Hello all,

Can anyone guide me in the right direction of finding out how to replace the navigation antenna in the factory unit that came with the 2002 SC430?

In Diagnostics mode, there's no satellites detected...this means there's no signal to the unit.

If anyone has an inexpensive solution, please let me know.

Thanks!

 

Well the first obvious question is do you have line of sight to the sky? Believe it or not some people attempt to run the diagnostics from underground parking, or inside the garage.

The Nav antenna is located under the dash behind the display. Go to this thread, item #3....https://www.clublexus.com/forums/sc-...ntenna-is.html

 

Thanks,

I checked it outside in clear skies, and there's no signal from anywhere. I guess it's time for me to roll up my sleeves and remove the nav system.

 

I've had my Nav screen out. It's a PITA to get out of there.

You have to pull the climate module, the wood-covered side vent on the left side of the screen, the long wood panel on the right side of the screen, and there are like 4 bolts to get the whole assembly loose.

 

The scope of work is more than removing the nav unit. Unfortunately the antenna is located behind some AC ductwork and fastened to the underside of the instrument panel safety pad with screws that are applied from the wrong direction to be accessed from inside the car - so the factory procedure is to remove the glareshield and at least half the other stuff in the front of your car. It is a huge undertaking that might make one take a second look at a $200 Garmin unit. Of course as with any of these things there might be shortcuts but it doesn't look easy.

 

Gabe,
I couple of questions that may isolate the problem further... Back in the diagnostic screens
goto the GPS Information screen. What is displayed in the bottom left corner after the word Status: ??????? Just above the word status you should see Measurement Date (GMT). Anything there?

Then onto THE SERVICE check... Right side NAVI-ECU diagnostic screen .... what are the reading? Any DTC codes? Check out this below... asterisk and number tie back to the graphic on the left... Looking for a "40" "41" error code in the *12 area that points to the antenna, otherwise it probable the ECU. I sent you a PM too.

 

Status is '--'. The current date time is by GMT, nothing by measurement. How do I get to the service menu?

 

1.With the car stopped
2 set parking brake
3 turn ingnition to ACC or ON
4 push the display button for the Nav system
5 On the screen you should see a rectangle box between the word "display" at the top left and the contrast control at the bottom left.
Inside the box, touch top left corner, bottom left corner in that order three time in a row.
puts you into service mode

 

Once in service mode menu, press Unit Check to get to the "NAVI-ECU" in the right column

 

 

Now that you have a record of the codes, clear them by touching and holding the Code CLR button for 3+ seconds and lets see if the errors return or new error present.

 

Will do this step once I receive car back. Had to leave it at dealer to get the TPMS fixed, should get it back soon. So, what does the current codes mean?

 

Sent you an extensive PM

 

I reset statistics and it appears to be a bad antenna.
http://lexus.sewellparts.com/oem-cat...C430-2002.html

That antenna assembly costs $445.79 Part# 86860C . Is it worth it or should i try to go aftermarket?

Need advice

Thanks!