor to accommodate and so fixing the issue made the car miscalculate its position? I do not know, but it seems to have worked!