Inspection Procedure

1. Check the cabin for any object that might interrupt radio reception on the instrument panel. If such an object exists, remove it and check if the GPS mark reappears.

HINT:

GPS works using extremely weak radio waves originating from satellites. If the signal is interrupted by obstructions or another radio wave, the GPS system may not be able to properly receive the signal.

OK: Mark appears. 

1. OK: NORMAL OPERATION 
2. NG: GO TO NEXT STEP 

1. Check if the vehicle is in a location where GPS signal reception is bad. If the vehicle is in such a place, move it elsewhere and check if the GPS mark reappears.

HINT:

• GPS uses 24 satellites in 6 orbits so that at any time 4 satellites will be in line-of-sight of your vehicle.
• GPS signals may not be received, however, based on surroundings, vehicle direction, and time.
• The following illustrations show some conditions where it may be difficult to receive GPS signals.

Fig 1: Identifying Locations Where GPS Signal Reception Is Bad

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: GPS mark is displayed. 

1. OK: RETURNS TO NORMAL 
2. NG: GO TO NEXT STEP 

1. Enter the "Navigation Check" mode (GPS information) (see NAVIGATION CHECK MODE (GPS INFORMATION) ).
2. Check how many of the following codes occur in the "STS" column

   For DENSO Models: T, P 

   For AISIN AW Models: 04H, 08H 

   OK: At least 3 codes occur. 

Fig 2: Navigation Check Mode Screen (GPS Information)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. OK: REPLACE RADIO AND NAVIGATION ASSY (SEE  RADIO RECEIVER ASSY  ) 
2. NG: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN  PROBLEM SYMPTOMS TABLE