DIY: All NAV Functions All The Time without Firmware Downgrade!

[chiplee]

I'm having a problem now with my SPG.

I have a VSC TRAC and VSC OFF light with the Check engine light on.

Everything seemed to be working fine until Installed a VAIS SL2Vi Video ipod interface. I had to ground the parking brake wire to get the ipod video to show on the move, and the SPG had to be working also. I had both the spg and the P-brake grounded to the same ground wire, which was the negative wire on the cigarette lighter, maybe dumb, not sure.

Anyway, it all worked beautifully for a day or so, then the CEL and other lights came on and now my nav doesn't give turn by turn guidance. At one point my auto up/down driver window switch didn't "auto" up down. I had to hold it to get the window to move. I've reset the ecu and unhooked the SPG. The lights come back on within a mile and the nav acts like it doesn't know where I am. Have I damaged something?


On and here are the pictures someone asked for



It's worth noting in this next picture, that if you're going to install the switch in one of the plugs like I did, DON'T cut so much material out of the back of the plug to fit the switch in there. You will ruin the stiffness of the thing and make it fit loosely in its hole. I cut too much out in this pic and will have to reinforce it somehow to make it fit snuggly again.

[wileetundra]

Originally Posted by chiplee

I'm having a problem now with my SPG. I have a VSC TRAC and VSC OFF light with the Check engine light on. Everything seemed to be working fine until Installed a VAIS SL2Vi Video ipod interface.

The SPG has nothing to do with VSC TRAC or the CEL. The only output from the SPG device is a pulsing +12VDC signal on the green speed pulse wire so the only way that this could cause problems for your truck or other accessories would be if you wired it up wrong to feed the speed pulse directly into your vehicle ECU or other circuits. Even if you did wire it up wrong or if your wires were shorted with other wires, then the IC chip inside the SPG would burn out quickly and/or you would blow a fuse in your vehicle and the SPG would be dead. Since the SPG worked fine before you installed the ipod interface then it is safe to assume that your current problem is with the ipod interface or the wiring changes that you made during the ipod installation. I am guessing that your CEL might be unrelated and just a coincidence.

Originally Posted by chiplee

I had to ground the parking brake wire to get the ipod video to show on the move, and the SPG had to be working also. I had both the spg and the P-brake grounded to the same ground wire, which was the negative wire on the cigarette lighter, maybe dumb, not sure.

You can't use the SPG and the video device at the same time, at least not on the newer NAV units. The NAV insists on the vehicle being completely stopped to display video on the front screen and the SPG generates a speed pulse which fluctuates between 0-1 mph, so the NAV would detect a slight motion from the SPG and disable the video briefly during each pulse. When you are using video on the NAV you need to put the SPG in factory mode. There isn't any reason to keep the SPG enabled during a movie anyway since you shouldn't need to use the NAV functions while watching a movie.

I have a toggle switch hooked to the parking brake input on my NAV unit. I can switch it to on, off, or factory mode and I have been using it for several months in all 3 positions and the parking brake mode doesn't effect my NAV or SPG in any way.

Ground is common throughout the vehicle so it shouldn't matter where you grounded each accessory as long as you are sure that you have a true ground connection. Some wires are only grounded part of the time but then switched to + voltage or other signals while in use, and some metal parts in the truck are not grounded at all so you have to be careful. Generally the ground on the cigarette or accessory outlet is a good choice.

Originally Posted by chiplee

Anyway, it all worked beautifully for a day or so, then the CEL and other lights came on and now my nav doesn't give turn by turn guidance. At one point my auto up/down driver window switch didn't "auto" up down. I had to hold it to get the window to move. I've reset the ecu and unhooked the SPG. The lights come back on within a mile and the nav acts like it doesn't know where I am. Have I damaged something?

You should take your vehicle to a local auto parts store and borrow their OBD / CAN meter to read the trouble codes stored in your ECU. This will tell you why the CEL is on and how to fix it.

In my 2007 Tundra the only auto window function is auto-down for the driver window and this circuit has nothing at all to do with the NAV or SPG.

Your map scrolling and guidance functions may be less accurate while the SPG is enabled. This is because most NAV units rely on the speed pulse to enhance the accuracy of the GPS signal, so when you feed it a bogus speed pulse then the maps might scroll less smoothly or it might get your actual position confused and not give accurate guidance. This is why the SPG uses a toggle switch: put it in bypass mode to unlock and use the functions while in motion, then flip it back to factory mode when you are done and all is fine.

Not making fun of your situation but the odd symptoms reminded me of a problem that my father-in-law once reported to me about his home security system. He said that the alarm system worked fine but it would go off every time he added or removed something from his kitchen refrigerator. I thought he was kidding but he was dead serious. I installed that system myself so I knew for sure it was not connected to the refrigerator in any way, yet I could hear his alarm going off over the phone so I figured I had to check it out. After some troubleshooting it turned out that he had accidentally ripped off the alarm wire that was connected to one of the kitchen window sensors and he tried to patch it back up but he did a poor job and the connection was very loose. That particular wire ran through some conduit that went behind the refrigerator, and his refrigerator was not properly leveled, so whenever he would bump the refrigerator it would press against the conduit which in turn vibrated the alarm sensor wire just enough to break the connection briefly and set off the alarm.

[chiplee]

Thanks a bunch for the detailed reply. Yeah my 4Runner is on an extended warranty and I don't think this problem is related to either the ipod interface or the SPG any more either. I've returned the truck back to stock nav and reset the zero point calibration in the VSC computer several times and it still throws the code in about a half mile of driving.

The only thing I saw something wrong with in your reply is the assertion that you have to be dead stopped to view video. That must be a later generation thing, but for the VAIS SL2Vi you have a "picture" button on the touch screen much like the address input buttons. while moving, this button is grayed out, unless you switch the SPG to 0-1mph mode, at which time it raises, and you can indeed watch ipod video while driving, as long as the P-brake wire is also grounded.
here's a video of it all working, incase you don't believe me, lol YouTube - 2004 4Runner Factory Nav Ipod integration

Also, I read every word of your install site for the SPG so I expected less accurate guidance with the SPG installed. I now have terrible guidance with the SPG completely removed. I don't get turn by turn guidance at all and the nav orientation arrow (arrow that represents your position on the map I mean) spins around slowly trying to figure out how you're oriented. Ocassionally the buttons that are supposed to be grayed out will become available for a moment while moving, and it does this WITHOUT activating the SPG switch. It seems somehow related to the fact that I drove the vehicle significant distances with the SPG on so I could test out and then watch ipod videos on the move. The nav doesn't tell me about up coming turns or depict the split screen. Oh and now the auto up down window switch is working but the sun roof is not. It will open but I have to hold it.

I'll read the codes and see what it's saying but I'm going to let the dealer work on it.

[chiplee]

Code reader at autozone said VSS

Vehicle speed sensor caused by

1. loose connection
2. Bad ground
3. Bad VSS

Is there a VSS fuse? lol

I'm having a little trouble convincing myself my tampering with the NAV speed pulse input didn't do this.

[wileetundra]

Originally Posted by chiplee

Code reader at autozone said VSS

Vehicle speed sensor caused by

1. loose connection
2. Bad ground
3. Bad VSS

Is there a VSS fuse? lol

I'm having a little trouble convincing myself my tampering with the NAV speed pulse input didn't do this.

If you fed the SPG signal back into the vehicle ECU then this could cause a problem with the VSS. Several people made this mistake when wiring up the device or the switch. Make sure the factory speed pulse is disconnected from the NAV and the SPG pulse goes directly into the back of the NAV unit.

Also, make sure you tapped into the speed sensor wire directly behind the NAV unit. On some vehicles the speed sensor also feeds other devices like your audio system, dashboard computer, etc. so if you tap into the speed wire somewhere else then you could be feeding the bogus speed pulse to multiple devices which could cause some problems.

Also, if you removed the SPG and your problem still remains then I don't see how it could be caused by the SPG, unless maybe you fed enough voltage or current back into the VSS circuit to burn it out. If you want to send me your wiring diagram and some photos of your wiring for the switch and SPG then I might be able to help you further. There are nearly 100 of these units in use for all sorts of 2004-2008 vehicles and nobody reported any problems like this so I can't imagine what else it could be other than a wiring issue.

[chiplee]

Originally Posted by wileetundra

If you fed the SPG signal back into the vehicle ECU then this could cause a problem with the VSS. Several people made this mistake when wiring up the device or the switch. Make sure the factory speed pulse is disconnected from the NAV and the SPG pulse goes directly into the back of the NAV unit.

Also, make sure you tapped into the speed sensor wire directly behind the NAV unit. On some vehicles the speed sensor also feeds other devices like your audio system, dashboard computer, etc. so if you tap into the speed wire somewhere else then you could be feeding the bogus speed pulse to multiple devices which could cause some problems.

Also, if you removed the SPG and your problem still remains then I don't see how it could be caused by the SPG, unless maybe you fed enough voltage or current back into the VSS circuit to burn it out. If you want to send me your wiring diagram and some photos of your wiring for the switch and SPG then I might be able to help you further. There are nearly 100 of these units in use for all sorts of 2004-2008 vehicles and nobody reported any problems like this so I can't imagine what else it could be other than a wiring issue.

I've suspected my wiring from the beginning. Never meant to imply otherwise or put you on the defense of your device. I fully intend to re-install it after the VSS is replaced. I'll just be a little more careful on a couple accounts.

My previous ipod "integration" was via FM Modulator that I plugged in to the console cigarette lighter. I was thoroughly dissatisfied with the performance of the FM modulated IPOD device so I didn't really use it much. It had slipped my mind that back when I did use it, I often had to jiggle the cigarette lighter adapter for the Belkin unit to get it to charge the ipod. This is the switched 12v source I selected for the SPG install. I know I wired it correctly but I think the power or ground was intermittent/shorted and somehow jacked up the VSS. I have no issue with taking it to the dealer 'cause they owe me a fix on the cigarette lighter anyway, lol. I'll let you know how I make out.

[wileetundra]

Originally Posted by chiplee

I've suspected my wiring from the beginning. Never meant to imply otherwise or put you on the defense of your device. I fully intend to re-install it after the VSS is replaced. I'll just be a little more careful on a couple accounts.

No problem. Not defensive, just trying to reassure you that it was not likely to be a serious problem and should be easily fixed with a review of the wiring. I do as much as possible to help everyone with NAV mods but there is a limit to how much you can troubleshoot over the web. Keep us posted on what you find.

[chiplee]

Originally Posted by wileetundra

No problem. Not defensive, just trying to reassure you that it was not likely to be a serious problem and should be easily fixed with a review of the wiring. I do as much as possible to help everyone with NAV mods but there is a limit to how much you can troubleshoot over the web. Keep us posted on what you find.

wow, fast reply. I was editing that post while you posted. Please check the update if you get a minute. thanks again for all your help.

[low c1500]

Question?

I have a few O2 sensor simulators, they are a little inclosed ciruit that has a +12 and ground wire, and the output wire toggles between 0.3v and 0.65v (every second or so), would this work to fool the NAV as a speed input?

[wileetundra]

Originally Posted by low c1500

Question?

I have a few O2 sensor simulators, they are a little inclosed ciruit that has a +12 and ground wire, and the output wire toggles between 0.3v and 0.65v (every second or so), would this work to fool the NAV as a speed input?

I am not sure but I don't think so. I believe the pulses have to span a wider voltage gap with the lowest peak going to 0 volts. During my testing it only worked when I got it to 0 volts and even negative voltage worked if I kept the pulses short, however a few people had some issues with capacitors burning out so we modified the circuit design again.

Also, the pulse duration should be slower, like once every 4-6 seconds, to minimize the speed equivalent in the NAV unit. If the pulses are too wide or too fast then the NAV will calculate a faster speed and lockout the functions. If you decide to try it then by all means let us know how it works. Just be careful not to fry your NAV unit or ECU...

[Crewmadmax]

I just bought one from you and im looking forward to installing it.

[mnlawyer]

I got one, installed it, and it works great. Thanks WileETundra! Best $50 I ever spent. My wife has found all kinds of neat things to do with the nav that I probably would have never found.

It makes you wonder why Toyota can install seat sensors sensitive enough to detect my briefcase in the passenger seat, but cannot correlate a passenger with full nav functionality.

[Crewmadmax]

If I am Installing it without a switch.

Maybe I missed it, but am I suppose to "cut" the white wire and connect the green to it or am I suppose to strip some of the white back and connect to it?

If I am suppose to cut the white wire, do I connect the green to the white wire going to the ECU or the harness plugging into the NAV? Do I cap off the one I don't use?

[wileetundra]

Originally Posted by Crewmadmax

If I am Installing it without a switch.

Maybe I missed it, but am I suppose to "cut" the white wire and connect the green to it or am I suppose to strip some of the white back and connect to it?

If I am suppose to cut the white wire, do I connect the green to the white wire going to the ECU or the harness plugging into the NAV? Do I cap off the one I don't use?

You really need to use an SPDT switch to ensure that your maps will scroll smoothly. I don't include the switch with the unit because everyone has their own preference for the size, color, location, and type of switch. I just sent you the detailed instructions via email which include a high-res wiring diagram to clarify this for you. PM or email me if any questions.

[zpaul]

Wilee you Da Man!
Just installed your gadget with the switch. Did not have much time to play, but now with the flip of the switch I can Finlay do whatever I want.
Chiplee, thanks for the switch! Looks great, works too
Here is the set up: