I, like many others here, have noticed the lag in the TL navigation system (indicates crossing of a street intersection after you have actually passed it). Tonight I may have stumbled across a solution, although I need some other members here to test it to see if you get the same result.

Thinking about this problem, I was wondering if the lag could be related to processing speed of the nav computer. I decided to try driving for a while with it in "North Up" mode (which I ordinarily don't do) to see if it might be more accurate since it didn't have to continually rotate the map image in this mode. Well, as I crossed many of the same intersections which it normally lags at, voila!, I had PERFECT position tracking. It stayed this way for several miles with consistently, need I say it again, PERFECT position placement.

Now comes the weird part. I decided to switch back to relative mode (or whatever it's called - where the top of the screen represents what is straight ahead of the vehicle, and the map rotates), and amazingly I still had perfect tracking (which I most definitely did not have prior to switching to North Up). I mean, even at 1/20 mile scale, when the tip of the red arrow touched an intersecting road on the map, the car was exactly in the center of that road. The rest of the way home, I did begin to notice some inconsistency from intersection to intersection, but overall it was a night and day difference.

I would love to see if anyone else can validate my results. I thought I was onto something with the idea regarding processing speed, but am totally confused with how it turned out. Please let me know if any of you get the same result.

 

I will have to try this to see if I get the same result. It would seem to make sense although I question how taxing simply rotating the screen is on the processor;its just a matter of occasionally turning the screen.

What I would think would cause slight lags is zooming in and out since for a split second the image is off the screen so it isnt being drawn? Or I dont know, Im tired, I just got back from work. I dont know what I'm talking about...

 

What exactly are we looking for? That the navi re-gains accuracy after having it's mode switched?

-jim

 

Yes, basically, although I tried the same experiment again this morning and it didn't work. In fact, it was worse than ever for a while, then settled down to its usual 100'-200' lag (at freeway speeds). So now I have no idea what happened. Maybe I was just lucky for 45 minutes or so last night. All I do know is that after switching modes yesterday, it was absolutely perfect, even zoomed in to the max. This has never happened before, even when the diagnostic screen indicates that I am tracking six satellites.

If this error weren't so consistent and so large, I would just accept it as the best that can be done with civilian GPS accuracy. I don't believe that this is true, however. For one, if this were due to GPS inaccuracy, I would expect to see deviations that are more random (sometimes lags, sometimes precedes actual location). Instead, the system ALWAYS lags (my temporary trip to the Twilight Zone last night notwithstanding). Therefore, this leads me to believe that the error is somehow due to a slight delay in processing and displaying the current location.

 

Could it be due to how many satellites its getting a signal from?

 

I gotta say one thing though; I have a Garmin 2610 in my other car and damn that thing is so sweet. So quick and accurate; and the best part it only costs $600. If it wasn't for the sleek look I'd preferred to stay with this GPS.

 

The fact that I have seen several messages from people who have said that this is the only nav system they have seen this lag on just reinforces my suspicion that our nav computer is a bit slow. Obviously, the GPS position and time information being received by each system is the same (assuming they have the same number of channels, etc.), so the only way the output could be different is if the computer interpreting it is doing something differently or more slowly.

Oh well, I'm sure it will be improved in the next generation of the system (you know, the one that every other Honda and Acura on the planet except the TL already has available....not that I'm bitter or anything ).

 

OK, thanks to this thread, I know now why Honda upgraded to a faster processor in the 4th-generation navi (it wasn't because of the new features). They could have upgraded the navi in the 06 TL to fix this "problem". Well, I hope potential 06 TL buyers are aware of this.