Speed Sensor Defeat Update

[rdverb]

I haven't installed any of these mods in my Prius, but I seem to recall some posts on the older chat site that talked about another downside to the speed sensor defeat switch related to the loss of dead reckoning in the Nav system ... the inability to estimate position when the GPS signal is lost.

Brosnan said the map features were unaffected, but you might want to check this out if that's important to you.

[brosnan]

Looks like there is a more accessible location for the speed sensor wire
to the MultiDisplay. And the wire to the Nav ECU is right next to it.
They are located behind the A/C panel just to the right of the radio.
It snaps out if you pull it toward the back of the vehicle.

The violet wire to the MultiDisplay (to pin 25 of M13) is at location
5E-12 of center connector #2. You could cut it here to gain
access to BlueTooth phone features while moving (at the expense
of MPG 5 minute interval bargraph and animated tire display).
A switch in series with this wire allows selecting between default
and moving-phone mode.

The violet wire to the Nav ECU (to pin 5 of N2) is at location
5E-11 of center connector #2. A switch in series with this
line gives you the GPS lockout defeat described elsewhere in this forum.
It's just an alternate location to the under-seat cut.

See photo for more detail.


Cut at your own risk! Anyone know how to coax these pins out of this
connector housing?

[8AA]

With DPDT or DPST switches you have no choice but to operate both switches at the same time. In the case of the two speed sensors, to defeat them you break (open) a connection. For this application then, you could use a DPST and break the connection for both at the same time.

If you use a DPDT, you can wire it up the same way, or have one circuit closed while the other one is open. This wouldn't make sense for this application, but who knows what other mods someone will come up with in the future.

[efusco]

Once again Brosnan, thanks and excellent work. That's much more accessible and seems like a great access point for one of those DPDT or DPST switches for single switch access to NAV and BT.

rdverb:
There are 2 seperate wires for NAV and BT. While dead reconning is, indeed, lost briefly while the switch is flipped it doesn't really matter. After about 45 sec. to 1 min. it seems to be restored automatically and the override is overridden itself. You have to close the circuit then re-open it. Bear in mind that if you're in the process of entering data into the Destination screen you can't see the map screen anyway. Once you're done you turn the switch back to close the circuit so the dead reconning inaccuracy is mute.

Likewise, when using BT phone, if you have a seperate switch, that won't affect NAV at all, but will have the side effects with the Consumption screen 5min bars and the stoppage of wheel turning on the Energy screen.

In any case, I find the added functionality would far outweigh any side effects and the beauty of a switch is that you can turn a feature off or on as needed with no permanant loss of function.

Ok Brosnan, you seem to be really up to my challenges...any way to install a switch that automatically enables BT and NAV when there's someone sitting in the passenger seat. I'm sure it's possible, though it may be a pretty tricky feat.

[Danny]

You could rig that to the weight senson on the passenger seat. Just figure out a way to tap into that wire.

[Ray Moore]

Why rig it to the seat? If Toyota had manufactured it this way, we'd be trying to figure out how to mod out this limitation. hehe

[brosnan]

efusco wrote:

Ok Brosnan, you seem to be really up to my challenges...any way to install a switch that automatically enables BT and NAV when there's someone sitting in the passenger seat. I'm sure it's possible, though it may be a pretty tricky feat.

Well the closest I can come right now is the circuit below. Due to the
way the passenger weight sensor is wired, it's tough to base the
lockout defeat based strictly on whether something (someone?) is
on the passenger seat. So the circuit below should defeat the
nav and phone lockouts if there is passenger seat weight AND
the passenger seat is NOT buckled. So it's really only useful for
single drivers using a backpack or similar weight on the passenger
seat to defeat the lockouts. I'll think about it some more, but since the
airbag deployment is based on these same signals, it's a little tricky.
By the way I have not tried this circuit, so I'm not positive it works.

Thanks to your challenges I've started thinking about what we'd
really like (besides Toyota just updating the firmware). Here's
what I think is possible with a circuit hidden in the dash:

1) When the driver presses the phone off hook button on the steering
wheel, defeat the Bluetooth phone speed lockout until the phone
on-hookup button is pressed.

2) When someone presses the DEST, INFO or MENU buttons on the
MultiDisplay frame, enter Nav Lockout Defeat mode. While in this
mode, open the Nav speed sensor line but periodically (every ~30sec)
reconnect it briefly to avoid the GPS-based secondary lockout.

3) Exit Nav speed lockout mode if either ~3 minutes goes by or
someone presses the MAP, CLIMATE, AUDIO or DISPLAY buttons
(including the MAP button on the steering wheel).

Does that leave out any important features? Any suggested changes?

A real stretch goal would be:
4) The first time after each vehicle start that either the MAP or DEST
buttons is pressed, simulate a touchpanel press near the "I Agree"
soft button.

[efusco]

I think that's a great set of goals. I think there are a couple different sets that people would want to consider:

1)Your set which is pure convenience and overrides all safety defaults whether there's a passenger or not.

2)A safety based set whereby when there is a passenger and the passenger has the seatbelt buckled then all speed sensor dependent lockouts are overridden automatically. This would assume that the passenger is entering all data.

I have no idea how to implement that circuit, but awesome job. You must have some pretty good background in all this as that BT override has eluded most others until now. Keep this kinda info coming!!

[Danny]

Your 516 Points are well earned. I bow before you and Evan

[brosnan]

Found another side effect of the Phone Speed Lockout Defeat mod:
When you fill up the gas tank and drive off, the consumption
screen will no longer automatically reset the trip distance.
So if you like this feature (or the 5 minute interval bargraphs
or animated spinning tires), a switch is desirable. Otherwise
just cutting or removing the wire to pin 25 of M13 will do the trick.