NAV and Bluetooth bypass DIY
12-28-08, 08:19 PM
#16
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A wireless DIY solution to Nav. overide
Nomi’s directions on cutting the brown wire #4 to the install a switch is a wonderful solution to being able to use the Navigation system while driving. I have added a slightly more elegant switch idea: a wireless switch.
Remember, you are on your own with this DIY project. I make no claims that you know what you are doing - or I for that matter! <grin>
After some research I found a small 12vdc switch - Logisys RM01. I ordered it from Directron.com http://www.directron.com/rm01.html(Wireless Remote Control ADP-RM01), the cost was $12.99 plus shipping. However I just noticed they are out of stock. Here is another source: http://www.outletpc.com/c7235.html The switch is typically used to provide a wireless on/off of a 12vdc power source. I had to modify the circuit board to remove the sending of 12vdc, I just wanted an isolated, non-powered, on / off.
I cut the brown wire as per Nomi’s directions, spliced in my switch, located a 12vdc power source in the rear compartment and bingo I have a wireless on / off that allows me to use the Nav while driving.
Here are some pictures with more details.
Here is the little wireless switch:
Here is the small key fob:
Here is the circuit board cut with a new wire connected. I used a Dremel Tool to cut the trace. This cut takes the 12vdc + away from the pin and simply makes the new connection powerless. There were two black "ground" wires on the front side of the board. I cut one and simply soldered it to the isolated pin. The white wire on the front that would have been 12vdc + out is now also without power. These two wires are the wires I spliced into the brown wire on connector. I did twist these two wires together as a pair so I would not later confuse this black wire with the black ground wire.
Here are the black and white wires spliced into the brown. I soldered them in, taped them up, then reused the black banding tape that surrounded the bunch of wires at the connector.
Next is finding a 12vdc source in that area. I choose to use the 12vdc coming off the right side storage area light. I snaked a wire down (via the access panel) into where the Nav unit is and connected it to the red 12vdc power wire on the switch and the other end to the light blue wire on the light connector.
I choose to use one of the Nav unit's connecting bolts to connect the black ground wire of the switch.
Here is what it looked like all connected up. The blue wire is the wireless antenna:
Finally I put the switch into some plumbing insulation and put it out of the way in the corner behind the Nav unit.
Remember, you are on your own with this DIY project. I make no claims that you know what you are doing - or I for that matter! <grin>
Remember, you are on your own with this DIY project. I make no claims that you know what you are doing - or I for that matter! <grin>
After some research I found a small 12vdc switch - Logisys RM01. I ordered it from Directron.com http://www.directron.com/rm01.html(Wireless Remote Control ADP-RM01), the cost was $12.99 plus shipping. However I just noticed they are out of stock. Here is another source: http://www.outletpc.com/c7235.html The switch is typically used to provide a wireless on/off of a 12vdc power source. I had to modify the circuit board to remove the sending of 12vdc, I just wanted an isolated, non-powered, on / off.
I cut the brown wire as per Nomi’s directions, spliced in my switch, located a 12vdc power source in the rear compartment and bingo I have a wireless on / off that allows me to use the Nav while driving.
Here are some pictures with more details.
Here is the little wireless switch:
Here is the small key fob:
Here is the circuit board cut with a new wire connected. I used a Dremel Tool to cut the trace. This cut takes the 12vdc + away from the pin and simply makes the new connection powerless. There were two black "ground" wires on the front side of the board. I cut one and simply soldered it to the isolated pin. The white wire on the front that would have been 12vdc + out is now also without power. These two wires are the wires I spliced into the brown wire on connector. I did twist these two wires together as a pair so I would not later confuse this black wire with the black ground wire.
Here are the black and white wires spliced into the brown. I soldered them in, taped them up, then reused the black banding tape that surrounded the bunch of wires at the connector.
Next is finding a 12vdc source in that area. I choose to use the 12vdc coming off the right side storage area light. I snaked a wire down (via the access panel) into where the Nav unit is and connected it to the red 12vdc power wire on the switch and the other end to the light blue wire on the light connector.
I choose to use one of the Nav unit's connecting bolts to connect the black ground wire of the switch.
Here is what it looked like all connected up. The blue wire is the wireless antenna:
Finally I put the switch into some plumbing insulation and put it out of the way in the corner behind the Nav unit.
Remember, you are on your own with this DIY project. I make no claims that you know what you are doing - or I for that matter! <grin>
01-07-09, 04:02 PM
#17
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I am curious about how the Nav system really behaves with the speed signal permanently interrupted.
I would think it still should be a fully functioning GPS and display map progress as smoothly and accurately as any stand alone dash top unit. Unless it loses the GPS signal because of a tunnel etc., it should continue to work fine. In fact, the GPS satellite based speed calculation is probably much more accurate than the vehicle speed signal. For this reason, I cannot understand why some say it does not work with the speed signal interrupted. Based on a number of years experience with Garmin Streetpilots, there is rarely a need for dead reckoning using the vehicle speed signal to continue to estimate its position. In other words, I just want to permanently remove the speed signal and never again deal with it.
I would think it still should be a fully functioning GPS and display map progress as smoothly and accurately as any stand alone dash top unit. Unless it loses the GPS signal because of a tunnel etc., it should continue to work fine. In fact, the GPS satellite based speed calculation is probably much more accurate than the vehicle speed signal. For this reason, I cannot understand why some say it does not work with the speed signal interrupted. Based on a number of years experience with Garmin Streetpilots, there is rarely a need for dead reckoning using the vehicle speed signal to continue to estimate its position. In other words, I just want to permanently remove the speed signal and never again deal with it.
01-07-09, 05:24 PM
#18
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I am curious about how the Nav system really behaves with the speed signal permanently interrupted.
I would think it still should be a fully functioning GPS and display map progress as smoothly and accurately as any stand alone dash top unit. Unless it loses the GPS signal because of a tunnel etc., it should continue to work fine. In fact, the GPS satellite based speed calculation is probably much more accurate than the vehicle speed signal. For this reason, I cannot understand why some say it does not work with the speed signal interrupted. Based on a number of years experience with Garmin Streetpilots, there is rarely a need for dead reckoning using the vehicle speed signal to continue to estimate its position. In other words, I just want to permanently remove the speed signal and never again deal with it.
I would think it still should be a fully functioning GPS and display map progress as smoothly and accurately as any stand alone dash top unit. Unless it loses the GPS signal because of a tunnel etc., it should continue to work fine. In fact, the GPS satellite based speed calculation is probably much more accurate than the vehicle speed signal. For this reason, I cannot understand why some say it does not work with the speed signal interrupted. Based on a number of years experience with Garmin Streetpilots, there is rarely a need for dead reckoning using the vehicle speed signal to continue to estimate its position. In other words, I just want to permanently remove the speed signal and never again deal with it.
When I activate the NAV override, the GPS thinks it's standing still. It's like it's turned off.
When I deactivate the NAV override (turning the GPS back on) , the screen display thinks I'm where I was it was turned off. It shows me off the road, in the wrong place. Then it takes a few seconds for the GPS to reorient and the screen shows me in the correct place and everything is back to normal.
01-09-09, 06:23 AM
#19
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I am curious about how the Nav system really behaves with the speed signal permanently interrupted.
I would think it still should be a fully functioning GPS and display map progress as smoothly and accurately as any stand alone dash top unit. Unless it loses the GPS signal because of a tunnel etc., it should continue to work fine. In fact, the GPS satellite based speed calculation is probably much more accurate than the vehicle speed signal. For this reason, I cannot understand why some say it does not work with the speed signal interrupted. Based on a number of years experience with Garmin Streetpilots, there is rarely a need for dead reckoning using the vehicle speed signal to continue to estimate its position. In other words, I just want to permanently remove the speed signal and never again deal with it.
I would think it still should be a fully functioning GPS and display map progress as smoothly and accurately as any stand alone dash top unit. Unless it loses the GPS signal because of a tunnel etc., it should continue to work fine. In fact, the GPS satellite based speed calculation is probably much more accurate than the vehicle speed signal. For this reason, I cannot understand why some say it does not work with the speed signal interrupted. Based on a number of years experience with Garmin Streetpilots, there is rarely a need for dead reckoning using the vehicle speed signal to continue to estimate its position. In other words, I just want to permanently remove the speed signal and never again deal with it.
Anyone else with ideas, please jump in...
01-09-09, 07:45 PM
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It has been established interrupting the vehicle speed signal normally input to the Nav system will restore the ability to manually enter data when under way. This fact is taken advantage of by products such as Lockpick3 and some hardware “hacks”. Interrupting this signal also has the negative effect of causing the Nav system to stop navigating, even though it is a full function GPS with no justifiable need for an external speed signal. Therefore, none of these techniques are true elegant solutions that can be implemented once and then forgotten. They all cause the Nav system to stop navigating temporarily and some action must be taken to restore it.
I was thinking about this and some thoughts came to mind.
I made two assumptions for how the speed signal is probably internally used by the Nav system based on what I would have done if I was the Engineer that designed the system:
1. The nav system probably does not normally use the external speed sensor signal. It probably only uses GPS based data for calculating position and updating the map unless the GPS data is not available. Only then does it revert to the vehicle speed sensor signal for temporary dead reckoning.
2. The speed sensor signal has a secondary function (maybe primary in the warped sick mind of a lawyer). This secondary function is to lock out manual input to the Nav system once the vehicle exceeds some very low speed. There must be some finite threshold value, albeit very low, so the system does not inadvertently lockout input when not in motion (i.e. avoids “chatter” by using a small “dead band”). As a deterrent to simply removing this signal to override the manual input lockout, the Nav system is programmed to stop navigating, even using GPS derived position information, if it sees no input from the vehicle speed sensor input.
If I was brave enough to experiment (I am not) with my brand new three week old 2009 RX350, I would try one of the following two experiments. Using a good high impedance digital DVOM to measure the voltage on the speed signal line at rest might help focus on which might be the best method below.
1. I would take a relatively large value electrolytic capacitor and connect it between the wire containing the speed signal and ground. Doing this would avoid having to cut the wire and it would maintain a mostly constant positive DC voltage on the input to the Nav system at no higher than the voltage it normally sees. This should be relatively safe to do (with respect to potentially damaging something) and might just simulate a constant zero speed but intact input to the system. Depending on how the speed signal going to the Nav system is isolated from other circuits, it might be necessary to insert a diode behind it (this means cutting the wire) to avoid effecting other functions utilizing the vehicle speed sensor. This approach assumes the vehicle speed sensor signal is a positive DC voltage that is interrupted at a rate proportional to the vehicles speed. There might even be a positive constant DC voltage present at zero speed. OR
2. I would cut the wire containing the speed signal and then ground the end going to the Nav system (insulate and secure the end coming from the wiring harness). It is possible the vehicle speed signal is a negative/grounded signal that is interrupted with a small positive DC voltage at a rate proportional to the vehicles speed. At zero speed it is possible the speed signal input is grounded.
If my car was not so new and out of warranty I would be experimenting as I think one of these approaches may put a quick elegant end to this foolishness. Anyway, I hope these thoughts provide some useful ideas for someone braver than me.
I was thinking about this and some thoughts came to mind.
I made two assumptions for how the speed signal is probably internally used by the Nav system based on what I would have done if I was the Engineer that designed the system:
1. The nav system probably does not normally use the external speed sensor signal. It probably only uses GPS based data for calculating position and updating the map unless the GPS data is not available. Only then does it revert to the vehicle speed sensor signal for temporary dead reckoning.
2. The speed sensor signal has a secondary function (maybe primary in the warped sick mind of a lawyer). This secondary function is to lock out manual input to the Nav system once the vehicle exceeds some very low speed. There must be some finite threshold value, albeit very low, so the system does not inadvertently lockout input when not in motion (i.e. avoids “chatter” by using a small “dead band”). As a deterrent to simply removing this signal to override the manual input lockout, the Nav system is programmed to stop navigating, even using GPS derived position information, if it sees no input from the vehicle speed sensor input.
If I was brave enough to experiment (I am not) with my brand new three week old 2009 RX350, I would try one of the following two experiments. Using a good high impedance digital DVOM to measure the voltage on the speed signal line at rest might help focus on which might be the best method below.
1. I would take a relatively large value electrolytic capacitor and connect it between the wire containing the speed signal and ground. Doing this would avoid having to cut the wire and it would maintain a mostly constant positive DC voltage on the input to the Nav system at no higher than the voltage it normally sees. This should be relatively safe to do (with respect to potentially damaging something) and might just simulate a constant zero speed but intact input to the system. Depending on how the speed signal going to the Nav system is isolated from other circuits, it might be necessary to insert a diode behind it (this means cutting the wire) to avoid effecting other functions utilizing the vehicle speed sensor. This approach assumes the vehicle speed sensor signal is a positive DC voltage that is interrupted at a rate proportional to the vehicles speed. There might even be a positive constant DC voltage present at zero speed. OR
2. I would cut the wire containing the speed signal and then ground the end going to the Nav system (insulate and secure the end coming from the wiring harness). It is possible the vehicle speed signal is a negative/grounded signal that is interrupted with a small positive DC voltage at a rate proportional to the vehicles speed. At zero speed it is possible the speed signal input is grounded.
If my car was not so new and out of warranty I would be experimenting as I think one of these approaches may put a quick elegant end to this foolishness. Anyway, I hope these thoughts provide some useful ideas for someone braver than me.
Last edited by RhoXS; 01-10-09 at 10:47 AM.
01-10-09, 10:00 AM
#21
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Great ideas RhoXS! But, like you, I'm not sure I want to go any further than I have in hacking the system. I do hope that ALL LEXUS owners will tell Lexus when they send the new purchase survey that we want our GPS back. At the very least when the passenger seat detects a passenger. I don't see any more liability than the portable GPS companies have. Hey, if you are stupid enough to not pay attention to your driving, don't drive! <grin>
01-11-09, 05:08 AM
#22
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Lexus has been hearing, and ignoring, this for years. Its a big dissatisfer evidenced by all the threads about hacks and after market products to get around it. There are web sites like lexusoverride.com and lexusisnotmymother.com that are dedicated to this. Rather than listen, Lexus has actually gone to lengths to defeat some of the early workarounds in later model releases. You are right, they don't have any more liability than any other GPS maker/supplier, they just choose to deal with that risk differently. Biggest complaint for us with both our G an R.
01-24-09, 02:58 PM
#24
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Now that I've used the nav hack I can report that when I turn off the speed sensor line in about 1 minute it goes gray again and I have to turn it back on then off... anyone else encounter this with any switch hack?
02-26-09, 08:19 AM
#25
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JS5Owner -- Does this mean that the nav hack only works for a minute before being disabled again?
02-28-09, 07:13 AM
#26
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What I've experienced is that you've got to turn off (i.e. go back to the line connected) the hack, then turn on (i.e. disconnect the line) the hack again. As I wrote a few posts back, there must be some signal that we are missing. But I can tell you that this is better than NOT controlling the NAV while driving. Ya just have to enter things in quickly! <grin>
02-28-09, 11:40 AM
#27
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I read somewhere that the nav unit is sensing the car movements via both the speed sensor and the GPS itself. This could be the reason why all icons will be grayed out after a short time.
How much time exactly do you have? I want to do this to my new 09 RX 350 with a 8.1 dvd, but don't want to cut wires yet. I wonder if anyone know of a male/female adapter/connector that fits the connector on the DVD unit which will allow me to mod the wires without actually cutting the original wires in the car.
How much time exactly do you have? I want to do this to my new 09 RX 350 with a 8.1 dvd, but don't want to cut wires yet. I wonder if anyone know of a male/female adapter/connector that fits the connector on the DVD unit which will allow me to mod the wires without actually cutting the original wires in the car.
03-04-09, 08:53 AM
#28
It takes about a minute for the system to realize that car is moving and the speed signal is missing so it ignores the speed signal and starts using the GPS for 100% of the function. Normally it takes me less time than this to input the address so I don’t mind it. The 2nd part of the same equation is that if you forget to flip the switch after you have inputted the address GPS will go back to normal function and start tracking the car. I have been using this for several months now without any issues. The car has been to the dealer couple of times for oil changes but they have never noticed any thing
03-04-09, 11:16 AM
#29
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I have a plug and play kit to unlock the nav on our GS. it times out after about 45 sec (the system locks out again). On the few times i've not been finished with the input, i just flick the kit off for a few seconds and then back on and it unlocks for another 45 seconds and I can pick up the input where I left off. Don't have to start over. I imagine this would work the same way????
On our RX we used the lockpick from coastaltech. After about 45 secs or a minute, the navi briefly grays out for maybe 3 secs then unlocks again. The car is trying to regain control as others have posted. I don't know what signals it's using. But when the ar trys to take the navi signal back, lockpick re-engages on it's on and unlocks the navi again without any intervention. for $99, it was worth it for us. Love the wireless switch idea, never could do it myself.
On our RX we used the lockpick from coastaltech. After about 45 secs or a minute, the navi briefly grays out for maybe 3 secs then unlocks again. The car is trying to regain control as others have posted. I don't know what signals it's using. But when the ar trys to take the navi signal back, lockpick re-engages on it's on and unlocks the navi again without any intervention. for $99, it was worth it for us. Love the wireless switch idea, never could do it myself.