Inspection Procedure

WARNING: This page is about a different car, the 2007 Lexus GX 470. However, it is still accessible from the selected car via links, so may be relevant.

CHECK CABIN
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.
  
  OK: NORMAL OPERATION
  
  NG: Go to Next Step
CHECK SURROUNDINGS
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.
  
  Fig 1: Checking GPS Signal In Different Location
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  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 examples, see illustration below.
  
  OK: GPS mark is displayed.
  
  OK: SYSTEM RETURN TO NORMAL
  
  NG: Go to Next Step
CHECK GPS INFORMATION (NAVIGATION CHECK MODE)
1. Enter the "NAVIGATION CHECK" MODE (GPS Information).
  
  Fig 2: Identifying Tester Display - GPS Information
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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.
  
  NG: PROCEED TO NEXT INSPECTION PROCEDURE SHOWN IN PROBLEM SYMPTOMS TABLE
  
  OK: REPLACE NAVIGATION ECU