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

   OK: Mark appears. 

NG: Go to step 2 

OK: NORMAL OPERATION 

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

   HINT:

   The GPS uses 24 satellites in 6 orbits. At any point in time, 4 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. 

NG: Go to step 3 

OK: SYSTEM RETURN TO NORMAL 

1. Enter the "Navigation Check" mode (GPS Information) (See NAVIGATION CHECK MODE  ).
2. Check how many of the following codes appear in the "STS" column.

   For DENSO Made: T,P 

   For AISIN AW Made: 08H, 04H 

   OK: At least 3 codes appear. 

   Fig 2: Diagnostic Tool Display - GPS Information Screen

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

OK: REPLACE NAVIGATION ECU