Anyone Have Access To Ride A Ferry?

[RhoXS]

I want to test a theory associated with being permanently able to override the Nav system lockout. To do this I need the vehicle stationary with respect to the wheels not turning but have it actually change location enough to see the change on the map display. A ferry seems like the perfect way to do this but there is no ferry I have access to.

This is why I want to know:

It is known that the nav system will stop updating the map position if the vehicle speed sensor signal is disconnected, even though it is still a fully functional stand alone GPS that should not require any external input except for power. It appears obvious, at least to me, this behavior is an intentional deterrent to prevent disconnecting the vehicle speed sensor signal so one can regain full control of the nav system.

I am trying to determine if the nav system behaves this way because it is programmed to not update unless it sees some small but finite speed from the vehicle speed sensor (no practicle work around) or, if I am lucky, it looks for a small positive DC voltage that may likely be present at zero speed on the input from the speed sensor (an easy work around).

A little research located an Electrical Wiring Diagram with an ultra simplified schematic of the "C17 Combination Meter" (where the speed signal comes from). It clearly shows how the speed signal that the Nav system uses is derived. The signal going to Nav system is pulsed to ground (via a switching transistor and current limiting resistor) at a rate proportional to speed. This implies to me there is very likely a small positive voltage on this wire when the transistor is "off". At zero speed the transistor should be off.

In other words, if the Nav system updates the map when the wheels are stationary but the vehicle is actually changing location, there is very likely a simple work around to regain full use of the Nav system. If the map position does not change, then it is probably internally programmed to see a finite speed (pulse rate) from the vehicle speed sensor before it will work as a GPS. In the latter case, my theory is in the toilet and I am SOL wrt having a usable system.

To test this theory I tried driving very slow so the vehicle is at least moving but the manual input icons are not yet greyed out. I wanted to see if the map updated as no wires were cut and everything is intact. I could not practically maintain a low enough speed to do this.

[Jon_W]

Hi RhoXS,

I may be able to help you out with this as I do travel on a ferry occasionally.

Can you point me to here you found the wiring diagrams?

[RhoXS]

Thanks Jon. I have been doing a lot of searching on the two Lexus forums. I stumbled into a post that included an attached PDF file. Unfortunately I do not remember where I found it. On the main forum page (so you do not limit the search to just a single vehicle model) search using the term "lockpick". It was a recent post. If you can't find it send me a message with your email address and I will email you the PDF file.

[1990LS400]

RhoXS, I think you could accomplish the same thing by loading your car on a flatbed truck and riding around a parking lot. I doubt if it would cost much if you drove to a tow company's location on a nice day after making arrangements in advance.

It's been years since I had a car on a Washington state car ferry (many times between Anacortes and Vancouver Island) but I thought they chased us out of our cars and required us to go to a seating area on a higher deck.

[NicLX470]

I live here in Southeast Texas and travel on a ferry to get to Galveston often. The GPS does update while on the ferry without the wheels moving. I assume the speed sensor is made ONLY to disable functions while in motion and not to actually judge where the car is. Hence the name...Global Positioning Satellite. There is an antenna picking up signals for several different satellites that tell the car where it is. Speed sensor has nothing to do with the GPS system.

[BillyShaft]

I live here in Southeast Texas and travel on a ferry to get to Galveston often. The GPS does update while on the ferry without the wheels moving. I assume the speed sensor is made ONLY to disable functions while in motion and not to actually judge where the car is. Hence the name...Global Positioning Satellite. There is an antenna picking up signals for several different satellites that tell the car where it is. Speed sensor has nothing to do with the GPS system.

Well, that isn't entirely correct. The speed sensor acts as an internal nav system when satellites are obscured by buildings or in parking garages.

I have had my Nav correctly follow me around inside huge parking garages when the "GPS" indicator turns off from lack of open sky.

[tbear2]

RhoXS, Given that the map updates when stationary on a ferry what is the next step to temporarily remove speed pulses? Switch in a capacitor to ground, etc.?

By the way someone has created a solution for the toyota gps, (http://www.pinemountainfirearms.com/pmf/tundramods/NavSpeedPulse.aspx) but it seems way too complicated. I think you are on to a much more elegant solution path.

[BillyShaft]

Given that the map updates when stationary on a ferry what is the next step to temporarily remove speed pulses? Switch in a capacitor to ground, etc.?

This research is already done and complete. I don't want to discourage additional testing and research, but I think that covering ground already completed has limited benefit and I simply want to point out that it has been done and the T-shirts have been issued.

Additionally, I want to speak up about the assumption that the speed sensor wire is simply the means that Lexus uses to lock out the system. While it does that too, that is not the only or even the primary function of the sensor.

People have removed the speed sensor completely by putting a switch in the line or simply cutting the cable or removing the pin from the connector cable. This does allow you to enter addresses, but it also causes the Nav system to "jerk" and act notchy. While the system does use GPS satellites to determine position, it does not refresh continually but gets updates every so many seconds. The speed sensor acts to fill in the blanks between updates and when the sats are not visible. The additional odd effect I have read is that the spinning wheel indicator on the dash no longer idicates that the car is moving (this may be a hybrid thing only) and was probably info I got from a prius site.

Others have added a switch in the speed sensor input wire and they open the switch when they want to add an address or use the phone keypad or addy book on the MFD. They flip the switch, add the address, and then reset the switch again. This works better than cutting the wire, but there are reports of the car losing its' place on the map and taking up to ten minutes to recover. In both of the above scenarios, butchering your wiring will most certainly void your warranty on the Nav system should a problem later develop. Should you want to attempt this, there are threads about it and how-tos published. Again, this is not new info...

Some versions of Lockpick are assumed to electronically switch open the speed sensor when you are trying to enter an address, and if you read reviews of the product, there are reports that the "add an address" and "phone" features will flash in and out occasionally as the lockpick reconnects the speed sensor to maintain position. Some versions of Lockpick seem to simply do the Nav bypass codes for you, others seem to open the speed sensor. Lots of info out there for an interested researcher. Sounds like a viable solution to me, but the well-documented customer service woes with the company that produces them is a bit of a turnoff to me.

I hope this brief overview illuminates what has already been tested. More information can be found with a google search.

The best solutions in my opinion are (in order of preference):

- Keep pressure on Lexus to remove the lockouts. I am reading now that the 2010 RX allows input while moving. If this is the case, it would be a change of Lexus policy and maybe we can get updates for our systems. I would buy a $300 update without hesitation if it were offered with lockouts removed.

- Using the built in bypass hacks to allow nav access while moving (this requires an appropriate disc version that has not had the feature disabled)

- Use a Lockpick or similar device that helps you do the above hack

- Hire a Denso software engineer or dev who has access to the compiler and the knowledge to remove the I Agree screen and lockouts from the LOADING.KWI files. This would be the most awesome solution in my opinion...it appeals to the lil hacker in me :)