I have been waiting and I have been search previous
thread also send pm to serveral member here to have solution for this,
however I couldnt fix this. If someone can help me in here I'd appreciate.

Here is the problem

I have 2007 IS250 WITH NAVIGATION (NO ML PKG)
I did Navigation hack (With on and off switch)
after navigation hack, I had to recalibrate every single time after I turn on
the Nav hack switch. GPS worked fine, everything seems fine if I turn off
the nav hack switch.

However, few weeks later, started having problem with GPS position,
now its about 150ft behind. More specifically, if I stop on the
traffic signal waiting for the right turns green, my navigation GPS is pointing at about 150ft behind the intersection and it goes to no where if I turn right or left, even if I manually recalibrate my position, it goes off again (not even 1/4 mile drive).

So, I decide to go back to normal setup,
disabled navigation hack, everything (wires) is went back to factory setup
and no switch or loop wire or anything, its completly factory setup.
BUT I am still having same problem, every day, in the morning
I manually recalibrate my GPS position, however if I get on the freeway
or complicate road, my gps goes no where. Let say, if I take left
at the intersection, my navigation GPS turn left at about 150 - 300ft
before the intersection and goes to somewhere else and same thing happening in Freeway.

Yes I have checked wire serveral times and everything done correctly
yes my car is 2007 not 2006 and no tint problem.

Any one have any idea?

Thank you for the reading

 

You are leaving out a VERY important piece of information. Familiarize yourself with the "GPS" indicator under the map scale on the top left of the display. It's what tells you that it has locked a GPS signal. When missing, the nav is using a speed sensor and gyro to calculate your position using dead reckoning.

In a properly working nav, the GPS indicator will appear within about 30 seconds of starting the car (assuming that the car isn't in a garage or parking structure), and will stay on constantly, extinguishing only when the car's view of the sky is blocked.

What is your GPS indicator doing?

 

not sure but wasnt there a updated navi disc for certain 07/06 models? wasnt it for the same reason? i didnt have this problem but thought i recall reading about this.

Like Bichon said make sure you are getting your GPS signal and it indicates on the upper left portion of the navi screen. its possible you knocked this loose on the back of the radio/navi unit? If you are back to normal mode and all is connected to the same wires and its not working there is something that isnt connected. my guess is some where you are not connected to the GPS antenna on the car. I would pull all back out and check for this and i think this will be the solution. Keep us posted.

 

They started shipping cars with the updated navi software towards the end of the 2006 model year. hojin4eva has a 2007, so he isn't affected by the TSIB.

 

I always start my car from inside of the garage..
hows the GPS indicator looks like? its not the compass?
and how can you tell whether this is locked or not?


So then, its probably some of the connector in the back is not connected
properly..? where is GPS antenna and how this look like? ..


THANK YOU EVERYONE.

 

It will say "GPS" underneath the North arrow.

 

Its not in there..


so then basically my GPS isnt working?

 

Make sure your car has a clear view of the sky before you look for the gps icon. Give it a few minutes to lock on a signal. If you get no signal, you need to retrace your steps, you may have left something disconnected.

 

Been drove 25 minute, but no GPS sign or indicator,
any specific wire you think of?
or its GPS antenna?

where do I can locate GPS antenna? if its attached to unit
what is it looks like?

again,,

Thank you everyone!!

 

It is more than likely that something is not connected properly when you revert your nav back to factory set up. One thing you can try is to reset the nav ecu. I don't recall the exact location of the fuse but its inside the fuse box underneath the steering wheel. You can look it up in the manual. The fuse is called "TV1". When you reset it, have the car on and pull the fuse. Your nav screen will go out. Then put the fuse back in after about a minute. You will see the nav reinstall the firmware.

Terrance

 

The GPS indicator is clearly visible on this picture, which I found in the gallery. It's in the white box in the upper left hand corner of the screen, under that map scale (0.5mi) indicator. If the word "GPS" isn't there, your navigation system is flying blind, using the speed sensor and gyroscope to calculate your position.

 

if you have been driving around and you cant get a GPS signal one of a few things has happened. You may have cutt another wire and didnt know you did? check to make sure all is connected tightly, maybe take everything off and reconnect again. check for a loose wire, i think its this personally but i dont know what the wire looks like to send you in the right direction. i will see if i can search for this and post a link if i can.

 

try this member: carchitect he is a tech for lexus and im sure they can look in the service guide to tell you what wire. i did a search and wasnt able to find anything more then we have with the nav hack.

also thy Technique, he is very good with this also and may be of help.

Let me know how it goes and if you get it to work. at this point maybe just to take apart and double check everything one last time might be worth the time and with a fresh start you just may find it

 

First of all,

Thank you everyone,

I dont have that GPS sign like Bichon's picture,
I guess its GPS problem.

My question is, it worked fine after Nav hack (for about 2 weeks)
and eventually didnt work, fact is that I didnt touch anything,
like Terrance said, it can be a FUSE problem?
I am pretty sure that its not a wire problem because if its wire problem then
it shouldnt work in first place(right after Nav hack)?

I should try to reset the fuse...

 

Yes then see what that does? sorry didnt know it was working after the nav hack. thought it wasnt working since you did that...its still could be a wire "or" plug for the GPS antenna that came loose? i wish i could find something so we know what it looks like.