[tonymdx]

I have been having a couple of problem with the navigation system.

1. Heading down a freeway (605 in los angeles) When ever i go past an off ramp the nav system shows me heading down the off ramp and onto the side streets. sometimes is always shows me on a parallel street to the one i am on (this happens a lot of times and always corrects its self after a few momments)

2. the street that I am driving down is always shown at an angle of about 10 degrees of of 180. What i mean is that when your driving down a street say south. the maps shows the street as a vertical line on the display. mine shows as an angle line. the red arrrow is pointing up. I know this can be adjusted and i have many times but once the car is stopped it goes back to the angle view.

has anyone had any of these problems ???

Thanks
Tony

 

[Rail]

Have you gone into the setup page and calibrated the Nav system?

Find a large square block and cal. it out - it should be better after that.

Oh, how many green bars do you have in the icon in the upper left? There should be 3 if the Nav is reading all 3 satellites.

Rail

 

[tonymdx]

i have calibrated it before, using the location correction when i do that the roads appear vertical on the map. but then it goes back to the way it is now.
Also i do have three bars.

is there a way the dealer can check this. when i talked to the service guy he told me that there was sometimes problems with the satelite ????

 

[TheWorm]

The problem with the Nav -- any Nav -- placing you on a parallel frontage road rather than the freeway itself is fairly common and might be normal in your case. We don't have many frontage roads here in NorCal so I haven't experienced it in either of our cars (MDX or GS).

Relevant thread/discussion: http://www.acuramdx.org/forums/showthread.php?s=&threadid=1509&highlight=frontage+road

I noticed in Houston (with a Hertz rental and Everlost, and where there are tons of frontage roads parallel to the freeways) that it frequently thought I was on a frontage road (didn't have that problem with Everlost in any other city I've used it). There's just not enough seperation between the parallel road and the freeway for it to tell -- unless there's an algorithm it's using based on speed ("hmm, this guy's going 75, so he must be on the fwy rather than the side road").

Dunno what to tell you about the "not at 180'" part. I'll see if ours is that way...but must admit I'm not entirely clear on what you mean by "the map shows vertical but mine shows as an angle...". What map?

 

[mcclendons]

The "problems" with the satellite would have to do with accuracy, not the condition you are indicating. GPS is affected by atmospherics (scintillation causing accuracy errors) and the fact that we can't access the military improved accuracy. That said, GPS accuracy is very good, just some days better than others. once in while, it may think you are on a parallel road, but that should be fairly rare and only when the roads are close (10M or so).


The issue you are describing sounds to me like it may be more related to Gyro drift/alignment. In effect, the Gyro tells the map you are going due North when you are really going N North East (for example). I belive this because 1) since when you do an alignment, it worked fine, but 2) then goes back to the skewed view after a restart. Does it also go off course if you will after driving for a long time, or only after the car is turned off? If it tends to be related to the time the system runs, it sounds like pure Gyro drift. If it is ONLY after the car is shut off, sounds like the system alignment is not being maintained in the system and it is not self calibrating.

Either way, sounds to be a problem with your NAV unit, assuming you have not change the wiring in any way or remounted the NAV unit (reason is that when titled the Gyro can hang up and not work well, must be fairly flat). Would ask the dealer to replace, or have him take you for a drive in one of their units (does not need to be MDX) and show you that the NAV in that car behaves the same (and it won't) Good Luck

 

[Rail]

Okay - looking in the service manual:

In the icon:

No satellite mark - 2 or less satellites
Yellow satellite mark - 3 satellites
Green satellite mark - 4 or more

I always have a green icon in S. Cal.

If you've recal'd and you have a yellow or green icon - then you should take it in to your dealer. It may be set up for a different US region - where did you buy your MDX?

BTW to get into the diagnostics - turn on your ignition, press OK for the disclaimer, then press and hold the MENU, MAP/Guide and Cancel keys (in that order) for 5 seconds.

Press System Links

While it's diagnosing the system - all the links will be drawn in yellow - if everything's OK, then the connecting lines will be green, you'll get an OK and you'll hear a tone. If a problem is found, then the bad connection will be drawn in red and it'll show NG and a tone will sound.

After checking this page you need to reset the system - do that by turning your ignition key to OFF. You can then restart and come back to the diagnostics screen.

Go to UNIT CHECK -

DO NOT USE FORCE DOWNLOAD

Press GPS - and it'll show you the GPS reception condition, and your vehicle position.

CAR STATUS checks different conditions/sensors:

VSP - OFF when the MDX is not moving, ON when it is.
BACK - ON when in reverse, otherwise OFF

NAV ECU

When any of the listed items is NG - the Nav system is bad.

Don't press Backup Clear

Turn off your ignition to reset.

If you feel at all uncomfortable doing/looking at this stuff on yor system - I'd highly recommend that you take your MDX into your dealer for warranty repair.

Best of luck.

Rail

 

[TheWorm]

mcclendons,

Interesting post and info. FWIW I'm not certain that the "calibration" (of moving the car around on the map itself) does anything permanently except if you don't have a sat signal at all; I think it might only be a temporary measure to restore accuracy once it's been lost (like after driving around in an underground garage).

By temporary, I mean it isn't saved once you shut off the car and then restart later...doesn't reset the defaults but is only good while the same "session" is happening.

The owners manual is unclear as is the service manual on whether these settings are "saved" after shutdown. The stuff accessible through Rail's diags (for Nav and other trip/computer functions are saved, however.

If that makes any sense...

 

[Rail]

Hi Worm

I believe that the cal. does stick -- I had a problem where my Nav was off by 30 feet -- a recal fixed it and I've never had the problem since.

I should mention that there are certain situations where the Nav can get - shall we say confused - and it will tell you you're somewhere where you're not (usually an adjacent road). However I've only had this happen a couple of times - normally on the 405 near Skirball, it'll tell me I'm on Sepulveda if I'm going less than 40mph... otherwise it's been fine.

Best regards (and a Happy Thanksgiving).

Rail

 

[TheWorm]

Thanks for the "it sticks" confirmation. I'd go out to the garage and play with it, but it's family-day afterall

Happy Thanksgiving to you to!

 

[mcclendons]

As Rail mentioned, the calibration settings are saved. A main saved setting has to do with the speed pulse sensor. Every mile you drive, the Nav computer compares the speed pulse distance to the distance from GPS and tries to calibrate speed pulse. After driving some distance, the speed pulse becomes very accurate and constant. The GPS is fairly accurate, but its errors tend to be somewhat random (a few M west, few east etc). The Gyro calibration is also done and saved (Reason for not only driving in straight line but through turns).

The only reason I can think for your path not being straight up (provided that option is selected) is that the Gyro is telling the unit your path is different than the road direction. If is just one road, could be a mapping error on the database. Sounds in your case like it can be any road. That given, sounds the Gyro is drifting. Checking out the diagnostics is a good idea, but even if they come out OK, I would force the dealer to show me same issue in another car.