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

Cruise control only works intermittently

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by terramir, Feb 6, 2016.

  1. terramir

    terramir Member

    Joined:
    Aug 3, 2015
    305
    47
    2
    Location:
    Los Angeles
    Vehicle:
    2004 Prius
    Model:
    II
    First it wouldn't turn on, at times now it at times won't work even though the light is on, on the dash. At other times it works as expected. I dun think it's the 12V battery, because when only the center console is on in diagnostics the battery reads 12.2-12.4 and 14.5 + when the engine is on.
    Help
    A terramir
     
  2. andrewclaus

    andrewclaus Active Member

    Joined:
    Sep 15, 2009
    993
    323
    0
    Location:
    Golden, CO
    Vehicle:
    2007 Prius
    It sounds like you've eliminated the clockspring, the normal culprit, since the dash light is on.

    I've seen the switches available on eBay. If there's a market for those, there may be a reason and I'd suspect that first. They may be easy enough to troubleshoot with a good ohmmeter and wiring diagram--only three wires and some internal resistors as I recall. You need to pull the airbag to get at it--use caution and get good instruction if needed.

    You may be able to check that at the ECU, but I suspect taking the wheel apart might be easier. But checking at the ECU will also check the wiring harness and clockspring, the next logical step.

    If that's not it, you may need to diagnose the ECU. Do you have a Mini VCI? If not, it might be worth it for this.
     
  3. terramir

    terramir Member

    Joined:
    Aug 3, 2015
    305
    47
    2
    Location:
    Los Angeles
    Vehicle:
    2004 Prius
    Model:
    II
    Hmm mini Vci for cruise control error is, lost communication with brake control module, u0129
    Where would that control module be? And where is the ecu so I can trace the wires either way
    terramir
     
  4. Dion Kraft

    Dion Kraft Member

    Joined:
    Nov 16, 2015
    272
    79
    1
    Location:
    Washington, UT
    Vehicle:
    2004 Prius
    Model:
    Two
    Some easy testing. Turn the steering wheel ( in different positions) to see if the cruise ON light will go on. If it does it indicated the ribbon cable is bad.
     
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,198
    6,461
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    If you want to DIY, it is time for you to obtain the factory repair manual at techinfo.toyota.com so that you can follow the voltage measurement and the comm line connections between the engine ECU, hybrid vehicle ECU, skid control ECU, and traction battery ECU. The first two are behind the glove compartment. The third is located near the steering column while the last ECU is within the traction battery case.
     
  6. Stevewoods

    Stevewoods Senior Member

    Joined:
    Jun 10, 2014
    647
    983
    0
    Location:
    Seattle, WA
    Vehicle:
    2008 Prius
    Model:
    II
    My experience with Cruise Control relates to "other than Prius," but basic principles should be somewhat the same.

    First, most cars develop cruise control problems as they age -- duh. Most of us figure we can live without cruise control and don't bother to fix it.

    But...In terms of your cruise control, the first thing I always checked was the fuse....yours is an intermittent problem and the fuse is probably not involved....but I would still check it. That would be the cheapest thing to fix.

    I don't know the details on the Prius system, but if the fuse is fine, then the switch at the brake pedal could be worn out, or out of adjustment. A bad switch or a sticky switch could cause troubles.

    Personally, I would not bother...
     
  7. Dion Kraft

    Dion Kraft Member

    Joined:
    Nov 16, 2015
    272
    79
    1
    Location:
    Washington, UT
    Vehicle:
    2004 Prius
    Model:
    Two
    The cruise control works via using ohm values to send to a decoder/multipexer/module to tell it what switches are pressed.
    The states are:

    on/off
    Resume/set
    Cancel

    These values are transmitted via two wires. When these values are sent to the ECU the ECU does the command which the value dictates.
    So if you have a bad ribbon cable and the command value is not transmitted. Also the value is not recognized as its transmitted but the value does not fall in the values of the program data list. Either no data was transmitted or value not within the parameters.as well.
    Repairs or diagnosis should always start with the mickey mouse parts first and most certainly the most physical to wear. Of course I will add in cheapest if this is to be a shotgun repair lol! Thats why its prudent to checkout the basics first before ripping into the ECU or any other wiring.
     
  8. terramir

    terramir Member

    Joined:
    Aug 3, 2015
    305
    47
    2
    Location:
    Los Angeles
    Vehicle:
    2004 Prius
    Model:
    II
    Thank you every one for your input, Dion Kraft you hit the nail on the head I rotated the steering wheel and sure enough in some positions it would turn on in some it wouldn't. Now how do I go about replacing that cable, because honestly I really like cruise control for various reasons one =) of em being resting my feet as much as possible, #2 I just dun pulse and glide that well so I'm better off with the cruise control
    Please where can I get that part and how would I put that in?
     
  9. andrewclaus

    andrewclaus Active Member

    Joined:
    Sep 15, 2009
    993
    323
    0
    Location:
    Golden, CO
    Vehicle:
    2007 Prius
    There are other threads here on the clockspring, also called spiral cable, replacement. And some vids on Youtube. Pay heed to a recent one about being wary of the cheap knock-offs available for $30 on eBay, etc. Use your VIN to get the right part number--various configurations are available for the same model year. Pay attention to transferring the steering angle sensor if you have VSC. Don't do it if you're not comfortable working safely with the airbag. Otherwise it's a straight-forward DIY repair.
     
  10. Dion Kraft

    Dion Kraft Member

    Joined:
    Nov 16, 2015
    272
    79
    1
    Location:
    Washington, UT
    Vehicle:
    2004 Prius
    Model:
    Two
    Okay well I usually get my parts on eBAY and you will have to decide on price point and/or go genueine (OEM) or after market.
    I went the cheap way and bought but not installed one yet. Initially my cruise ctrl was flaky so I bought a used one and put it in box under breakfast table as we type/speak here. Then I got this brainy storm to get a leather wrapped steering wheel...done,..now after market ribbon cable...LOL! I see it's time to slam dunk them in..For install check out YouTube for videos. Even If I am a seasoned mechanic 39 years experience its always good to go thru someone elses run thru so as not to screw up! Oh yeah..even a pro messes up if this is the first time! sometimes. But check those videos out and as well as search for website still pics on this subject. It is not difficult but as always never get too cocky. Some fear is always good to keep you sharp. When I joined here there was a post here on someone who did install a ribbon cable and they had codes now which he didn't when he started. Ended up he did not pay attention and forgot to plug in one cable!
    ALWAYS DC (double check) your work as sometimes your own repair can result in more problems than it should have.

    In closing the only thing to remember is that once you release the airbag and remove make sure the steering wheel is centered at all times.
    Make sure the ribbon cable install centered orientation is pointing at itself when installing. As I said just cruise thru the videos..the more you see them the plan becomes a blue print in your mind.
     
  11. terramir

    terramir Member

    Joined:
    Aug 3, 2015
    305
    47
    2
    Location:
    Los Angeles
    Vehicle:
    2004 Prius
    Model:
    II
    I have been looking for videos looks like nobody really made one with a prius, if I pull the negative on the 12v battery, I should be able to work with the airbag safely. But seems like I can't find videos for prius specific instructions for steering wheel airbag or the clock spring on youtube. I'll have to check the forums if I can find good instructions. I am fairly comfortable fixing anything.
    terramir
     
  12. Dion Kraft

    Dion Kraft Member

    Joined:
    Nov 16, 2015
    272
    79
    1
    Location:
    Washington, UT
    Vehicle:
    2004 Prius
    Model:
    Two
    I thought there was one on the Prius clock spring but looking..NOPE MY BAD!

    Well then this is the procedure. UNBOLT the negative terminal of the 12 Volt battery so your safe. Wait a couple of minutes to be sure. Look for procedure to remove airbag on Youtube or search under the PriusChat Search box. Straighten steering wheel so its at 12 o'clock.
    You can unbolt the steering retainer nut. unattach allt he wiring to the cable. Then supposedly you can pull the steering wheel off...normally you need a puller but this is a first for me insofar as pulling it off bare hands but there it is. Then you see the clockspring cable device.
    Let me see If I can get some pics..

    This thread has some info of use:

    New Prius Clockspring Part# 84306-0E010 | PriusChat
     
  13. terramir

    terramir Member

    Joined:
    Aug 3, 2015
    305
    47
    2
    Location:
    Los Angeles
    Vehicle:
    2004 Prius
    Model:
    II
    a little side note, I see you got two prius'es with different trim packages, I have been wondering what package I got 04 prius this is what I can tell I have (should have).
    radio, tape,6 cd changer jbl audio
    fog lights (missing with grill but wires and controls are there)
    side curtain airbags in seats and panels by windshield.
    vsc pretty sure since that is one of the lights that turns on when I start the thing.
    navigation
    bluetooth
    well ac and heat i guess is standard.
    the alumiunum rims with the ugly plastic circles ( I lost one) eventually I'll tear the other 3 off and use black rubber spray on those rims
    any clue what my trim is
    terramir
    ps: those things are now 15 bucks on ebay, got the part number from the dealer 84306-48030 gave them my vin.
     
  14. Dion Kraft

    Dion Kraft Member

    Joined:
    Nov 16, 2015
    272
    79
    1
    Location:
    Washington, UT
    Vehicle:
    2004 Prius
    Model:
    Two
    Yeah I drive the 04 while wifey drives the 09. Mines looks to be the Package 3 but Iwith CD and seperate Toy CD in the bottom bay below radio head. Check this thread and PDF dload of packages: About three msgs down:
    2009 Option Packages | PriusChat
    Also I scored a new trim ring on ebay for $20 last week. He had four listed genuine and NEW! in the orig bag!
     
  15. red04prius

    red04prius Junior Member

    Joined:
    Jan 16, 2016
    17
    1
    0
    Location:
    Atlanta, GA
    Vehicle:
    2004 Prius
    Model:
    N/A
    Let me bump this thread for future readers.

    For more than a year, I have been trying to diagnose why my cruise control has not been working. I went to the local dealer and spent $150 on diagnosis and waited for hours on end. They told me the cruise control switch needs to be replaced. I came back home and I put in a brand new OEM cruise control switch. But it still didn't work.

    I took it back to the dealer and they worked on it a few more hours. Or at least they pretended to. I am almost certain they did not work on the car since the battery was never disconnected when I got back into the car (the trip meters, clock, seat belt and reverse beeps all get reset when the battery is disconnected but none of them did). At the end of the day, they said they need to open up the entire dashboard and get to the wires and will need at least 2 more hours and I will have to pay for that. I walked away.

    After reading what Dion Kraft mentioned about trying to switch on the cruise control at different positions of the steering wheel, I was shocked to find that my old supposedly non-working cruise control switch is indeed working! By the way, I had just taken out the new switch to return to get my money back given that the cruise control switch was never the problem to begin with. So I have my original switch back in my car.

    For those of you in the future diagnosing this in the future, please try this first -- rotate the steering wheel at 5 degree steps and keep pressing the cruise control switch. It may indeed work. And if it does, then the clockspring is likely the issue.
     
  16. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,463
    8,377
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    That was a lot of reading to get to the result......clockspring is the issue
     
  17. red04prius

    red04prius Junior Member

    Joined:
    Jan 16, 2016
    17
    1
    0
    Location:
    Atlanta, GA
    Vehicle:
    2004 Prius
    Model:
    N/A
    The internet, smartphones, social media and multi-tasking has dramatically reduced our patience to read, unfortunately.