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:

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

   OK: 

   Mark appears. 

OK: NORMAL OPERATION 

NG: Go to next step 

1. Check that the vehicle is in a location where GPS signal reception is poor. If the vehicle is in such a place, relocate vehicle and check if the GPS mark reappears.

   HINT:

   The GPS uses 24 satellites in 6 orbits. At any point in time, 5 satellites should be able to pinpoint your vehicle. However, GPS signals may not reach the vehicle due to influence from the surroundings, vehicle direction and time. For illustrated examples, see below.

   Fig 1: Identifying Vehicle Location Where GPS Signal Reception Poor

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: 

   GPS mark is displayed. 

OK: RETURNS TO NORMAL 

NG: Go to next step 

1. Enter the Navigation Check mode's GPS Information (see NAVIGATION CHECK MODE  ).
   Fig 2: Diagnostic Tool Display - GPS Information

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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 appear. 

NG: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE 

OK: REPLACE NAVIGATION ECU