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Speed Sensor Defeat Update

Discussion in 'Gen 2 Prius Audio and Electronics' started by efusco, Jan 27, 2004.

  1. efusco

    efusco Moderator Emeritus
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    You can do that on the early models too...and occasionally I do. But if the phone is difficult to access (in a pocket or clipped to your belt or whatever) it's easier to hit a switch and tap the number on the BT list. Also, I find it a lot harder to pick out the number on the phone while driving...I think it's safer to use the MFD.
    Finally, there's always a delay with the connection and some 'dead time'. IOW, if I dial a number via the cell phone it will ring through the cell phone until the person answers the phone...then there's about 2-3 seconds while the call transfers over to the BT/Prius from the cell and the person at the other end of the call hears nothing. I always end up starting the call with an apology about the dead time and explaining why it occured. It's not a huge deal, but it's also nice to be able to directly enter numbers via the MFD and have none of those issues to deal with.
     
  2. ntog

    ntog New Member

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    This thread can be difficult to understand because some posts are about the Bluetooth/telephone speed sensor defeat and some are about the NAV speed sensor defeat. Each is VERY different -- different connection to connect and different impact to operation. I did not do the telephone modification but the posts seem to suggest that the connection can be cut without significant impact to other functions (except the display of mileage bars and wheels turning) HOWEVER I did the NAV modification on my 2008 and it requires the installation of a switch because the NAV will not work without the connection. There appears to be plenty of options for installing a switch -- I put a push/toggle switch on the left wall inside the upper glove box. When we need to do anything with NAV while moving -- we just pop the glove box, press the switch, make the entries/selections and then press the switch again. Works wonderfully...is out of sight and was easy to install.
     
  3. Tom6850

    Tom6850 Retired

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    I certainly agree with that. It really would be nice to have the cars system automatically connect to the phones directory the way my Garmin Nuvi does without transfering the phone book to the cars system at all. I do admire those of you who are willing to modify the cars system. At one time I would have jumped right in and tried it also, but now as I am getting older, I am not quite as brave as I used to be.
     
  4. FlyFamily1

    FlyFamily1 New Member

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    Thanks for the reply! Based on your feedback, I installed two switches for the overrides. This works very very well. I think this is much safer than fiddling with the phone, and much better for nav changes.

    One thing I noticed on my BT override is that the instantaneous mpg readout still works. The only functionality loss I see is the bars on the Consumption screen.

    This is good to know. I tried a few things on my drive home last night, and didn't run into a situation where the secondary lockout kicked in. I don't remember the longest amount of time that I left the override on, but I was certainly able to do the things I needed to do.
     
  5. sweetguy

    sweetguy Junior Member

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    I assume you all know that the BT still works while moving if you use the voice commands? On my 2008, I can call any number that I can remember by using the voice system while the car is moving. It would be better to not have functions disabled but voice is a work around.

    Also, for any of you that would like to be able to find most numbers for free, call 800 FREE 411 from any landline or cell phone. You get a 10-second ad and then free directory assistance.
     
  6. FlyFamily1

    FlyFamily1 New Member

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    That is the issue. You have to know the number. I agree that the voice dial works very well. Also, using voice for entering an address is best when driving. However, having access to my phone book on the big screen for numbers I don't know is the safest/quickest route, and being able to reorder an itinerary or put in a POI by name is fantastic.
     
  7. pfmanny

    pfmanny New Member

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    Thanks for posting this good info although im having trouble figuring out which wires you are talking about could you post some pictures? :bowl:
     
  8. darelldd

    darelldd Prius is our Gas Guzzler

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    Does my page help?
    Prius Speed Wire
     
  9. zenMachine

    zenMachine Just another Onionhead

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    I'd like to know the difference(s) between the BT mod provided here (cutting the speed sensor wire) and the one sold by Coastal.

    Thanks.
     
  10. alanh

    alanh Active Member

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    Since some people asked ... a user named Brosnan posted some circuit diagrams back in 2004, but subsequent upgrades of Priuschat.com caused them to disappear.

    You can see them on the Internet Archive's Wayback machine at PriusChat.com :: View topic - Speed Sensor Defeat Update

    All of them appear to be there except for the automatic dual-defeat schematic.

    The slow-motion nav defeat looks interesting.
     
  11. blamy

    blamy Member

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    Bluetooth is in the phone you buy and the device you use. There is no "Bluetooth service" from any of the Carriers. If you buy a Bluetooth Phone and a Bluetooth car kit you can talk hands free using Bluetooth. My wife uses the Toyota Bluetook car kit that comes from the factory and when driving the functions are disabled. I use a Motorola B/T car kit and don't have the problem or the fancy screen to use either:(. Any way he can have B/T if he has the right phone and a car kit to match. Hope Wayne gets hot as we generally use the wifes car for long trips and it is a pain!
     
  12. zenMachine

    zenMachine Just another Onionhead

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    Thanks to all who've gone before, I've finally been able to install the BT defeat switch with relative ease.

    I used this SPST switch from RadioShack. No need for soldering. Just used two flat F-connectors to connect my zip cord to the two poles on the switch. At the other end I used bullet connectors for the cut wire to make it easier to reconnect it later if needed.

    I installed the switch between the SKS and Tire Sensor buttons to avoid having to drill any holes. The switch is a little wider than the precut hole, but nothing a sharp hobby knife couldn't rectify.

    I also discovered that the panel removal tool is excellent for prying the A/C panel out. And it's helpful to open both upper and lower glovebox to give yourself more room to work.

    Since my car doesn't have Nav, this is all I need. For a car with Nav, I'd imagine a DPST switch in that same location would do the trick very nicely.

    I can't believe I hadn't done this mod earlier. My wife and I carpool and we take turn driving. This will make our driving experience a lot better (and safer too.)
     
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  13. John Milo

    John Milo New Member

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    I'm not quite sure what the point of the switch is? I just cut the speed wire ( left enough wire on either side to splice togehter when ready to sell) and left it like that. This way the phone, MP3 detail and FM message info is always on. Why is a switch needed to see 5' consumption bars and the wheels turn? Also, the install is much easier and faster - just pop off the center speaker grill and cut the wire. I don't mean this to sound like it's dumb to add a switch, I'm just not sure what it's for.
     
  14. zenMachine

    zenMachine Just another Onionhead

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    I suppose if you don't have Nav then a switch just for the BT is not as necessary.

    For me, I prefer the ability to keep the original functionalities intact. If I need to take the car to the dealership for service, for instance, I don't want them to see that something is "wrong" with the car...
     
  15. efusco

    efusco Moderator Emeritus
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    Well...which switch...
    1) NAV speed sensor--clearly necessary as the NAV computer will, after about 30 seconds, detect that you are moving from the GPS signal and will re-gray out the NAV buttons. You have to use the switch to 'reset' to speed sensor sensing and then disable to 'buy' another 30 seconds.

    2) BT speed sensor--I like seeing my consumption bars and the wheels turn...just feels normal. But other than that there's no reason you have to put in a switch. In fact I don't have one since I have a circuit that allows me to use the steering wheel controls to disable and enable the speed sensor.
     
  16. zenMachine

    zenMachine Just another Onionhead

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    I think his car is 08 pkg 3, thus no Nav.

    Oooh... I want, I want!!! Where to find info?
     
  17. Hybrid Hector

    Hybrid Hector New Member

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    I also tried the speed sensor "cut wire" approach" for NAV freedom to program while driving. It works, but there are some draw backs. While you are progamming the NAV, the map stops updating your position as you drive along UNTIL you flick the switch back to recreate the factory mode. The longer you program you NAV while driving, the farther off your map will be from your actual location. One time, we had diven so far that the map was "lost" and was not able to figure out our current GPS location until we shut the car off for 30 minutes. If anybody has another explanation for our observations, please post ! THANKS

     
  18. efusco

    efusco Moderator Emeritus
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    While you do lose the 'dead reckoning' during the time the speed sensor wire is disabled it shouldn't be permanant...indeed once things go gray again that means that the GPS is now doing all the tracking and should have you located back on the map accurately...but the GPS only updates the position every 20 seconds or so...which is why the dead reckoning is so useful as it can approximate your position b/w GPS 'pings'.

    I can't see any reason the car would need to be off for 30 min. I've used both the speed sensor wire cut method and the "Easter Egg" method available for those of us with an '06 or earlier and at no time have I gotten more than a few hundred yards off my course before the GPS 'found' me and got me back on the map accurately.
     
  19. efusco

    efusco Moderator Emeritus
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    I used to have a copy of the circuit design, I think there were only 2 or 3 of these ever built...one of which I have. It's a very very sweet way to use the BT (and nav, but I already had my Nav work around so just opted for the BT circuit). But it was labor intensive to build.
    Not sure why Coastal hasn't done something like this by now.
     
  20. brosnan

    brosnan Member

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    Here's the schematic of the BT speed sensor auto defeat in case anyone wants to build one: http://www.wb5mrn.com/prius/bt_only_schematic.jpg
     
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