Speed Sensor Defeat Update

[blamy]

Originally Posted by efusco

No updates guys.

Wayne has told me he hasn't forgotten, but he's not very motivated to find a fix since he doesn't have any bluetooth services in his area.

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!

[zenMachine]

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.)

[John Milo]

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.

[zenMachine]

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...

[efusco]

Originally Posted by John Milo

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.

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.

[zenMachine]

Originally Posted by efusco

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.

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

... 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.

Oooh... I want, I want!!! Where to find info?

[Hybrid Hector]

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

Originally Posted by efusco

I finally got up the gumption to start pulling stuff apart and cutting wires and got the speed sensor defeat switch installed. Wasn't all that hard with the exception of working with a small short wire in a very tight space and figuring out how to get the center console out. Still, I completed the job in about 1-1/2 hours total time (my kids were napping and the first one got up just as I was picking up the tools to put them away.

So, once they were both up I loaded the car up for a test run to be sure everything worked.

I first tested the Bluetooth phone...b/c that's the main reason I wanted the switch in the first place since I have little need for the NAV itself. It didn't work. Flicked the switch multiple times, tried multiple screens and still I couldn't get the Phone Book or Direct dial to work. At that point I started sniffing for smoke and hoping that the brakes still worked since I was SURE I'd cut the wrong wire and now had a defeat for the entire Hybrid ECU or something!!!

The rational side of my head took over again and I switched to MAP---flicking the switch, sure enough, seemed to freeze the car icon on the map screen for about 30 sec. then it jumped to position when the GPS detected again. Seemed something was working. I switched then to the NAV page and sure enough, all direct entry functions were available just as if I was stopped!

So, I wrote to Wayne Brown, the first to do this mod. Turns out he doesn't have a Bluetooth phone and never tested that feature! It seems that a second switch or maybe another wire will need to be defeated to make the phone work. If I find that I think I'll just cut the wire permanently, can't think of any reason I'd ever need it to have those features disabled.

Anyway, I wanted to post this for the archives so that others considering doing the mod will know that it won't work for the Bluetooth. Wayne's promised to check the wiring diagrams and get back to me if he can figure out a defeat for the Bluetooth.

[efusco]

Originally Posted by Hybrid Hector

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

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.

[efusco]

Originally Posted by zenMachine

Oooh... I want, I want!!! Where to find info?

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.

[brosnan]

Originally Posted by efusco

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.

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