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Discussion Starter · #1 · (Edited)
I decided to re post this in its own DIY thread because there has been alot of pm's and requests for this. This mod has been working well for the past couple months. This was done on my 2014 Toyota Tundra CM SR5 w/ TRD Off Road Entune System.

Problem: is that some Bluetooth functions and navigation address input is disabled when vehicle is in motion. Sometimes navigation options like previous destinations and so forth need to be available for say a passenger that would like to edit or enter addresses or dial a phone number while I dedicate my attention to driving.

The legal stuff: This is what I did, you dont have to do it and if you do and f something up (break your truck, crash, kill someone) at least have the decency to take the responsibility. In fact I am telling you NOT to do this mod, it is for educational purposes only.

The solution: The "grey'd out" navigation options will be available while disabling gps location updating. This means while "grey'd out" options are available your movement will not reflect on the map, so you dont want to drive around like this all the time.

Remove navigation head unit and on the back of the navigation/radio/head unit you will see multiple harnesses.
The 28 pin harness is the one we want, its located on the upper driver side on the back of the head unit. Pin 17 is the Speed sensor wire, it is white and thin gauge.



Follow it up about 6-8 inches as it goes back into the dash, where the split loom starts to cover the bunch of wires cut it open at the end where the black tape is. find the same white wire and cut it in half. Solder a wire to both sides that you just cut and run them to a standard spdt switch (~$4)



Now you will have the ability to tell the navigation unit you are not moving.




Once the address is entered and route selected, simply flip the switch to connect the Speed sense wire back and give the navigation a couple seconds to catch up to your gps location...... thats it.
 

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Subd for future use...
 

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Hey where did you get those switches? I've been looking for dual ones but cant find any.
 

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Discussion Starter · #5 ·
i bout some really small ones from frys electronics i think it was, and i dremeled out the knock out myself. thats all custom by hand no premade dual switch there.

you can however get dual switches on ebay, I ordered some just to try out, coming from china though.
 

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Nav lockout Bypass DOES NOT work on my 2014 Platinum

I followed the instruction here to a tee. I used lighted switches so I can see when they are on and off so to make sure I don't send any stray power to the VSS wire I isolated the VSS disconnect through a relay. It disconnects the wire when switch is on and reconnects it when the switch is off. I also did the reverse camera mod and that works great.

As far as the VSS interrupt. As soon as you flick the switch I got warning lights on my dash for things like ABS, Blind Spot Sensor, and a few other lights that freaked me out. BUT even with all the errors the nav. grey out was working just like normal, totally greyed after 2-3 MPH. The only cure for the warning lights was to stop the truck turn it off and restart. One warning light that is still on is my airbag light. I have the Toyota data cable and software so I am sure I will be able to clear that error code. I noticed that the thin white VSS wire is twisted together with the pastel green/blue wire right next to it. Figuring this was another speed wire, maybe for the GPS, I also made my relay open that wire when the switch is on. My relay is a DPDT so all wires are separate. When the switch is on the white and the light green are broken (but not tied together of course). The funny thing is that now that I am interrupting BOTH at the same time I get no errors when the switch is on. The problem is it also seems to still have NO EFFECT on the Entune grey out issue. Those seem to be the right wires but I am unsure why this does not work. My truck is a 2014 Platinum CM production date is 09/13 and I have the original firmware with no updates shown.

Maybe I need to build the speed circuit like the 4 Runners??
 

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Discussion Starter · #8 ·
try without relay on just the white wire indicated in first post. i don't recall if it's twisted worth a green wire or not. i doubt there's a difference in trim vehicles as long as it's the same navigation head unit.
 

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I was thinking of trying that as well but I really don't thank that is the issue. The thing is the second the relay opened that white wire (while moving) all kinds of error codes popped up so the relay IS opening the wire. Also when the truck is stationary the interruption of the white wire had no effect. The truck must know it's moving still and the difference freaks it out. The fact that the errors stopped when I also interrupted the green wire tells me that one is tied in somehow. The white and green (5th & 6th over, top row) are twisted and taped together and are definitely associated in some way.
 

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try without relay on just the white wire indicated in first post. i don't recall if it's twisted worth a green wire or not. i doubt there's a difference in trim vehicles as long as it's the same navigation head unit.

Don't know if it matters, but a Platinum has the JBL. Might be different.
 

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I am not really sure how to draw it out but it is real simple. When the relay coil is energized it opens the white wire, with no power to the relay the contacts are closed. The same as a switch really. Before install I tested it 8 ways to Sunday to make sure that the wires don't cross in any way. I wanted to be real sure to be careful with the sensitive VSS wire. I even put a drop resistor on the coil power to keep it from ever overheating and contact bounce.
 

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Discussion Starter · #13 ·
drop resistor or diode? there should be contacts labeled if its a standard automotive relay like a bosch. 85, 86, 87, 87a, 30.... that kind of thing. those relays can be tricky with finer electronics. I understand the desire to have a lighted switch, but consider youd know pretty quick if you forgot to flip the switch because your location wont move on the map.

I would really consider finding the pin out for that particular model head unit. not doing so could lead to problems and even damage. you could test the wiring more accurately with a multimeter, the vss should be ac and fluctuate as the vehicle moves, not just rpm's in neutral. you could only tap into the white or green or whatever color you think is the vss and attache multimeter to it, drive and watch it rise as your speed rises consistently. if it doesnt then thats not the vehicle speed sensor wire.
 

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drop resistor or diode? there should be contacts labeled if its a standard automotive relay like a bosch. 85, 86, 87, 87a, 30.... that kind of thing. those relays can be tricky with finer electronics. I understand the desire to have a lighted switch, but consider youd know pretty quick if you forgot to flip the switch because your location wont move on the map.
The relay I used is actually a smaller, more stable board mount relay meant for integrated circuits. It has one coil but two separate NC and NO pairs. I used a 220 ohm resistor in line with the coil to lessen the current going to the relay. I did kind of the same thing on my tailgate lock mod since the actuator was driven very hard to turn a small lock.

I would really consider finding the pin out for that particular model head unit. not doing so could lead to problems and even damage. you could test the wiring more accurately with a multimeter, the vss should be ac and fluctuate as the vehicle moves, not just rpm's in neutral. you could only tap into the white or green or whatever color you think is the vss and attache multimeter to it, drive and watch it rise as your speed rises consistently. if it doesnt then thats not the vehicle speed sensor wire.

I agree that the pin outs could be different. It looked just like the one you have pictured. At least the wires you have labeled for VSS, reverse, etc. I made sure of that. Even your photo shows the little green wire I am talking about. I will have to hook up a meter one day when I have time to test the VSS output pulse.
 

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NO, NO, that would be stupid. I used to be an electronic field tech and long, long ago a car alarm/stereo/cruise control, etc. installer. I used a 220 ohm in series with the relay coil, not the contacts. The relay coil was lower impedance and the resistor was just to drop current a bit. The circuit for the VSS is simply Opened/Closed with no extra resistors, diodes, etc. I am going to try and manually break and close the connection to see if I get different results but I think they made a change with Platinum Models. I do have the JBL system, blind spot sensors, electronic adj. headlights, etc. that many trucks don't have.
 

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right on. seriously just try the vss on a switch. pull relay out, its a neat idea though to have a lighted switch but may be more work then necessary.
I have nothing to lose so I will try test with regular switches on the white and/or blue wires alone. I will try just the white first. Who knows maybe the relay contacts are picking up EMF and sending it to the VSS somehow.
 

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Discussion Starter · #19 ·
you know, looking at the pic in first post and trying to remember... I dont think the white wire is twisted with anything, im thinking you have a completely different model head unit that works differently then the panasonic unit I have. if you tell me the model number I might be able to get the pin out from my toyota guy.
im pretty certain the issue is your rela5 as a diode should be used to prevent the spike in

voltage and to reduce the emf. I just did a garage project where I took a small battery charger (like what you would get at pep boys to maintain your car battery or even start the car when the batter dies) I then took a 12vdc battery from a home alarm system and wanted to wire up a radio so that when I turn off the wall outlet feeding the battery charger it would maintain memory on the radio. but when the charger was on it would not only charge the battery like the circuit in a car but provide ignition switched to the radio. in essence creating a circuit that acts just like a car..... well it proved to be difficult because having only 2 relays and wire I wasnt able to simply connect ground and + to trigger the relay and have the charger supply the source 12vdc+ that goes on to the radio and battery without it not wanting to shut off when charger lost its ac supply. I did however get it to work using one relay and a diode. im pretty sure something is leaking or back feeding onto the vss wire, thats the only thing that makes sense. that and the fact you have a different model radio then me. I always check and double check my wiring to make sure its what I think it is, I would simply have a helper connect and disconnect the vss leads while I drive to see how it reacts, then put all the other components in like the switch and diode and relay and resistor and so on. just keep it basic.

sorry for going on and on, its frustrating not being able to talk technically with other people that have similar or more knowledge then me, so I take advantage when I can.
 

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I agree that we may have a different radio. But the funny thing is that the wire colors and locations are exactly the same on the harness. If you look at your photo of the harness the white VSS wire and they light green/blue one next to it are the ones that start twisting together after a few inches. AS a test today I pulled the part of my circuit I could get to without removing the radio (I have it to sitting right behind the cig lighter panel). I cut one of the wires making the loop extending the white wire to the relay. Cutting the wire today had no effect on the car. I may have something different for sure. I will find the model and see what's what a little later this afternoon.
 
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