Jump to content
AVIC411.com

Multiple Issues: GPS & XM


Recommended Posts

I just had a small shop with a good reputation install a z120bt in my wife's Acadia. I'm having a few issues, however.

 

1. The XM audio cuts out from time-to-time. The channel will show up, but there is either static or no audio at all.

 

2. The GPS always knows generally where we are at, but it does not place us on a road. It's like we're off-roading or something.

 

The XM is using an aftermarket tuner & both antenna are sitting the top-side of the dash right next to one another. I read that the 2 might be causing issues with one another. How far apart should they be & in what direction should the GPS antenna be installed? The guy who put it in has the antenna sideways as opposed to facing forward. I keep getting an error message that says G-sensor is installed incorrectly.

 

Please help, my wife's about to kill me!

Link to post
Share on other sites

Does having them on the dash work or should they be run to the outside of the car? Also, does the direction the sensor is facing effect the function of the GPS? Right now, it's turned sideways & I keep getting the aforementioned error message.

 

The GPS antenna, if mounted on the dash, should be set on the included metal sheet. It needs a metal backplane to receive the satellite signals.

 

The G sensor error sounds like a different problem. The only mention of "G Sensor" in the Z120 manual is on p.199:

Positioning by “Dead Reckoning"

The built-in sensor in the navigation system also calculates your position. The current location is measured by detecting driving distance with the speed pulse, the turning direction with the “Gyrosensor†and inclination of the road with the “G sensorâ€. The built-in sensor can even calculate changes of altitude, and corrects for discrepancies in the distance traveled caused by driving along winding roads or up slopes.

So this is a built-in sensor, not the GPS antenna. That is why VBlue asked about the mounting angle. It should not be tilted more than 30 degrees(Installation manual p.21). If it is not tilted, this error might indicate a hardware problem with your unit.

Oh, the orientation of the antenna (direction it is facing) doesn't matter.

 

Link to post
Share on other sites

But the XM & GPS issues I'm having could just be a result of the antenna's being too close together or could this g-sensor be causing some of this? As I understand it, the G-sensor just picks-up the slope the car is on

 

 

As VBlue said, they should be separated by at least 6". That could solve some or all of your problems. If you bought this unit from this "reputable" shop, then take it back - it's their problem.

 

If you bought it on ebay - or grey-market, I guess its your problem, but I would first go back to the installer. First try moving the antenna apart. Should just be magnetically attached to the dash. If it is glued or something else, you paid way too much for the installation. I would guess there is enough slack in the wire to move them apart without much trouble. See if that fixes or improves your GPS issue.

 

I don't have XM, but if I understand the other posts, you are not using the Pioneer tuner? That could be a problem.

 

The G-sensor and gyro are used to approximate your position. They are all inputs to the GPS chip. So your final position will not be as reliable if you have sensor issues. Did they install VSS? If not, you didn't receive a professional installation.

 

You can see GPS, VSS readings. Press Home/Settings/Navi Settings/Connection Status. Speed Pulse is the VSS signal.

G sensor (incline) and gyro data can be seen on the 3D Calibration Status screen.

 

BTW, it takes some time for the AVIC NAV system to calibrate itself. You may want to recalibrate it by clearing the statuses for Distance, Speed Pulse, and Learning Status. See P149 in the Z120 manual. If you bough it used, you probably should do this. The sensors calibrate based on the environment in which they are installed.

Link to post
Share on other sites
  • 4 weeks later...

I know depending on the car and such being on the dash is not good enough. I've never heard of the two canceling each other but I would rule that out I'm just saying I've had mine next to each other several times with no problems on the Z1 and Z2. The problem I was having was line of site threw the wind shield. Especially if your window isn't slanted a lot then the roof will cut the line of site and function will dip. not a positive fix for your issue but something to think about if nothing else works.. I believe it was a Grand Am and a Dodge Ram I couldn't get it to work on the dash.

Link to post
Share on other sites

Update...Moving the antennae apart fixed all the XM issues. Now the only issue is with the GPS. At times, the GPS thinks I'm off-roading & it when I slow down to stop, the map keeps moving forward & then it thinks I'm in the middle of a field. When I turn onto a different road, it realizes I've turned & then it puts me in the correct spot. This isn't typically a problem, but if my wife is driving downtown & there are lots of streets, it's an issue. Any help is appreciated! This has become one giant hassle.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...