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 the 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 GPS Surroundings Location

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: GPS mark is displayed. 

NG: Go to step 3 

OK: SYSTEM RETURNS TO NORMAL 

1. Enter the "Navigation Check" mode (GPS Information) (See OPERATION CHECK  )
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: Diagnosis Display Screen - GPS Information

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

OK: REPLACE NAVIGATION ECU  (See REMOVAL  )